®

Eaton No. 06-06-638

EN-0300
Medium Duty Piston Pump (Replaces 06-638)

Parts Information

Model 70160 Variable Displacement Piston Pump

20,3 cm3/r [1.24 in3/r] or 23,6 cm3/r [1.44 in3/r] Displacements
Manual Controlled v-02
Model 70160

2
Model 70160

Identification Numbers - Manually Variable Displacement Piston Pump

Stamped on each unit's mounting flange.
Single Pump - Product Number:
A - Product Number Description
70160 = Single Piston Pump
7 0 1 6 0 - R A A - 02
78162 = Single Piston Pump with Gear Pump
78161 = Tandem Piston Pumps A B C
78163 = Tandem Piston Pumps with Gear Pump
B - Sequential Numbering
C - Engineering Design Code Tandem Pumps - Product Number:
7 8 1 6 3 - R A B - 02
A B C
Serial Number Code:
A 98 01 31 JB
Revision level of parts list. Tester's Initials

Last two digits of year built. Day of Month (two digits)

( 98 for 1998 etc.)
Month (two digits)

Each order must include the following information.

1. Product and/or Part Number
2. Serial Number Code
3. Part Name
4. Quantity

Tools Required
1/2, 9/16, 7/8 & 1-1/8 in. sockets and/or end wrenches
Torque wrench (136 N.m [100 lbf.ft] capacity)
Ratchet wrench
5/16 in. and 7/16 Allen wrenches or bit sockets
Internal and external retaining ring pliers
Small screwdrivers (2)
Hammer (soft face)
Light Petroleum Jelly
Seal driver or similar tool

3
Model 70160

Parts Drawing
Pump drawn below is typical of a right hand pump.

48

4
14
17 Port 22 Press Fit 13
(D1) 5
50
50-1
12
24
39
Press Fit into
Cover plate
41 22 Press Fit
30
3
3-1
Press Fit

41
Shaft assembly for 51-1 14
single pump
29 1 51 39
or front pump
of tandem. Port 40
(D2)
16
Press Fit
23
8
10 1 Shaft assembly for 17
9 rear pump of tandem.
10
8
6
11
7 8
10
9
10
8
11
7

4
Model 70160

Parts Drawing 55-1

49 55-2
49-1 K2-4
55-3 K1
55
55-4
55-5
K2-3
19 K1-1 32
19-1 28 (K2-2)
18
21 27 28
37 K2
K2-3

27
26
K2-2

20 32
(K2-1)
18
2-2 2 19-1 K4
26 2-1 19 K4-3

33
(K3-3) K4-2
K3 37 32
(K4-4)
(K4-1)

31 34
32
(K3-2) 34-1
(K3-1)
28A
36
19 55-1
49 55-2 27A
49-1
55-3
55
55-4
55-5
19-1
18
35 27B
21
46

46
37

26

20
18
2-1 2-2 19-1
26 2 19

5
Model 70160

Parts List
Parts listed below are to service catalog units. Other variations of units are built that have parts altered for special requirements.
The non-catalog units can be serviced with the parts list below using caution for proper identification. Contact an Eaton
representative with any questions concerning your selection. Have your final assembly number ready when contacting
representative.
Item 02 Part No. Qty. Description
1 ♦ 1 Drive Shaft (Identification drawing on page #8)
2 ♦ 1 Endcover Assembly (Identification drawing and parts list on page #9)
3 ♦ 1 Housing Assembly (Identification drawing on page #10)
3-1 16238-11616 1 Bearing (Press Fit)
4 70111-692 1 Rotating Kit Assembly (parts list on page #10)
5 1 Swashplate, 20,3 cm3/r [1.24 in3/r] Displacement
70160-623 Square Arm
70160-617 Tapered Arm
5 1 Swashplate, 23,6 cm3/r [1.44 in3/r] Displacement
70160-620 Square Arm
70160-618 Tapered Arm
6 16048-312 1 Washer
+ 7 16077-26 1 Retaining Ring
+ 8 16078-16 2 Retaining Ring
9 16241-1625 1 Thrust Bearing
10 16241-C1625 2 Bearing Race
+ 11 16253-16 1 Shaft Seal, Drive
11 16253-216 1 Viton Shaft Seal, Drive
11 70102-636 1 Spacer
+ 12 70111-701 1 Housing Gasket
13 70160-504 1 Swashplate Insert
14 106013-038 6 Washer
+ 16 16253-214 1 Shaft Seal, Trunnion
17 16136-610 6 Screw, Cap
18 17086-017 2 Spring
19 32060-8 2 Plug Assembly
+ 19-1 16015-18-90 2 O-ring, 2,38 mm Dia. x 22,23 mm ID. [.0937 in. Dia. x .875 in. ID.]
20 ♦ 1 Relief Valve for Port "C" (Identification drawing on page #11)
21 ♦ 1 Relief Valve for Port "D" (Identification drawing on page #11)
22 16320-117 2 Cone Bearing
23 70160-508 1 Cover Plate
24 70160-510 1 Cover Plate
26 16028-304 2 Dowel Pin
27 16136-520 2 Cap Screws, 5/16-18, 50,8 mm [2 in.] Long
27A 16136-532 2 Cap Screws, 5/16-18, 82,6 mm [3.25 in.] Long
27B 16136-534 2 Cap Screws, 5/16-18, 88,9 mm [3.5 in.] Long
28 16136-524 2 Cap Screws, 5/16-18, 63,5 mm [2.5 in.] Long
28A 16136-536 2 Cap Screws, 5/16-18, 95,3 mm [3.75 in.] Long
28B 16136-540 2 Cap Screws, 5/16-18, 101,6 mm [4.00 in.] Long
29 1 Key, Drive Shaft
24500-619 Used with 7/8 in. dia. drive shaft.
30 16246-430 1 Key, Tapered Arm
31 70142-600 1 Cover Plate (In K3 kit)
+ 32 16007-14 1 O-ring (In K1, K2, K3, & K4 kit)
33 16036-610 2 Cap Screws, Cover Plate (In K3 kit)
34 16103-108 1 Plug Assembly
+ 34-1 16133-8 1 O-ring, 2,21 mm Dia. x 16,36 mm ID. [.087 in. Dia. x .644 in. ID.]
+ 35 70111-703 1 Molded O-ring
36 ♦ 1 Charge Pump Adaptor (Identification drawing and parts list on page #12 & #13)
37 1 Gerotor set and coupler sub-assembly
70111-642 6,9 cm3/r [.42 in3/r] displacement, 6,35 mm [.25 in ] width
70111-646 13,8 cm3/r [.84 in3/r] displacement, 12,7 mm [.5 in] width
6
Model 70160

Parts List
Item 02 Part No. Qty. Description
37 70111-667 1 9 tooth coupler (In Kit 4)
37 70111-687 1 11 tooth coupler (In Kit 5)
39 16321-117 2 Cup, Bearing
40 N/S 1 Ring, Crush (Shim kit must be ordered to replace crush ring).
41 16015-46 2 O-ring, 2.38 mm Dia. x 66.68 mm I.D. [.0937 in. Dia. x 2.625 in. I.D.]
42 106013-031 4 Washer
46 70111-632 1 Mounting Bracket, Square shaped
46 70111-709 1 Mounting Bracket, "V" shaped
48 ♦ 1 Valve Plate (Identification drawing on page #11)
70113-008 Righthand (CW) Rotation
70113-009 Lefthand (CCW) Rotation
+ 49 16103-108 1 Plug Assembly
49-1 16133-8 1 O-ring, 2,21 mm Dia. x 16,36 mm I.D. [.087 in. Dia. x .644 in. I.D.]
50 16103-308 1 Plug Assembly
+ 50-1 16133-8 1 O-ring, 2,21 mm Dia. x 16,36 mm I.D. [.087 in. Dia. x .644 in. I.D.]
51 16103-308 1 Plug Assembly
+ 51-1 16133-8 1 O-ring, 1,98 mm Dia. x 11,89 mm ID. [.078 in. Dia. x .468 in. ID.]
55 70300-610 1 Bypass Valve sub-assembly
+ 55-1 16078-6 1 Retaining Ring
55-2 70300-609 1 Separator Plug
55-3 70411-502 1 Separator
+ 55-4 16003-7 1 O-ring, 1,59 mm Dia. x 9,53 mm I.D. [.0625 in. Dia. x .375 in. I.D.]
+ 55-5 16133-8 1 O-ring, 2,21 mm Dia. x 16,36 mm I.D. [.087 in. Dia. x .644 in. I.D.]

Mounting Kits
K1 70142-944 1 Tandem Piston Pump Mounting Kit
K1-1 70111-666 1 35T Coupler, 36,8 mm [1.45 in.] long
K1-2 16007-14 1 O-ring, 1,59 mm Dia. x 101,6 mm ID. [.0625 in. Dia. x 4 in. ID.]
K1-3 16136-613 2 Cap Screws
K1-4 16048-8 2 Washer
K2 70442-929 1 Gear Pump Mounting Kit
K2-1 16007-14 1 O-ring, 1,59 mm Dia. x 82,55 mm ID. [.0625 in. Dia. x 3.25 in. ID.]
K2-2 16048-113 2 Washer
K2-3 16136-612 2 Cap Screws
K3 70142-915 1 Cover Plate Kit
K3-1 16007-14 1 O-ring, 1,59 mm Dia. x 82,55 mm ID. [.0625 in. Dia. x 3.25 in. ID.]
K3-2 70142-600 1 Cover Plate
K3-3 16136-610 2 Cap Screws
K4 70144-903 1 Gear Pump Mounting Kit with Coupler
K4-1 16007-14 1 O-ring, 1,59 mm Dia. x 101,6 mm ID. [.0625 in. Dia. x 4 in. ID.]
K4-2 16048-113 2 Washer
K4-3 16136-612 2 Cap Screws
K4-4 70111-667 1 9T Coupler

Seal Repair Kit

70160-902 1 Seal Repair Kit for 70160 piston pump.
70160-903 1 Control Shaft Shim Kit (to replace crush ring (40) after replacment of cover plate).

Legend ♦ Refer to specific item parts list.

+ Common parts to seal repair kits.
N/S Not Serviceable

7
Model 70160

Item 1 - Drive Shaft Identification

Part Number Input Drive Where Used Output Drive

9 Tooth
.81 Min. Full Depth
or
rot
h Ge
, wit
u mp 9 Tooth
le P
S ing .81 Min. Full Depth

ro tor
Ge
ith
,w
u mp
eP 9 Tooth
70142-200 [13 Tooth] gl
Sin r
.625 Min. Full Depth
to
ero
oG
m p, N
le Pu 9 Tooth
70142-203 [7/8 in. Keyed] S ing .625 Min. Full Depth
or
e rot
oG
p ,N
um
gl eP 35 Tooth
70142-215 [13 Tooth] Sin or
rot
.76 Min. Full Depth
e
oG
m p, N
Pu
nt
Fro 9 Tooth
70142-225 [7/8 in. Keyed] d em
Tan r oto
r .625 Min. Full Depth
e
oG
p ,N
P um
ar 9 Tooth
Re
70142-201 [13 Tooth] dem .81 Min. Full Depth
or
Tan ero
t
G
ith
m p, w
70142-212 Pu
[35 Tooth] .69 Min. Full Depth Rear
de m
Tan

70142-214
[35 Tooth] .69 Min. Full Depth

8
Model 70160

Item 2 -
Endcover Assembly Identification
Item 2 - Parts List (Refer to Identification chart and drawings)
Bypass Valve
Item Part Number Qty. Description Location
2 See chart below Endcover Assembly
2-1 70420-43 1 Bearing
2-2 16026-610 1 Roll Pin 2-3
2-3 16133-6 1 O-ring 2-4
2-4 70111-711 1 Charge Relief Housing
2-5
2-5 70111-507 1 Poppet Filter Relief 2-6
2-6 17000-48B 1 Spring (100-150 PSI) 2-7
2-7 16048-260 1 Washer 2-8
2-8 16077-10 1 Retaining Ring 2(d)
2-9 70400-508 1 Bleed-off Valve Poppet Rear "A" Mount, Opposite Side
2-10 17023-12 1 Spring Porting with Charge Relief
2-11 16133-5 1 O-ring
2-12 70400-501 1 Cartridge

Bypass Valve Bypass Valve

Bypass Valve
Location Location
Location

2(a) 2(b) 2(c)

2-1
Bearing
2-2 Mounting
Roll Pin 2-9 Holes Both Sides

2-10
2-11
2(a) 2(b) 2-12 2(c)
Accepts Gerotor Rear "A" Mount, Rear "A" Mount, Same Side
Charge Pump Opposite Side Porting Porting with Mounting Holes

Item 2 - Endcover Assembly Identification (Refer to drawings above)

Charge Bypass Charge Relief Charge Relief
Item Part Number Pump Main Port Valve to Case Setting bar [PSI] Special Feature
2(a) 70119-005 Yes Opposite Sides* Yes No ---- ----
2(b) 70117-021 No Opposite Sides* Yes No ---- ----
2(c) 70121-022 No Same Side* Yes Yes 6,89-10,34 Bleed Off & Mounting Holes
[100-150]
2(d) 70117-023 No Opposite Sides* Yes Yes 6,89-10,34 ----
[100-150]
* Port Size: 1 1/16-12 UN-2B

9
Model 70160

Item 3 - Housing Assembly Identification

Item 3 -
Housing Assembly Identification
Item Part Number Port Machined
3 70160-307 D1 & D2
3 113077-001 D1, D2, & D4

DRAIN PORT - D1 (TOP)

3/4-16 UNF-2B
SAE O-RING PORT

DRAIN PORT - D4 (FRONT)

DRAIN PORT - D2 (BOTTOM)

3/4-16 UNF-2B
SAE O-RING PORT
(PLUG OPTIONAL)

Item 4 - Rotating Kit Assembly

4-9
4-7
4-8
4-7
4 4-6
4-5 Item 4 - Rotating Kit Assembly
Item Part Number Qty. Description
4-4
4-2 4-3 4 70111-692 1 Rotating Kit Assy.
4-1 NSS 9 Piston Assembly
4-2 NSS 1 Shoe Retainer
4-1 4-3 NSS 1 Shoe Retainer Pivot
4-4 NSS 1 Pin retainer
4-5 NSS 1 Cylinder Barrel
4-6 NSS 3 Pins
4-7 NSS 2 Washer
4-8 NSS 1 Spring
4-9 NSS 1 Retaining Ring
NSS - Not Sold Separately
10
Model 70160

Item 20 or 21 - Relief Valve

Item 20 or 21 -
Internal Relief Valve Settings Available
Part Number bar [PSI]
32060-LA 138 [2000]

32060-LA
2000
32060-QA 172 [2500]
32060-UA 207 [3000]
32060-WA 241 [3500]
32060-ZA 276 [4000]
32060-XA 310 [4500] Assembly Number
32060-IA 345 [5000] and Pressure Setting
70111-518 Seat, Valve

Item 48 - Valve Plate

Low Cam Lefthand Righthand
Effort Valving Rotation Rotation
both Rotations Note "V" notch
Identification Numbers Bronze Side location
on Bronze Face of of Valve Plate
( ) ( ) ( )
Valve Plate -0
07
-0
09
-0
08
12 13 13
1

1
70

70

70

Steel Side
of Valve Plate

Back Side
No Grooves

11
Model 70160

Item 36 -
Charge Pump Adapter Assembly Identification
Configuration for
13,8 to 17,2 bar [200 to 250 PSI] or
36-4a 17,2 to 20,7 bar [250 to 300 PSI]
36-3a or 3b Charge Relief Valve
36-2a

Right Hand Rotation Pressure Check Port or

Remote Charge Port
36-4
Configuration for 36-3 36-1
6,9 to 10,3 bar 36-2
[100 to 150 PSI] Charge Pump
Charge Relief Valve Suction Port
Bearing
Gerotor Ring
Pocket
Gerotor Pocket Depth (See chart for
depth)
Displacement Depth of Pocket
cm3/r [in3/r] mm [in]
36
6,9 [.42] 6,35 [.25]
13,8 [.84 12,7 [.50]

Configuration for
13,8 to 17,2 bar [200 to 250 PSI] or
17,2 to 20,7 bar [250 to 300 PSI]
Charge Relief Valve 36-4a
36-3a or 3b
Left Hand Rotation 36-2a
Pressure Check Port or
Remote Charge Port
36-4
36-1 36-3
36-2 Configuration for
6,9 to 10,3 bar
Charge Pump
[100 to 150 PSI]
Bearing Suction Port
Charge Relief Valve

Gerotor Ring
Pocket
(See chart for
36 depth)

12
Model 70160

Item 36 -
Charge Pump Adapter Assembly

6,9 to 10,3 bar [100 to 150 PSI] Charge Relief Setting

Item Part No. Qty. Description Rotation Displacement
36 70142-314 1 Assembly, Charge Pump Adapter Righthand 6,88 cm3/r [.42 in3/r]
70142-306 1 Assembly, Charge Pump Adapter Lefthand 13,8 cm3/r [.84 in3/r]
70141-397 1 Assembly, Charge Pump Adapter Righthand 13,8 cm3/r [.84 in3/r]
70142-359 1 Assembly, Charge Pump Adapter Lefthand 6,88 cm3/r [.42 in3/r]
36-1 16239-1148 1 Bearing (press fit)
36-2 70111-507 1 Poppet, Cup
36-3 17000-48B 1 Spring, Tapered
36-4 70400-505 1 Spring Retainer

13,8 to 17,2 bar [200 to 250 PSI] Charge Relief Setting

Item Part No. Qty. Description Rotation Displacement
36 70142-373 1 Assembly, Charge Pump Adapter Lefthand 6,88 cm3/r [.42 in3/r]
70142-377 1 Assembly, Charge Pump Adapter Righthand 6,88 cm3/r [.42 in3/r]
70142-380 1 Assembly, Charge Pump Adapter Righthand 13,8 cm3/r [.84 in3/r]
70142-385 1 Assembly, Charge Pump Adapter Lefthand 13,8 cm3/r [.84 in3/r]
36-1 16239-1148 1 Bearing (press fit)
36-2a 70400-685 1 Poppet, Pin
36-3a 17056-40 1 Spring, Color "Light Green"
36-4a 70400-512 1 Spring Retainer

17,2 to 20,7 bar [250 to 300 PSI] Charge Relief Setting

Item Part No. Qty. Description Rotation Displacement
36 70142-376 1 Assembly, Charge Pump Adapter Righthand 6,88 cm3/r [.42 in3/r]
70142-381 1 Assembly, Charge Pump Adapter Lefthand 6,88 cm3/r [.42 in3/r]
70142-386 1 Assembly, Charge Pump Adapter Lefthand 13,8 cm3/r [.84 in3/r]
36-1 16239-1148 1 Bearing (press fit)
36-2a 70400-685 1 Poppet, Pin
36-3b 17056-41 1 Spring, Color "Pink"
36-4a 70400-512 1 Spring Retainer

13
 ACCREDITED BY
THE DUTCH COUNCIL
Eaton Hydraulics FOR CERTIFICATION
Reg. No. 24

15151 Highway 5 46 New Lane, Havant ISO-9001 CERTIFICATED FIRM

Eden Prairie, MN 55344 Hampshire PO9 2NB DET NORSKE VERITAS INDUSTRY BV, THE NETHERLANDS

Telephone: 952 937-7254 England Quality System Certified

Products in this catalog are
Fax: 952 937-7130 Telephone: (44) 170-548-6451 manufactured in an
www.eatonhydraulics.com Fax: (44) 170-548-7110 ISO-9001-certified site.

06-06-638 Copyright Eaton Corporation, 2000

EN-0300 All rights reserved.
Printed in U.S.A
 06-06-642
Eaton ®
EN-0800
(Replaces 06-642)
Medium Duty Piston Pump

Parts Information

Model 72400
Servo Controlled Piston Pump v-04
Model 72400

Parts
Drawing
Pump drawn below is typical of a righthand
rotation with porting out the left side of pump.

34
36
47 14

48 26 8
10
61
7 51 53
16
12 28-3 28-4-3
28-3-1
28-6 38 52
38-1 28-4
18
11 28-4-1 28-5
28-4-2

40
40-1
39-1
39
Serial Code and
Product Number 28-6
Location
41-1 9
28-2 41
28-1 12
17
30 61
7
31

4 31 6
19
20 Shaft assembly for 60 2
19 rear pump of tandem.
4
37
43
3
4
19
20
19
4
45
3

2
Model 72400

Parts
Drawing
K1

21 K1-3
29
21-1

Assembly for Front K1-4

pump of Tandem 23 K1-1
K1-2
29-2
K3
57
35
29-1 57-1 25
22-1 62
46 32
27 44
22

K2
24
Assembly for single pump
or rear pump of tandem. 21 35
49 K2-1
29
21-1 62 32

50 42
42
29-2 Inner Gerotor
33 49
and
57 56 11 tooth Coupler

55
56
29-1 57-1
22-1
27
22
Valve Plate
Identification

Note "V" notch

locations

Lefthand Righthand
Rotation Rotation

3
Model 72400

Parts List
Item Part No. Qty. Description
2 16024-6 1 Jam Nut
+ 3 16077-32 1 Retaining Ring
+ 4 16078-18 2 Retaining Ring
+ 6 16254-6 1 Seal Washer
7 16147-310 8 Cap Screw, #10-24, 25,4 mm [1.0 in.] Long
8 → 1 Rotating Kit Assembly (parts list on page 6)
9 113684-001 1 Servo Piston Assembly (parts list on page 6)
10 72400-585 1 Servo Piston Follower
11 72400-620 1 Cover Plate
+ 12 72400-621 2 Cover Plate Gasket
+ 14 72400-626 1 Housing Gasket
+ 16 72400-631 1 Control Housing Gasket
17 72400-651 1 Cover Plate
18 72400-677 1 Swashplate
19 74308-100 2 Thrust Race
20 74308-101 1 Thrust Bearing
21 → 1 Relief Valve for Port "A" (parts list on page 7)
+ 21-1 16133-12 1 O-ring, 2,95 mm Dia. x 23,47 mm I.D. [.116 in. Dia. x .924 in. I.D.]
22 → 1 Relief Valve for Port "B" (parts list on page 7)
+ 22-1 16133-12 1 O-ring, 2,95 mm Dia. x 23,47 mm I.D. [.116 in. Dia. x .924 in. I.D.]
23 16136-622 4 Cap Screw, 3/8-16, 57,2 mm [2.25 in.] Long
24 16136-634 2 Cap Screw, 3/8-16, 88,9 mm [3.5 in.] Long
25 16136-640 2 Cap Screw, 3/8-16, 101,6 mm [4.0 in.] Long
26 16147-314 6 Cap Screw
27 1 Valve Plate, 2.48 in3/r
70344-51 Righthand (CW) Rotation
70344-52 Lefthand (CCW) Rotation
28 → 1 Housing Assembly (Identification on page 7)
28-1 → 1 Housing (Identification on page 7)
28-2 16238-11816 1 Bearing (press fit)
28-3 025083-002 1 Plug Sub-Assembly
+ 28-3-1 008785-002 1 O-ring, 1,63 mm Dia. x 6,1 mm I.D. [.064 in. Dia. x .239 in. I.D.]
28-4 112258-001 1 Cradle Sub-Assembly
28-4-1 16028-404 2 Dowel Pin
28-4-2 112256-001 1 Bushing
28-4-3 16269-106 2 Cap Screw, Button Head
28-5 16148-506 2 Cap Screw
+ 28-6 72400-583 2 Seal Sub-Assembly
29 → 1 Endcover Assembly (Identification on page 8)
29-1 52200-23 1 Bearing (press fit)
29-2 16026-610 1 Roll Pin
30 16246-516 1 Key
31 → 1 Drive Shaft (Identification on page 9)
72400-200 15 tooth, 16/32 DP - w/ 41 tooth, 48/96 DP (Tandem Front Pump)
72400-201 41 tooth, 48/96 DP - w/ 11 tooth, 16/32 DP (Tandem Rear Pump)
72400-202 41 tooth, 48/96 DP - w/ 9 tooth, 16/32 DP (Tandem Rear Pump)
72400-204 15 tooth, 16/32 DP - w/ 9 tooth, 16/32 DP (Single Pump)
72400-211 13 tooth, 16/32 DP - w/ 9 tooth, 16/32 DP (Single Pump)
72400-212 15 tooth, 16/32 DP - w/ 11 tooth, 16/32 DP (Single Pump)
72400-213 25.4 [1.00] Dia. Str., w/ keyway - w/ 9 tooth,16/32 DP (Single Pump)
+ 32 16007-14 1 O-ring,1.59 mm Dia. x 82.55 mm I.D. [.0625 in. Dia. x 3.25 in. I.D.]
+ 33 72400-646 1 Molded O-ring
34 16021-4 1 Nut
35 16032-610 2 Cap Screw, 3/8-16, 25,4 mm [1.0 in.] Long
36 16045-104 1 Lockwasher
37 16048-319 1 Washer

4
Model 72400

Parts List
Item Part No. Qty. Description
38 16103-308 1 Plug
+ 38-1 16133-8 1 O-ring, 2,21 mm Dia. x 16,36 mm I.D. [.087 in. Dia. x .644 in. I.D.]
39 16103-308 1 Plug
+ 39-1 16133-8 1 O-ring, 2,21 mm Dia. x 16,36 mm I.D. [.087 in. Dia. x .644 in. I.D.]
40 16103-312 1 Plug
+ 40-1 16133-12 1 O-ring, 2,95 mm Dia. x 23,47 mm I.D. [.116 in. Dia. x .924 in. I.D.]
41 16103-312 1 Plug
+ 41-1 16133-12 1 O-ring, 2,95 mm Dia. x 23,47 mm I.D. [.116 in. Dia. x .924 in. I.D.]
42 1 Key
16246-429 Used with 9 tooth internal spline through shafts
16246-431 Used on 11 tooth drive coupler with 12,7 mm [.5 in.] width gerotor
16244-443 Used on 11 tooth drive coupler with 6,35 mm [.25 in.] width gerotor
+ 43 16253-18 1 Shaft Seal, Standard
43 16253-218 1 Shaft Seal, Viton
44 70142-600 1 Cover Plate
45 70400-620 1 Spacer
46 → 1 Charge Pump Adapter Assembly (parts list & ID. on Page 10 &11)
47 72400-506 1 Control Arm
48 → 1 Servo Control Assembly (parts list & ID. on Page 12 &16)
49 1 Inner Ring Gerotor (match displacement with Item 46 & 50)
79004-611 6,9 cm3/r [.42 in3/r] displacement, 6,35 mm [.25 in.] width
79004-605 13,8 cm3/r [.84 in3/r] displacement, 12,7 mm [.5 in.] width
72400-673 6,9 cm3/r [.42 in3/r] displacement (used with Item 55 coupler)
72400-640 13,8 cm3/r [.84 in3/r] displacement (used with Item 55 coupler)
50 1 Outer Ring Gerotor (match displacement with Item 46 & 49)
79004-612 6,9 cm3/r [.42 in3/r] displacement, 6,35 mm [.25 in.] width
79004-606 13,8 cm3/r [.84 in3/r] displacement, 12,7 mm [.5 in.] width
51 → 1 Supply Orifice (orifice chart on page 17)
52 → 1 Control Valve Orifice (orifice chart on page 17)
53 → 1 Control Valve Orifice (orifice chart on page 17)
55 72400-639 1 Coupler, 11 tooth
56 72400-638 2 Retaining Ring, (used with Item 55)
57 1 Bypass Valve
113578-001 Bypass Valve Actuator
16103-108 Plug (selected when bypass valve is not required)
57-1 16133-8 1 O-ring, 2,21 mm Dia. x 16,36 mm I.D. [.087 in. Dia. x .644 in. I.D.]
60 16254-26 1 Washer
61 16048-672 8 Washer
62 106013-038 4 Washer

Kits
K1 72400-902 1 Tandem Servo Piston Pump Mounting Kit
K1-1 70411-622 1 Coupler, 41 tooth
+ K1-2 16007-17 1 O-ring, 1,59 mm Dia. x 101,6 mm I.D. [.0625 in. Dia. x 4 in. I.D.]
K1-3 16032-812 2 Cap Screw, 1/2-13, 31,75 mm [1.25 in.] Long
K1-4 16048-72 2 Washer
K2 70442-929 1 Gear Pump Mounting Kit
Includes Items 32 and 35
K2-1 16048-113 2 Washer
K3 70142-915 1 Cover Plate Kit for "A" SAE Flange Series 82-2 Mount
Includes Items 32, 35, and 44
72400-908 1 Seal Repair Kit for single pump (Two required for tandem units).
72400-916 1 Seal Repair Kit for single pump with Viton shaft seal (Two required for tandem units).

Legend → Refer to specific Item parts list.

+ Parts included in 72400-908 Seal Repair kit.

5
Model 72400

Item 8 - Rotating Kit Assembly 8-9

Item 9 - Servo Piston Assembly 8-8

8-7

8-7
8-6
8-5

8-4
Item 8
8-2 8-3
Rotating Kit Assembly
Item Part No. Qty. Description
8 70300-603 1 40,6 cm3/r [2.48 in3/r]
8-1 70400-703 1 49,2 cm3/r [3.00 in3/r]
8-1 NSS 9 Piston Assembly
8-2 NSS 1 Shoe Retainer
8-3 NSS 1 Shoe Retainer Pivot
8-4 NSS 1 Retainer
8-5 NSS 1 Cylinder Barrel
8-6 NSS 3 Pins
8-7 NSS 2 Washer
8-8 NSS 1 Spring
8-9 NSS 1 Retaining Ring

NSS - Not Sold Separately

9-1

Note: Do not disassemble servo

piston assembly.

9-2
9-3
Item 9
Servo Piston Assembly 9-4

Item Part No. Qty. Description

9 113684-001 1 Servo Piston Assy.
9-1 NSS 1 Servo Piston
9-5
9-2 NSS 1 Servo Piston Bolt
9-3 NSS 2 Spring Retainer
9-4 NSS 1 Spring Stop
9-3
9-5 NSS 1 Spring
9-6
9-6 NSS 1 Nut (Loctited)
9-7 NSS 1 Jam Nut 9-7
9-8 NSS 1 Retaining Ring 9-8

NSS - Not Sold Separately

6
Model 72400

Item 21 or 22 - Relief Valve S/A

Item 28 - Housing Identification

Item 21 or 22
Internal Relief Valve Settings Available
Part Number bar [PSI]

110603-200 138 [2000]

110603-250 172 [2500]
110603-300 207 [3000]
110603-350 241 [3500] Dash Number Stamped here
110603-400 276 [4000] for Valve Pressure Setting Identification
110603-450 310 [4500] Example: 500 x 10 = [5000 PSI] 345 bar
110603-500 345 [5000]

Item 28
Housing Identification

"A" Auxiliary Port

"C" Drain Port

"E" Drain Port

"B" "D" Drain Port
Auxiliary Port

Housing Assy. Housing

Item Part No. Item Part No. Qty. Port Machined

28 112259-001 28-1 72373-001 1 A, B, C, D

28 112259-012 28-1 72373-012 1 A, B, C, D, E
28 112259-013 28-1 72373-013 1 A, B, E

7
Model 72400

Item 29 -
Endcover Assembly
Identification
Parts List
Item Part No. Qty. Description

29 Chart Below 1 Endcover Assembly

29-1 52200-23 1 Bearing (press fit)
29-2 16026-610 1 Roll Pin

Item 29 - Endcover Assembly Part Number Identification

Item 29
Endcover Assembly
Rear Mounting Support Hole Part Number
Rear "B" Mount with Hole 113585-002
(no gerotor charge adapter) None 113585-001
Accepts Gerotor Charge Pump with Hole 113581-002
Adapter with "A" Mount None 113581-001
Rear "A" Mount with Hole 113583-002
(no gerotor change adapter) None 113583-001

Accepts Support Hole 2 Bolt SAE "B" or "A"

Support Hole
Charge Adapter Rear Mounting
Port "A" Port "A"

29 29
Port "B" Port "B"
29-2 29-2

29-1 29-1

8
Model 72400

Item 31 -
Drive Shaft Identification

Input Drive Part Number Where Used Output Drive

p) 41 Tooth
m
Pu
nt
Fro
d em
(Tan
0 11 Tooth
-20
)
mp
4 00 rP
u
72 Re
a
d em 9 Tooth
(Tan
1 Internal
-20 m p)
15 Tooth
4 00 ar
Pu
72 Re
m
n de 9 Tooth
2 (Ta Internal
41 Tooth 0
0-2
40 p)
72 m
Pu
ngle
4 (Si 11 Tooth
41 Tooth 0
0-2
40 p)
72 m
Pu
le 9 Tooth
ng
2 (Si Internal
1
15 Tooth 0-2
40 p)
72 m
Pu
le
ng
(Si
15 Tooth -213
4 00
72

1 in. Keyed

9
Model 72400

Item 46 -
Charge Pump Adapter Assembly

Bearing

46-2
46-1

Gerotor Ring
Pocket
Bushing
Gerotor Pocket Depth
Displacement Depth of Pocket
cm3/r [in3/r] mm [in.]

6,9 [.42] 6,35 [.25] 46-6

13,8 [.84] 12,7 [.50] Righthand Rotation
Adapter Shown
Charge Pump
46-5 Suction Port

46-4
46-3-1

46-3

Item Part No. Qty. Description

46 See Chart 1 Assembly, Charge Pump Adapter

46-1 NSS 1 Charge Pump Adapter
46-2 16239-1148 1 Bearing (press fit), Used w/9 tooth output shaft
46-2 72400-637 1 Bushing (press fit), Used w/11 tooth output shaft
46-3 72400-659 1 Plug
+ 46-3-1 16133-10 1 O-ring
46-4 16048-597 ƒ Shims
46-5 17059-16 1 Spring
46-6 72400-682 1 Poppet

ƒ - Shim as required
NSS - Not sold separately

10
Model 72400

Item 46 -
Charge Pump Adapter Identification

Lefthand Rotation Righthand Rotation

Charge Relief Valve Charge Charge
Suction Port
Return Outlet Port
Open
Path Open Port
Path

Detail B Detail D Detail C

Detail D Detail C Detail B

Open
Open Path
Path
Charge
Return Port Charge
Suction Port
Outlet Port Charge
Relief Valve

Adapter, Item 46,

Identification Chart

9 Tooth Output Shaft 11 Tooth Output Shaft

3 3
Refer 6,9 cm /r 13,8 cm /r 6,9 cm3/r 13,8 cm3/r
Charge Shaft to
to [.42 in3/r] [.84 in3/r] [.42 in3/r] [.84 in3/r]
Pump Routing Rotation Detail Displacement Displacement Displacement Displacement
Charge Righthand B & D 72356-010 72356-011 72348-010 72348-011
Relieved to Case Lefthand B&D 72358-010 72358-011 72360-010 72360-011
Remote Filter and Righthand B & C 72356-007 72356-008 72348-007 72348-008
Charge
Relieved to Case Lefthand B&C 72358-007 72358-008 72360-007 72360-008

11
Model 72400

Item 48 -
Servo Controller Assemblies
48-2
48-3
48-5
48-6
48-5
48-16
48-4 48-7

48-15
48-14
48-1

Wide Band Neutral Spool

Identification Mark

Destroke Valve 48-8

Option
48-12
48-10

48-9
48-13
48-17
48-11 (press fit)
48-21

48-20 Neutral Lockout

Switch Option

48-28
48-19-2A 48-26
48-19-2 48-19-2B
48-19-2C 48-25
48-24
48-19-1 48-23
48-19 48-18
48-22

48-27

48-30
48-29

Neutral Detent
12 Option
Model 72400

Item 48 -
Servo Controllers - Parts List
Index of Controllers Page 72401-AA
72401-AA with No Additinal Features 13 Item Part No. Qty Description
48 72401-AA Assembly with no additional features
72401-AD with Destroke Valve 13 48-1 72319-001 1 Control Housing
72401-AE with Neutral Detent & Wide Band 48-2 72400-507 1 Plug
Neutral 13 + 48-3 16015-8 1 O-ring
48-4 16124-31 1 Retaining Ring
72401-AF with Neutral Detent, Destroke Valve 48-5 72400-504 2 Spring Retainer
& Wide Band Neutral 14 48-6 17073-14 1 Spool Centering Spring
72401-AG with Wide Band Neutral 14 48-7 72400-563 1 Valve Spool - Standard
48-8 102149-019 1 Set Screw
72401-AH with Destroke Valve & Wide Band 48-9 72400-502 1 Feedback Link
Neutral 14 48-10 72400-508 1 Dowel Pin
72401-AR with Neutral Lockout, Destroke Valve 48-11 16124-15 1 Retaining Ring
& Wide Band Neutral 15 48-12 72400-519 1 Bell Crank
48-13 16139-304 1 Set Screw
72401-AS with Neutral Lockout & Wide Band 48-14 72400-505 1 Input Shaft
Neutral 15 + 48-15 16003-5 1 O-ring
72401-AL with High Gain Control 16 + 48-16 16074-106 1 Wiper Seal
48-17 72400-520 1 Headed Pin (press fit)

72401-AD 72401-AE
Item Part No. Qty Description Item Part No. Qty Description
48 72401-AD Assembly with Destroke Valve Assembly with Neutral Detent & Wide
48 72401-AE
48-1 72319-003 Control Housing Band Neutral
48-2 72400-507 1 Plug 48-1 72319-005 1 Control Housing
+ 48-3 16015-8 1 O-ring 48-2 72400-507 1 Plug
48-4 16124-31 1 Retaining Ring + 48-3 16015-8 1 O-ring
48-5 72400-504 2 Spring Retainer 48-4 16124-31 1 Retaining Ring
48-6 17073-14 1 Spool Centering Spring 48-5 72400-504 2 Spring Retainer
48-7 72400-563 1 Valve Spool - Standard 48-6 17073-14 1 Spool Centering Spring
48-8 102149-019 1 Set Screw 48-7 72400-544 1 Valve Spool - Wide Band Neutral
48-9 72400-502 1 Feedback Link 48-8 102149-019 1 Set Screw
48-10 72400-508 1 Dowel Pin
48-9 72400-502 1 Feedback Link
48-11 16124-15 1 Retaining Ring
48-10 72400-508 1 Dowel Pin
48-12 72400-519 1 Bell Crank
48-11 16124-15 1 Retaining Ring
48-13 16139-304 1 Set Screw
48-12 72400-519 1 Bell Crank
48-14 72400-505 1 Input Shaft
48-13 16139-304 1 Set Screw
+ 48-15 16003-5 1 O-ring
+ 48-16 16074-106 1 Wiper Seal
48-14 72400-505 1 Input Shaft
48-17 72400-520 1 Headed Pin (press fit) + 48-15 16003-5 1 O-ring
48-18 16003-6 2 O-ring + 48-16 16074-106 1 Wiper Seal
48-19 72420-AE 1 Destroke Valve Assy. 48-17 72400-520 1 Headed Pin (press fit)
48-19-1 72400-719 1 Manifold 48-29 98193 1 Ball Plunger
Destroke Valve w/12 VDC 48-30 101335 1 Nut, Seal
48-19-2 72400-521 1
coil, Weatherpak Conn.
48-19-2A 16133-10 1 O-ring
48-19-2B 16101-102 2 Back-up Washer
48-19-2C 16015-2 1 O-ring
48-20 16045-103 2 Lock Washer
48-21 16148-316 2 Cap Screw

13
Model 72400

Item 48 - Servo Controllers - Parts List

72401-AF 72401-AH
Item Part No. Qty Description Item Part No. Qty Description
Assembly with Neutral Detent, Assembly with Wide Band Neutral &
48 72401-AH
48 72401-AF Destroke valve & Wide Band Destroke Valve
Neutral 48-1 72319-003 Control Housing
48-1 72319-006 1 Control Housing 48-2 72400-507 1 Plug
48-2 72400-507 1 Plug + 48-3 16015-8 1 O-ring
48-4 16124-31 1 Retaining Ring
+ 48-3 16015-8 1 O-ring
48-5 72400-504 2 Spring Retainer
48-4 16124-31 1 Retaining Ring
48-6 17073-14 1 Spool Centering Spring
48-5 72400-504 2 Spring Retainer
48-7 72400-544 1 Valve Spool - Wide Band Neutral
48-6 17073-14 1 Spool Centering Spring
48-8 102149-019 1 Set Screw
48-7 72400-544 1 Valve Spool - Wide Band Neutral 48-9 72400-502 1 Feedback Link
48-8 102149-019 1 Set Screw 48-10 72400-508 1 Dowel Pin
48-9 72400-502 1 Feedback Link 48-11 16124-15 1 Retaining Ring
48-10 72400-508 1 Dowel Pin 48-12 72400-519 1 Bell Crank
48-11 16124-15 1 Retaining Ring 48-13 16139-304 1 Set Screw
48-12 72400-519 1 Bell Crank 48-14 72400-505 1 Input Shaft
48-13 16139-304 1 Set Screw + 48-15 16003-5 1 O-ring
48-14 72400-505 1 Input Shaft + 48-16 16074-106 1 Wiper Seal
+ 48-15 16003-5 1 O-ring 48-17 72400-520 1 Headed Pin (press fit)
+ 48-16 16074-106 1 Wiper Seal 48-18 16003-6 2 O-ring
48-17 72400-520 1 Headed Pin (press fit) 48-19 72420-AE 1 Destroke Valve Assy.
48-18 16003-6 2 O-ring 48-19-1 72400-719 1 Manifold
Destroke Valve w/12 VDC coil,
48-19 72420-AE 1 Destroke Valve Assy. 48-19-2 72400-521 1
Weatherpak Conn.
48-19-1 72400-719 1 Manifold
48-19-2A 16133-10 1 O-ring
Destroke Valve - w/12 VDC 48-19-2B 16101-102 2 Back-up Washer
48-19-2 72400-521 1
coil, Weatherpak Conn.
48-19-2C 16015-2 1 O-ring
48-19-2A 16133-10 1 O-ring 48-20 16045-103 2 Lock Washer
48-19-2B 16101-102 2 Back-up Washer 48-21 16148-316 2 Cap Screw
48-19-2C 16015-2 1 O-ring
48-20 16045-103 2 Lock Washer
48-21 16148-316 2 Cap Screw
48-29 98193 1 Ball Plunger
48-30 101335 1 Nut, Seal

72401-AG
Item Part No. Qty Description
48 72401-AG Assembly with Wide Band Neutral Spool
48-1 72319-001 1 Control Housing
48-2 72400-507 1 Plug
+ 48-3 16015-8 1 O-ring
48-4 16124-31 1 Retaining Ring
48-5 72400-504 2 Spring Retainer
48-6 17073-14 1 Spool Centering Spring
48-7 72400-544 1 Valve Spool - Wide Band Neutral
48-8 102149-019 1 Set Screw
48-9 72400-502 1 Feedback Link
48-10 72400-508 1 Dowel Pin
48-11 16124-15 1 Retaining Ring
48-12 72400-519 1 Bell Crank
48-13 16139-304 1 Set Screw
48-14 72400-505 1 Input Shaft
+ 48-15 16003-5 1 O-ring
+ 48-16 16074-106 1 Wiper Seal
48-17 72400-520 1 Headed Pin (press fit)

14
Model 72400

Item 48 - Servo Controllers - Parts List

72401-AR 72401-AS
Item Part No. Qty Description Item Part No. Qty Description
Assembly with Neutral Lockout, Assembly with Neutral Lockout &
48 72401-AR 48 72401-AS
Destroke valve & Wide Band Neutral Wide Band Neutral
48-1 72319-004 1 Control Housing 48-1 72319-002 1 Control Housing
48-2 72400-507 1 Plug 48-2 72400-507 1 Plug
+ 48-3 16015-8 1 O-ring + 48-3 16015-8 1 O-ring
48-4 16124-31 1 Retaining Ring 48-4 16124-31 1 Retaining Ring
48-5 72400-504 2 Spring Retainer 48-5 72400-504 2 Spring Retainer
48-6 17073-14 1 Spool Centering Spring 48-6 17073-14 1 Spool Centering Spring
48-7 72400-544 1 Valve Spool - Wide Band Neutral 48-7 72400-544 1 Valve Spool - Wide Band Neutral
48-8 102149-019 1 Set Screw 48-8 102149-019 1 Set Screw
48-9 72400-502 1 Feedback Link 48-9 72400-502 1 Feedback Link
48-10 72400-508 1 Dowel Pin 48-10 72400-508 1 Dowel Pin
48-11 16124-15 1 Retaining Ring 48-11 16124-15 1 Retaining Ring
48-12 72400-519 1 Bell Crank 48-12 72400-519 1 Bell Crank
48-13 16139-304 1 Set Screw 48-13 16139-304 1 Set Screw
48-14 72400-505 1 Input Shaft 48-14 72400-505 1 Input Shaft
+ 48-15 16003-5 1 O-ring + 48-15 16003-5 1 O-ring
+ 48-16 16074-106 1 Wiper Seal + 48-16 16074-106 1 Wiper Seal
48-17 72400-520 1 Headed Pin (press fit) 48-17 72400-520 1 Headed Pin (press fit)
+ 48-18 16003-6 2 O-ring + 48-22 16133-8 1 O-ring
48-19 72420-AE 1 Destroke Valve Assy. 48-23 72400-722 1 Adapter Assy., Neutral Lockout
48-19-1 72400-719 1 Manifold 48-24 16006-6 1 Ball
Destroke Valve - w/12 VDC + 48-25 16003-500 1 O-ring
48-19-2 72400-521 1
coil, Weatherpak Conn. 48-26 72400-546 1 Pin
+ 48-19-2A 16133-10 1 O-ring 48-27 102149-019 1 #10-32, Set Screw
+ 48-19-2B 16101-102 2 Back-up Washer 48-28 109791-001 1 Neutral Lockout Switch Assy.
+ 48-19-2C 16015-2 1 O-ring
48-20 16045-103 2 Lock Washer
48-21 16148-316 2 Cap Screw
+ 48-22 16133-8 1 O-ring
48-23 72400-722 1 Adapter Assy, Neutral Lockout
48-24 16006-6 1 Ball
+ 48-25 16003-589 1 O-ring
48-26 72400-725 1 Pin
48-27 102149-019 1 #10-32, Set Screw
48-28 109791-001 1 Neutral Lockout Switch Assy.

15
Model 72400

Item 48 -
High - Gain Servo Control Assembly - Parts List

72401-AL
Item Part No. Qty Description
48 72401-AL Assembly with High Gain Servo Control
48-1 72401-500 1 Control Housing
48-2 72401-505 1 Plug
+ 48-3 16015-8 1 O-ring
48-7 72401-516 1 Valve Spool - High Gain
48-8 102149-019 1 Set Screw
48-9 72401-508 1 Feedback Link Weldment
48-14 72401-502 1 Input Control Shaft
+ 48-16 72401-503 1 Wiper Seal
+ 48-31 16133-2 1 O-ring
48-32 72401-506 1 Plug
+ Included in Seal Repair Kit 72400-915

48-2
48-3 48-16

48-7 High Gain

48-14
48-1

48-8

48-31
48-32

48-9

72401-AL Assembly

16
Model 72400

Item 51, 52, or 53 -

Orifice Sizes Available

Item 51,52, or 53
Orifice Sizes Available
Hole Dia.
Part Number mm [inches]

101619-021 0,53 [.021]

101619-028 0,71 [.028]
101619-036 0,91 [.036]
101619-040 1,02 [.040]
101619-044 1,12 [.044] XX
101619-048 1,22 [.048]
101619-052 1,32 [.052]
101619-057 1,45 [.057] Last two digits
101619-065 1,65 [.065] of dash number
101619-073 1,85 [.073] stamped on face
101619-094 2,38 [.094] of orifice.
101619-102 2,59 [.102]

17
Model 72400

18
Model 72400

19
 Each order must include the following information.
1. Product and/or Part Number
2. Serial Number Code
3. Part Name
4. Quantity

Identification Numbers - Servo Control Piston Pump

Stamped on each units mounting flange.
Single Pump - Product Number:
A - Product Number Discription
72400 = Single Piston Pump
72400 - 002- 04
78461 = Tandem Piston Pump
78462 = Single Piston Pump with Gear Pump A B C
78463 = Tandem Piston Pumps with Gear Pump
B - Sequential Numbering
C - Design Code Number Tandem Pumps - Product Number:
78461 - 002- 04
A B C
Serial Number Code:
B 91 01 31 JB
Revision level of parts list. Testers Initials

Last two digits of year built. Day of Month (two digits)

( 91 for 1991 etc.)
Month (two digits)

ACCREDITED BY
THE DUTCH COUNCIL
Eaton Hydraulics FOR CERTIFICATION
Reg. No. 24

15151 Highway 5 46 New Lane, Havant ISO-9001 CERTIFICATED FIRM

Eden Prairie, MN 55344 Hampshire PO9 2NB DET NORSKE VERITAS INDUSTRY BV, THE NETHERLANDS

Telephone: 952 937-7254 England Quality System Certified

Products in this catalog are
Fax: 952 937-7130 Telephone: (44) 170-548-6451 manufactured in an
www.eatonhydraulics.com Fax: (44) 170-548-7110 ISO-9001-certified site.

06-06-642 Copyright Eaton Corporation, 2000

EN-0800 All rights reserved.
Printed in U.S.A
 ® No. 6-615
Eaton January 1998

Medium Duty Piston Pump

Parts and Repair

Information

Model 70122, 0 -19 cm3/r [0-1.16 in3/r] Displacement

Pressure or Pressure-Flow Compensated Piston Pumps
Model 70122

Introduction
Table of Contents
Introduction ......................................................................................................... 2
Identification ........................................................................................................ 3
Tools Required .................................................................................................... 3
Parts Drawing ...................................................................................................... 4
Parts List ............................................................................................................. 5 -12
Item 1 - Drive Shaft ID .................................................................................. 6
item 2 - Backplate Assembly ......................................................................... 7
Item 4 - Compensator Assembly and Parts List ............................................ 8 -9
Factory Pre-set Compensator Assemblies ..................................................... 10
Item 5 - Rotating Kit ...................................................................................... 11
Product Number ............................................................................................ 12
Repair information ............................................................................................... 13 - 15
Disassembly .................................................................................................. 13
Inspection ..................................................................................................... 14
Reassembly ................................................................................................... 15
Start-up Procedure .............................................................................................. 16
Fault-Logic Troubleshooting ................................................................................ 17 - 19

Introduction
This manual provides service information for the Eaton Models 70122 Pressure or Pressure - Flow
Compensated Piston Pumps. Step by step instructions for the complete disassembly, inspection, and
reassembly of the pump are given. The following recommendations should be followed to insure successful
repairs.

Remove the pump from the application.

Cleanliness is extremely important.
Clean the port areas thoroughly before disconnecting the hydraulic lines.
Plug the pump ports and cover the open hydraulic lines immediately after they're disconnected.
Drain the oil and clean the exterior of the pump before making repairs.
Wash all metal parts in clean solvent.
Use compressed air to dry the parts. Do not wipe them dry with paper towels or cloth.
The compressed air should be filtered and moisture free.
Always use new seals when reassembling hydraulic pumps.
Lubricate the new rubber seals with a petroleum jelly (Vaseline) before installation.
Torque all bolts over gasketed joints, then repeat the torquing sequence to make-up for gasket
compression.
Verifying the accuracy of pump repairs on an authorized test stand is essential.
2
Model 70122

Identification and Tools Required

Identification Numbers - Pressure or Pressure-Flow Compensated Piston Pump
Stamped on each units mounting flange.

A - Product Number Description Single Pump - Product Number:

70122 = Single Piston Pump
B - Rotation 70122 - RAA
L - Lefthand (CCW)
R - Righthand (CW) A
C - Sequential Numbering
B C

Serial Number Code:

B 93 01 31 JB
Revision level of parts list. Testers Initials

Last two digits of year built. Day of Month (two digits)

( 93 for 1993 etc.)
Month (two digits)

Serial Number Code prior to Jan., 1992:

1 B- 52-JB
Year Manufactured Testers Initials
(1 for 1991 etc.)
Week of Year
Change Code

Tools Required

• 1/2 Inch Socket • Internal Retaining Pliers (Straight .070 Tip)

• 1-1/8 Inch End Wrench • External Retaining Pliers (Straight .070 Tip)
• 11/16 Inch End Wrench • Regular or Locking Pliers
• Rachet Wrench • Seal Driver or Similar Tool
• Torque Wrench (100 lb./ft.) • Petroleum Jelly (Such as Vaseline)
• 3/16 Inch Hex Key (Allen) • 5/16 I.D. x 15/16 O.D. flat washer (2 ea.)
• 3/16 Inch Hex Key (Allen Socket) • 5/16 x 2-7/8 N.C. Cap screw (1 ea.)
• Soft Face Hammer • 5/16 N.C. Nut

3
Model 70122

Parts
Drawing
Pump drawn below is typical of a righthand rotation pump.
6
9
11 22 23
20
26 18
19
25
3
3-2
Serial code and
assembly number location

25
1 19
26
32 20
11
3-1

4 14

10 28
16
15
16
10
13
17
12 8
(Cover only)
7 24 27
21

5
2

All left (CCW) or right (CW) directions

given are viewed from the input shaft end of the pump.
4
Model 70122

Parts List
Item Part No. Qty. Description
1 ♦ 1 Drive Shaft (Identification drawing on page #6)
2 ♦ 1 Backplate Assembly (Identification drawing on page #7)
3 70102-301 1 Housing Assembly, .5625-18 - SAE Straight Thread O-ring Port - Right side of housing
3-1 16238-11616 1 Bearing
3-2 16026-608 2 Roll Pin
4 ♦ 1 Compensator Assembly (Identification drawing on page #8, 9 & 10)
5 ♦ 1 Rotating Kit Assembly (parts list on page #11)
6 70120-602 1 Camplate
7 70120-401 1 Control Piston
8 70422-618 2 Cover
9 16026-507 1 Roll Pin
+ 10 16078-16 2 Retaining Ring
+ 11 16077-24 2 Retaining Ring
+ 12 16077-26 1 Retaining Ring
13 16048-312 1 Washer
14 16148-412 4 Cap Screws
15 16241-1625 1 Thrust Bearing
16 16241-C1625 2 Bearing Race
+ 17 16253-16 1 Shaft Seal
17 16253-216 1 Shaft Seal, Drive (fluorocarbon rubber)
18 17073-6 1 Spring
19 70101-150 2 Inner Race
20 70111-622 2 Trunnion Cover
+ 21 70111-701 1 Gasket
22 70120-600 1 Spring Collar
23 70120-601 1 Button
+ 24 70422-600 1 Gasket
25 76100-191 2 Thrust Bearing
+ 26 16015-25 2 O-ring, 3/32 x 1-5/16 ID
27 16032-512 4 Cap Screw
+ 28 16003-5-90 1 O-ring, 1/16 x 1/4 ID 90 DUR
32 16246-427 1 Key, Used on 19.05 [.75] diameter shaft
32 24500-619 1 Key, Used on 22.2 [.875] diameter shaft

Seal Repair Kit

• 70122-902 1 Seal Repair Kit

Legend ♦ Refer to specific item parts list.

+ Included in seal repair kits listed.

5
Model 70122

Item 1 - Drive Shaft Identification

Item 1
Drive Shaft Identification
Part Number Input Drive

70122-203,
22.2 [.875] Dia. keyed

70102-200, 13 Tooth

70122-200,
19.05 [.75] Dia. keyed

70102-201, 13 Tooth
w/ Retaining Ring Groove

6
Model 70122

Item 2 - Backplate Assembly

2-2
2-2-1

2-3
(Loctited)

2-1 2(a) 2(b)

Item 2 - Parts List
Lefthand Righthand
Rotation Rotation
Item Part No. Part No. Qty. Description
2(a) 70120-311 70120-309 1 Rear Porting Backplate Assembly
2(b) 70120-314 70120-318 1 Opposite Side Porting Backplate Assembly

2-1 70420-43 1 Bearing

2-2 16103-103 2 Plug Assembly
+ 2-2-1 16133-3 2 O-ring, 1.59 mm Dia. x 7.54 mm I.D.
[.0625 in. Dia. x .2969 in. I.D.]
2-3 70120-400 1 Guide Pin
Legend + Included in seal repair kit listed on page 5.

All left (CCW) or right (CW) directions

given are viewed from the input shaft end of the pump.

Lefthand Rotation Righthand Rotation

(CCW) (CW)
7
Model 70122

Item 4 - Compensator Assembly

Pressure-Flow Compensator Pressure Compensator

*4-11 *4-11 *4-11

Cover Cover Cover

non-set non-set non-set

4(a) 70422-HU 4(b) 70422-HY 4(c) 70422-HR
Lefthand (CCW) Pump Rotation Righthand (CW) Pump Rotation Fits Both Pump Rotations
(Righthand (CW) rotation shown)
*4-11, Cover not included with non-set compensator assy.

4-7
4-19
4-19-1 4-8

4-9
4-10
4-2 4-11
4-3
4-4
4-5
4-1 4-6
4-14
4-12 4-16
4-13
4-15

4-17
4-18
4-9
All left (CCW) or right (CW) directions
4-10
given are viewed from the input shaft end of the pump. 4-11
8
Model 70122

Item 4 - Compensator Parts List

Item 4 - Parts List (Refer to drawings)
Item Part No. Qty. Description
4(a) 70422-HU 1 Non-Set Pressure-Flow Compensator Assembly, Lefthand Rotation
4(b) 70422-HY 1 Non-Set Pressure-Flow Compensator Assembly, Righthand Rotation
4(c) 70422-HR 1 Non-Set Pressure Compensator Assembly
4-1 N/S 1 Compensator Body
4-2 N/S 1 Pressure Spool
4-3 70422-405 1 Spring Pivot Cap
4-4 17063-11 1 Spring
+ 4-5 16003-11 1 O-ring, 2.38 mm Dia. x 14.29 mm I.D. [.0937 in. Dia. x .5625 in. I.D.]
4-6 70421-453 1 Pressure Spring Follower
+ 4-7 16015-18 1 O-ring, 2.38 mm Dia. x 22.23 mm I.D. [.0937 in. Dia. x .875 in. I.D.]
4-8 70422-606 1 Adjustment Cap, Pressure
4-9 70422-620 1or2 Set Screw
4-10 16024-4 1or2 Nut
4-11* 70422-618* 1or2 Cover*
4-12 N/S 1 Flow Spool
4-13 70411-411 1 Spring Pivot Cap
4-14 17029-5 1 Spring
+ 4-15 16003-4-90 1 O-ring, 1.59 mm Dia. x 5.55 mm I.D. [.0625 in. Dia. x .2187 in. I.D.]
4-16 70421-477 1 Flow Spring Follower
+ 4-17 16133-6 1 O-ring, 1.98 mm Dia. x 11.89 mm I.D. [.078 in. Dia. x .468 in. I.D.]
4-18 70422-602 1 Adjustment Cap Flow
4-19 16103-103 2 Plug Assembly
+ 4-19-1 16133-3 2 O-ring, 1.59 mm Dia. x 7.54 mm I.D. [.0625 in. Dia. x .2969 in. I.D.]
Legend + Included in seal repair kit listed on page 5.
NSS Not Sold Separately
* Covers are not included with Non-Set Compensator

Factory Pre-set Compensator Assemblies listed on page #10.

9
Model 70122

Factory Pre-set Compensator

Assemblies
Pre-set Pressure-Flow Compensator Assemblies
Non-Set Pre-set
Assembly Assembly Pump Rotation Pressure Setting Flow Setting
70422-HU 70422-AY-03 Lefthand (CCW) 210±3.5 bar [3050±50 lbf/in2] 13.8±0.7 bar [200±10 lbf/in2]
70422-HU 70422-BH-03 Lefthand (CCW) 191±2.1 bar [2770±30 lbf/in2] 15.2±0.7 bar [220±10 lbf/in2]
70422-HU 70422-BL-03 Lefthand (CCW) 183±3.5 bar [2650±50 lbf/in2] 25.2±1.8 bar [365±25 lbf/in2]
70422-HU 70422-DE-03 Lefthand (CCW) 193±3.5 bar [2800±50 lbf/in2] 13.8±0.7 bar [200±10 lbf/in2]
70422-HU 70422-DU-03 Lefthand (CCW) 176±3.5 bar [2550±50 lbf/in2] 19.0±1.8 bar [275±25 lbf/in2]
70422-HU 70422-EQ-03 Lefthand (CCW) 210±3.5 bar [3050±50 lbf/in2] 25.9±1.8 bar [375±25 lbf/in2]
70422-HU 70422-GD-03 Lefthand (CCW) 176±3.5 bar [2550±50 lbf/in2] 17.2±1.8 bar [250±25 lbf/in2]
70422-HU 70422-GN-03 Lefthand (CCW) 155±3.5 bar [2250±50 lbf/in2] 19.0±1.8 bar [275±25 lbf/in2]
70422-HU 70422-GP-03 Lefthand (CCW) 169±3.5 bar [2450±50 lbf/in2] 19.0±1.8 bar [275±25 lbf/in2]
70422-HU 70422-HL-03 Lefthand (CCW) 210±3.5 bar [3050±50 lbf/in2] 24.5±1.0 bar [355±15 lbf/in2]

70422-HY 70422-BM-01 Righthand (CW) 210±3.5 bar [3050±50 lbf/in2] 13.8±0.7 bar [200±10 lbf/in2]
70422-HY 70422-BU-01 Righthand (CW) 131±3.5 bar [1900±50 lbf/in2] 13.8±0.7 bar [200±10 lbf/in2]
70422-HY 70422-DB-01 Righthand (CW) 238±3.5 bar [3450±50 lbf/in2] 13.8±0.7 bar [200±10 lbf/in2]
70422-HY 70422-DJ-01 Righthand (CW) 210±3.5 bar [3050±50 lbf/in2] 25.9±1.8 bar [375±25 lbf/in2]
70422-HY 70422-DW-01 Righthand (CW) 155±3.5 bar [2250±50 lbf/in2] 13.8±0.7 bar [200±10 lbf/in2]
70422-HY 70422-ED-01 Righthand (CW) 169±3.5 bar [2450±50 lbf/in2] 19.0±1.8 bar [275±25 lbf/in2]
70422-HY 70422-ET-01 Righthand (CW) 176±3.5 bar [2550±50 lbf/in2] 13.8±0.7 bar [200±10 lbf/in2]
70422-HY 70422-EZ-01 Righthand (CW) 176±3.5 bar [2550±50 lbf/in2] 17.2±0.7 bar [250±10 lbf/in2]
70422-HY 70422-FB-01 Righthand (CW) 191±2.1 bar [2770±30 lbf/in2] 15.2±0.7 bar [220±10 lbf/in2]
70422-HY 70422-FL-01 Righthand (CW) 193±3.5 bar [2800±50 lbf/in2] 20.7±1.0 bar [300±15 lbf/in2]
70422-HY 70422-FR-01 Righthand (CW) 210±3.5 bar [3050±50 lbf/in2] 19.0±1.8 bar [275±25 lbf/in2]
70422-HY 70422-GA-01 Righthand (CW) 172±3.5 bar [2500±50 lbf/in2] 20.7±0.7 bar [300±10 lbf/in2]
70422-HY 70422-GR-01 Righthand (CW) 193±3.5 bar [2800±50 lbf/in2] 17.2±1.8 bar [250±25 lbf/in2]
70422-HY 70422-GU-01 Righthand (CW) 210±3.5 bar [3050±50 lbf/in2] 17.2±1.8 bar [250±25 lbf/in2]
70422-HY 70422-HK-01 Righthand (CW) 210±3.5 bar [3050±50 lbf/in2] 24.5±1.0 bar [355±15 lbf/in2]
70422-HY 70422-HM-01 Righthand (CW) 176±3.5 bar [2550±50 lbf/in2] 24.5±1.0 bar [355±15 lbf/in2]

Pre-set Pressure Compensator Assembly

Non-Set Pre-set
Assembly Assembly Pump Rotation Pressure Setting
70422-HR 70422-CA-04 Both 210±3.5 bar [3050±50 lbf/in2]
70422-HR 70422-CH-04 Both 162±3.5 bar [2350±50 lbf/in2]
70422-HR 70422-CK-04 Both 148±3.5 bar [2150±50 lbf/in2]
70422-HR 70422-CL-04 Both 141±3.5 bar [2050±50 lbf/in2]
70422-HR 70422-CR-04 Both 107±3.5 bar [1550±50 lbf/in2]
70422-HR 70422-DH-04 Both 176±1.8 bar [2550±25 lbf/in2]
70422-HR 70422-FG-04 Both 159±3.5 bar [2300±50 lbf/in2]
70422-HR 70422-GE-04 Both 169±1.8 bar [2450±25 lbf/in2]
70422-HR 70422-HB-04 Both 190±3.5 bar [2750±50 lbf/in2]
70422-HR 70422-HE-04 Both 110±3.5 bar [1600±50 lbf/in2]
70422-HR 70422-HN-04 Both 114±1.8 bar [1650±25 lbf/in2]

All left (CCW) or right (CW) directions

given are viewed from the input shaft end of the pump.

10
Model 70122

Item 5 - Rotating Kit Assembly

Item 5
Rotating Kit Assembly
Item Part No. Qty. Description
5 70111-695 1 Rotating Kit Assembly
5-1 NSS 9 Piston Assembly
5-2 NSS 1 Spider 5-9
5-3 NSS 1 Spider Pivot 5-7
5-4 NSS 1 Retainer
5-5 NSS 1 Piston Block
5-8
5-6 NSS 3 Pins
5-7
5-7 NSS 2 Washer 5 5-6
5-8 NSS 1 Spring 5-5
5-9 NSS 1 Retaining Ring
NSS - Not Sold Separately 5-4
5-2 5-3

5-1

11
Model 70122

Product Number

This list of product numbers is to aid in Item identification.

If your product number is not listed contact your Eaton representitive.

Model 70122, Lefthand Rotation (CCW)

Description of Part Number
Product Drive Shaft Backplate Assy. Housing Assy. Compensator Assy.
Number Item #1 Item #2 Item #3 Item #4

70122-LAE 70102-201 70120-311 70102-301 70422-CA-04

70122-LAF 70102-201 70120-311 70102-301 70422-AY-03
70122-LAN 70122-203 70120-311 70102-301 70422-CA-04
70122-LAP 70122-203 70120-311 70102-301 70422-AY-03
70122-LAW 70102-200 70120-314 70102-301 70422-AY-03
70122-LAY 70102-200 70120-314 70102-301 70422-CA-04
70122-LAZ 70122-203 70120-314 70102-301 70422-AY-03
70122-LBA 70122-203 70120-314 70120-314 70422-CA-04

Model 70122, Righthand Rotation (CW)

Description of Part Number
Product Drive Shaft Backplate Assy. Housing Assy. Compensator Assy.
Number Item #1 Item #2 Item #3 Item #4

70122-RAG 70102-201 70120-311 70120-314 70422-BM-01

70122-RAH 70102-201 70120-311 70120-314 70422-CA-04
70122-RAL 70122-203 70120-311 70120-314 70422-BM-01
70122-RAM 70122-203 70120-311 70120-314 70422-CA-04
70122-RAV 70102-200 70120-314 70120-314 70422-BM-01
70122-RAW 70102-200 70120-314 70120-314 70422-CA-04
70122-RAY 70122-203 70120-314 70120-314 70422-BM-01
70122-RAZ 70122-203 70120-314 70120-314 70422-CA-04

12
Model 70122

Repair Information
Cleanliness is extremely important when repairing should not be removed without compressing the
these pumps. Work in a clean area. Before spring.
disconnecting the lines clean port area of pump.
Disconnect hydraulic lines and remove pump The following parts will be needed to disassemble the
assembly from vehicle and plug ports. Thoroughly piston block:
clean the outside of pump. After cleaning, remove
2 ea. 5/16 l.D. x 15/16 O.D. flat washer,
port plugs and drain oil.
1 ea. 5/16 x 2-7/8 N.C. cap screw, and
Disassembly
ATTENTION: Removal of the adjusting screw covers 1 ea. 5/16 N.C. nut.
from cap may void the warranty on this assembly. Place one of the flat washers over the 5/16 x 2-7/
1 Clamp the end of the drive shaft in a protected 8 cap screw and place this through the center of the
jaw vise with the body of the pump up and remove piston block. Place the other washer over the cap
the four allen head screws (14) holding compensator screw and let it rest on the three pins. Screw the nut
on and compress the spring inside the piston block.
(4). Use a pair of snap ring pliers and remove the internal
snap ring (5-9). Remove the nut and bolt along with
2 Remove the compensator assembly (4), 0-ring the two washers (5-7), three pins (5-6), and the
(28), and gasket (24). internal pin keeper (5-4).
3 Remove the four cap screws (27) from the 9 To free shaft seal and shaft, remove retaining
backplate of the pump. ring (12).
4 Place a screw driver in slots provided between 10 Remove shaft (1) from housing (3) by tapping
housing and loosen backplate. Remove backplate (2) backplate end of shaft with a wooden or plastic
and gasket (21) from housing. mallet.
5 Remove the control piston (7) remaining on the 11 Remove shaft seal (17), washer (13), the two
backplate or in housing. Also remove plug (2-2) from retaining rings (10), the two thrust washers (16), and
backplate (2). bearing (15) from shaft.
6 To remove rotating assembly (5) from housing, 12 To remove the camplate (6) from the housing,
remove pump from vise and slide rotating assembly remove the two internal retaining rings (11) from the
off shaft. Caution: pistons may not come out with sides of the housing. Remove the two covers (20),
piston block. the two o-rings (26), the two inner races (19), and
7 Remove pistons (5-1), spider (5-2), and spider the bearings (25). The camplate can now be moved
pivot (5-3) from piston block (5-5). over to one side and removed. The two camplate
pivot bearings are a loose slip fit into the housing. Do
8 The piston block assembly (5-5) need not be not be concerned if they are not tight.
disassembled unless the internal pins (5-6) or spring
(5-8) are damaged. 13 Remove the spring collar (22) and spring (18).
Do not remove the button (23) and roll pin (9) unless
CAUTION: Use the following procedure if the spring they are worn or loose.
is to be removed from the piston block. The spring
(5-8) is highly compressed and the snap ring (5-9) 14 The pressure-flow compensator assembly (4)

13
Model 70122

Repair Information
may be disassembled for cleaning and inspection. end of the piston. The flat surface of the shoes
should be flat, and smooth. Do not lap piston shoes.
ATTENTION: Removal of the adjusting screw covers
from cap may void the warranty on this assembly. 5 Examine the spider (5-2). It should be flat, no
cracks, and no signs of wear in the pivot area.
15 Remove pressure adjustment cap (4-8) from
compensator housing (4-1). Pressure spring follower 6 Examine the pivot (5-3). It should be smooth and
(4-6) will remain in cap (4-8), pull follower from cap. show no signs of wear.
16 Remove flow adjustment cap (4-18) from 7 Inspect the camplate (6) for the condition of
compensator housing (4-1). Flow spring follower (4- finish of the polished shoe surface. It should show
16) will remain in cap (4-18). Pull follower from cap. no signs of scoring.
17 Remove springs (4-4 and 4-14) and spring pivots 8 Inspect shaft (1) for wear in bearing and spline
(4-3 and 4-13) from compensator housing. areas.
18 Remove plugs (4-19), pressure compensator 9 Inspect thrust bearing (15) and thrust washers
spool (4-2), and flow compensator spool (4-12) from (16) for wear.
compensator housing (4-1).
10 Inspect the needle bearing in the housing
19 The shaft seal, all 0-rings, and all gaskets should assembly (3). If the needles are free of excessive play
be removed and replaced with new items upon and remain in the bearing cage, there is no need to
reassembly. replace the housing.
11 Inspect the compensator springs (4-4 and 4-14)
for breakage or weakness.
Inspect Parts For Wear
12 Inspect the spools (4-2 and 4-12) for scoring.
1 Inspect the flat surface of the backplate (2), the
finish on the piston block side should be smooth and 13 It is not necessary to inspect the o-rings,
free of grooves. The piston guide should be tight in retaining rings, gaskets, or shaft seal as they should
the backplate. The needle bearing in the backplate be replaced as new items and are included in the seal
should be free of excessive play and remain in the repair kit available for this assembly.
bearing cage. If the backplate has any of the wear
characteristics outlined above, replace complete
backplate assembly.
Reassembly
2 Inspect the piston block (5). The surface that 1 Clean all parts in suitable solvent; lubricate all
contacts the backplate should be smooth and free of critical moving parts before reassembly.
grooves.
2 Install camplate control spring (18) and spring
3 The pistons (5-1) should move freely in the collar (22) in housing (3).
piston block bore. If they stick in the bore, examine
the bore for scoring or contamination. 3 Insert camplate (6) into housing (3). Insert
needle bearings (25) and bearing inner race (19) over
4 Examine the O.D. of the piston (5-1) for finish the camplate arms and slide into housing (3). The
condition. They should not show wear or deep numbered end of the bearing should face outward
scratches. The shoes should be a snug fit on the ball
14
Model 70122

Repair Information
and the chamfered l.D. of the race should face 14 Place new o-ring (4-19-1) on plug (4-19). Install
inward. plug assembly, flow compensator spool (4-12),
spring pivot (4-13), spring (4-14), flow spring
4 Install new 0-ring (26) around O.D. of camplate follower (4-16) with new o-ring (4-15), and flow
pivot bearing (25). Install trunnion covers (20) and adjustment cap (4-18) with new o-ring (4-17) into
secure with retaining rings (11). compensator housing (4-1). Torque plug (4-19) 8 to
5 Install retaining ring (10) on shaft (1). Install 11 N-m [6 to 8 lb-ft] and torque flow adjustment cap
thrust washer (16), thrust bearing (15), and second (4-18) 14 to 16 N-m [10 to 12 lb-ft ].
thrust washer (16). Secure with second retaining ring 15 Place new 0-ring (4-19-1) on plug (4-19). Install
(10). plug assembly, pressure compensator spool (4-2),
6 Install shaft (1) in housing (3) and install washer spring pivot (4-3), spring (4-4), pressure spring
(13), shaft seal (17), and retain with retaining ring follower (4-6) with new o-ring (4-5), and pressure
(12). Make sure retaining ring is seated in the adjustment cap (4-8) with new o-ring (4-7) into
groove. compensator housing (4-1). Torque plug (4-19) 8 to
10 N-m [6 to 8 lb-ft] and torque pressure adjustment
7 If piston block assembly was disassembled, cap (4-18) 47 to 54 N-m [35 to 40 lb-ft].
compress the pin keeper (5-4), and install in the
spline area of piston block. Install the three pins (5- 16 Install new gasket (24) and new o-ring (28), then
6) with the head end to the inside of the block and install compensator assembly (4),and retain with
install in the special grooves of the piston block four allen head cap screws (14) and torque to 14 to
spline. 16 N-m [10 to 12 lb-ft].

8 Install the washer (5-7), spring (5-8), and second 17 Plug ports to preserve cleanliness until
washer (5-7) in the piston block. Use the two 5/16 installation on vehicle. (Refer to start up procedures.)
l.D. washers and the 5/16 x 2-7/8 cap screw to
compress the spring and retain with retaining ring
(5-9). Remove the 5/16 x 2-7/8 cap screw and the
two washer.
9 Install the pivot (5-3), spider (5-2), and piston
assemblies (5-1) in the piston block. Install this
assembly in the housing assembly, the piston shoes
must be in contact with the camplate. Be sure all the
parts are in their proper position.
10 Clamp this assembly in a protected jaw vise with
the open end of the housing (3) up.
11 Install new gasket (21).
12 Install control piston (7), and plug (2-2) with new
o-ring onto backplate. Note roll pin (3-2) locations.
13 Install backplate (2) and retain with cap screws
(27). Torque to 23 to 27 N-m [17 to 20 lb-ft].
15
Model 70122

Start-up Procedure
When initially starting a rebuilt load sensing system, 5 Replace the coil wire or return the fuel flow to the
it is extremely important that the start-up procedure injectors and start the engine. Run at low idle speed
be followed. It prevents the chance of damaging the for one minute. The pump should immediately pick
pump which might occur if the system was not up oil and go into low pressure standby. If there is no
properly purged with oil before start-up. indication of fill in 30 seconds, stop engine and
1 After the pump has been properly installed onto determine the cause.
the machine and all hydraulic connections have been 6 After the pump has stabilized in low pressure
made, check all fittings to make sure that they are standby, operate the control valve and steering, if the
tight. system is equipped with one, to purge the system of
2 Fill the pump housing at least 1/2 full with air and to fill the cylinders with oil. Continue
system oil that has been filtered through a 10 micron operating the system slowly with no load until it
filter. responds fully.

3 Fill the reservoir with an approved oil that has 7 Check fluid level at the reservoir and refill if
been filtered through a 10 micron filter. Leave the necessary to the proper level at the reservoir and
filler cap loose as a means of air that is trapped in the refill if necessary to the proper level with an
system. approved filtered oil.

4 Note on gasoline or L.P. engines: remove the coil 8 Check all line connections for leaks tighten if
wire and turn the engine over for 15 seconds. Diesel necessary.
engines: shut off the fuel flow to the injectors and 9 The machine is now ready to be put into
turn the engine over for 15 seconds. This procedure operation.
enables the pump to pick-up the oil before start-up.
At this time disconnect the sensor line from the 10 Short hour filter changes are recommended for
pump compensator and pull one of the valve spools the first two changes after placing the machine back
while the engine is being turned over. This allows oil into operation. The first filter would be changed in 3-
to flow through the sensor line, thus, removing any 5 hours and the second at approximately 50 hours.
air in the sensor line. Reconnect the sensor line after Routine scheduled filter changes are recommended
a steady flow of oil is coming from the line. for maximum life of hydraulic system.

16
Model 70122

Fault - Logic
Troubleshooting
This fault - logic troubleshooting guide is a Explanatory
diagnostic aid in locating pump problems. Diagram Symptom:
Match the pump systems with the problem Action
statements and follow the action steps shown in the Step
box diagrams. This will give expedient aid in Comment Inspect
correcting minor problems eliminating unnecessary Number ?
machine down time. 1

Following the fault - logic diagrams are diagram Decision

Defective
action comments of the action steps shown in the
diagrams. Where applicable, the comment number of
Repair
the statement appears in the action block of the Solution
or
diagrams. Replace

Recommended Gauge Locations

Load Sensing Port
Test Port Tee in Line to Check
Inlet Vacuum - LH. Rotation Load Sensing Pressure
System Pressure - RH. Rotation

Test Port
System Pressure - LH. Rotation
Inlet Vacuum - RH. Rotation

Drain Port
Tee in Line to Check
Case Pressure

Gauges Recommended
Inlet vacuum gauge: 2 bar to 1 bar [30 PSI to 30 inHg]
System pressure gauge: 700 bar [10,000 PSI]
Case pressure gauge: 0 to 25 bar [0 to 300 PSI]

17
Model 70122

Fault - Logic
Troubleshooting

Symptom:
System will not Develop Proper Pressure or Flow

Check Check Inspect Inspect

Oil Level in OK Hyd. Fluid OK Inlet Screen OK Compensator
Reservoir Specs or Strainer Signal
1 2 3 4
Below Level Improper Clogged Low

Fill to Install Clean Inspect OK

Proper Proper or Signal
Level Fluid Replace Line
Defective

Repair
or
Replace

Inspect
Replace OK Pump
Pump Compensator
5
Defective

Repair
or
Replace

18
Model 70122

Fault - Logic
Troubleshooting

Symptom: Pump Noisy or Overheating

Check Check Inspect

Oil Level in OK Hyd. Fluid OK Inlet Screen OK Replace
Reservoir Specs or Strainer Pump
1 2 3
Below Level Improper Clogged

Fill to Install Clean

Proper Proper or
Level Fluid Replace

Diagram Action Step Comments

1. Check Oil Level in Reservoir: 4. Inspect Compensator Signal for:
A. Fill to proper level. A. Improper size or length of signal line.
B. Damaged or obstructed signal line
2. Check Hydraulic Fluid Specifications:
A. Consult owner/operators manual for the 5. *Inspect Pump Compensator for:
proper type fluid. A. Misadjusted pressure or flow setting.
B. Pressure or flow spool stuck open.
3. Inspect Inlet Screen or Strainer for: C. Pressure or flow spring weak or broken.
A. Suction screen or strainer plugged.
B. Suction line to small or too long
C. Suction line collapsed or plugged.

*Standard factory compensator pressure settings

A. Pressure compensator set at 3000 to 3100 PSI
(Optional settings of 1500 min. to 3100 max.
PSI)
B. Flow compensator set at 190 to 210 PSI
(Optional settings of 190 min. to 450 max. PSI)

19
Model 70122

Each order must include the following information.

1. Product and/or Part Number
2. Serial Number Code
3. Part Name
4. Quantity

ACCREDITED BY
THE DUTCH COUNCIL
FOR CERTIFICATION
Reg. No. 24

Eaton Corporation Eaton Ltd. Eaton GmbH ISO-9001 CERTIFICATED FIRM

DET NORSKE VERITAS INDUSTRY BV, THE NETHERLANDS

Hydraulics Division Hydraulics Division Hydraulics Products

Quality System Certified
15151 Hwy. 5 Glenrothes, Fife Am Schimmersfeld 7 Products in this catalog are manufactured
Eden Prairie, MN 55344 Scotland, KY7 4NW 40880 Ratingen, Germany in an ISO-9001-certified site.
Telephone 612/937-9800 Telephone 01-592-771-771 Telephone 02102-406-830
Fax 612/937-7130 Fax 01-592-773-184 Fax 02102-406-800

Copyright Eaton Corporation, 1991

Form No. 6-626 All Rights Reserved
July, 1991 Printed in USA

20
 ® No. 6-617
Eaton January 1998

Medium Duty Piston Pump

Parts and Repair

Information

Model 70523 or 70553, 0 -69 cm3/r [0-4.21 in3/r] Displacement

Pressure or Pressure-Flow Compensated Piston Pumps
Model 70523

Introduction
Table of Contents
Introduction ......................................................................................................... 2
Identification ........................................................................................................ 3
Tools Required .................................................................................................... 3
Parts Drawing ...................................................................................................... 4
Parts List ............................................................................................................. 5 - 12
Item 1 - Drive Shaft ID .................................................................................. 6
item 2 - Backplate Assembly ......................................................................... 7
Item 4 - Compensator Assembly and Parts List ............................................ 8 - 9
Factory Pre-set Compensator Assemblies ..................................................... 9
Item 3 - Housing Identification ...................................................................... 10
Item 5 - Rotating Kit ...................................................................................... 10
Mounting Kits ................................................................................................ 11
Product Number ............................................................................................ 12
Repair information ............................................................................................... 13 - 15
Disassembly .................................................................................................. 13
Inspection ..................................................................................................... 14
Reassembly ................................................................................................... 14 - 15
Start-up Procedure .............................................................................................. 16
Fault - Logic Troubleshooting .............................................................................. 17 - 19

Introduction
This manual provides service information for the Eaton Models 70523 Pressure or Pressure - Flow
Compensated Piston Pumps. Step by step instructions for the complete disassembly, inspection, and
reassembly of the pump are given. The following recommendations should be followed to insure successful
repairs.
Remove the pump from the application.
Cleanliness is extremely important.
Clean the port areas thoroughly before disconnecting the hydraulic lines.
Plug the pump ports and cover the open hydraulic lines immediately after they're disconnected.
Drain the oil and clean the exterior of the pump before making repairs.
Wash all metal parts in clean solvent.
Use compressed air to dry the parts. Do not wipe them dry with paper towels or cloth.
The compressed air should be filtered and moisture free.
Always use new seals when reassembling hydraulic pumps.
Lubricate the new rubber seals with a petroleum jelly (Vaseline) before installation.
Torque all bolts over gasketed joints, then repeat the torquing sequence to make-up for gasket
compression.
Verifying the accuracy of pump repairs on an authorized test stand is essential.
2
Model 70523

Identification and Tools Required

Identification Numbers - Pressure or Pressure-Flow Compensated Piston Pump
Stamped on each units mounting flange.

A - Product Number Description Single Pump - Product Number:

70523 = Single Piston Pump
70553 = Single Piston Pump, w/ Aux. Flange 70523 - RAA
B - Rotation
L - Left Hand (CCW) A
R - Right Hand (CW)
B C
C - Sequential Numbering

Serial Number Code:

B 93 01 31 JB
Revision level of parts list. Testers Initials

Last two digits of year built. Day of Month (two digits)

( 93 for 1993 etc.)
Month (two digits)

Serial Number Code prior to Jan., 1992:

1 B- 52-JB
Year Manufactured Testers Initials
(1 for 1991 etc.)
Week of Year
Change Code

Tools Required

• 3/8 Inch Socket • Internal Retaining Pliers (Straight .070 Tip)

• 9/16 Inch End Wrench • External Retaining Pliers (Straight .070 Tip)
• 1-1/2 Inch End Wrench • Regular or Locking Pliers
• 11/16 Inch End Wrench • Seal Driver or Similar Tool
• Rachet Wrench • Petroleum Jelly (Such as Vaseline)
• Torque Wrench (100 lb./ft.) • 1/2 inch I.D. x 1-3/8 inch O.D. flat washer (2 ea.)
• 3/16 Inch Hex Key (Allen) • 5/8 inch I.D. x 1-3/4 inch O.D. flat washer (1 ea.)
• 3/16 Inch Hex Key (Allen Socket) • 1/2 inch x 4-1/2 inch N.C. Cap screw (1 ea.)
• Soft Face Hammer • 1/2 inch N.C. Nut

3
Model 70523

Parts
Drawing
Pump drawn below is typical of a righthand (CW) rotation pump. 8 6
12 23 18
21
27 17
19
20
3

Serial code and

assembly number location

20
1 19
28 27
21
12
3-1

13
16
15
16
13
11 32 33
25
12
4
34
14
26
35
24
2 30
29
10
(Cover only)

9 29
30
7
22

All left (CCW) or right (CW) directions

given are viewed from the input shaft end of the pump.

4
Model 70523

Parts List
Item Part No. Qty. Description
1 ♦ 1 Drive Shaft (Identification drawing on page #6)
2 ♦ 1 Backplate Assembly (Identification drawing on page #7)
3 ♦ 1 Housing Assembly (Identification drawing on page #10)
3-1 77010-9 1 Bearing
4 ♦ 1 Compensator Assembly (Identification drawing on page #8 & 9)
5 ♦ 1 Rotating Kit Assembly (Parts list on page #10)
6 70523-605 1 Camplate
7 70523-423 1 Control Piston
8 16026-608 1 Roll Pin
9 16028-604 2 Dowel Pin
10 70523-618 2 Cover
11 16048-329 1 Washer
+ 12 16077-34 3 Retaining Ring
+ 13 16078-22 2 Retaining Ring
14 16147-412 4 Cap Screw
15 16241-2233 1 Thrust Bearing
16 16241-C2233 2 Thrust Bearing Race
17 17091-12 1 Spring
18 70420-35 1 Pivot Button
19 70500-100 2 Inner Race
20 70500-101 2 Thrust Bearing
21 70500-600 2 Trunnion Cover
+ 22 70500-604 1 Gasket
23 70523-400 1 Spring Collar
+ 24 70523-610 1 Gasket
+ 25 16232-22 1 Shaft Seal
25 16233-22 1 Shaft Seal, Drive (fluorocarbon rubber)
+ 26 16003-408-90 1 O-ring, 2.38 mm Dia. x 9.525 mm ID. [.0937 in. Dia. x .375 in. ID.]
+ 27 16004-3 2 O-ring, 3.175 mm Dia. x 47.625 mm ID. [.125 in. Dia. x 1.875 in. ID.]
27 16004-403 2 O-ring, 3.175 mm Dia. x 47.625 mm ID. [.125 in. Dia. x 1.875 in. ID.] (fluorocarbon)
28 16246-612 1 Key, Used on 31.75 [1.25] diameter shaft
29 16032-734 4 Cap Screw
30 16032-720 2 Cap Screw
32 70400-646 1 Mount Adapter, SAE "A" to "B" flange
33 16147-610 2 Cap Screw
34 16007-14 1 O-ring, (In K2 & K3 kit)
35 70411-617 1 Coupler, for 9 tooth spline
35 70411-604 1 Coupler, for 13 tooth spline

Mounting Kits (Drawings and parts list on Page #11)

K2 70442-929 1 Gear Pump Mounting Kit
K3 70142-915 1 Cover Plate Kit, (for "A" SAE flange)
K6 990596-000 1 Cover Plate Kit, (for "B" SAE flange)

Seal Repair Kit

• 70523-900 1 Seal Repair Kit

Legend ♦ Refer to specific item parts list.

+ Included in seal repair kits listed.

5
Model 70523

Item 1 - Drive Shaft Identification

Item 1
Drive Shaft Identification
Part Number Input Drive Output Drive

ate
ac kpl 9 Tooth
g eb
n
Fla External
70502-200, 14 Tooth olt
A
h 2-b
wit
ed
Us
ate
kpl
70502-202, eb
ac 13 Tooth
la ng
31.8 [1.25] Dia. Keyed lt BF External
2 -bo
w ith
ed
Us
te
pla
bac
k 9 Tooth
n ge
Fla External
70552-200, 14 Tooth olt
A
-b
h2
wit
ed
Us

70552-203, 14 Tooth

70552-209,
31.8 [1.25] Dia. Keyed

6
Model 70523

Item 2 - Backplate Assembly

2(a) 2(c)
Top Mounted Compensator Top Mounted Compensator
w/ "A" SAE Aux. Flange
2-2
(Loctited)

2-1

Lefthand Rotation Righthand Rotation

(CCW) (CW)

2(b) Rear Mounted Compensator

Lefthand Rotation Righthand Rotation

(CCW) (CW)

Item 2 - Parts List

Lefthand Righthand
Rotation Rotation
Item Part No. Part No. Qty. Description
2(a) 70523-301 70523-305 1 Opposite Side Porting, Top Mounted Compensator Backplate Assembly
2(b) ---- 70523-341 1 Opposite Side Porting, Rear Mounted Compensator Backplate Assembly
2(c) 70553-305 70553-303 1 Auxiliary 2-Bolt A Flange Series 82-2, Opposite Side Porting Backplate

2-1 16237-11816 1 Bearing

2-2 70523-614 1 Guide Pin

All left (CCW) or right (CW) directions

given are viewed from the input shaft end of the pump.

7
Model 70523

Item 4 - Compensator Assembly

Pressure-Flow Compensator Pressure Compensator

*4-11 *4-11 *4-11

Cover Cover Cover

non-set non-set non-set

4(a) 70523-FW 4(b) 70523-FU 4(c) 70523-FT
Lefthand (CCW) Pump Rotation Righthand (CW) Pump Rotation For Both Pump Rotations
*4-11, Cover not included with non-set compensator assy.

4-7 4-22-1
4-8 4-1
4-9
4-10
4-11 4-22
4-2
4-3
4-4
4-3
4-5 4-12
4-6
4-13
4-14
4-15
4-17 4-16

4-18
4-19
4-20
4-21
4-11

8
Model 70523

Item 4 - Compensator Parts List

Item 4 - Parts List (Refer to drawings)
Item Part No. Qty. Description
4(a) 70523-FW 1 Non-Set Pressure-Flow Compensator Assembly, Lefthand Rotation
4(b) 70523-FU 1 Non-Set Pressure-Flow Compensator Assembly, Righthand Rotation
4(c) 70523-FT 1 Non-Set Pressure Compensator Assembly
4-1 N/S 1 Compensator Body
4-2 N/S 1 Pressure Spool
4-3 70523-501 2 Spring Pivot
4-4 17122-8 1 Spring
+ 4-5 16003-7-90 1 O-ring, 1.588 mm Dia. x 8.26 mm I.D. [.0625 in. Dia. x .375 in. I.D.]
4-6 70500-628 1 Pressure Rod
+ 4-7 16015-24 1 O-ring, 2.38 mm Dia. x 31.75 mm I.D. [.0937 in. Dia. x 1.25 in. I.D.]
4-8 70500-627 1 Adjustment Cap, Pressure
4-9 16138-624 1 Set Screw
4-10 16024-6 1 Nut
4-11* 70523-618* 1or2 Cover*
4-12 N/S 1 Flow Spool
4-13 70500-605 1 Spring Pivot
4-14 17046-12 1 Spring
4-15 70500-629 1 Spring Pivot
+ 4-16 16003-1 1 O-ring, 1.59 mm Dia. x 3.175 mm I.D. [.0625 in. Dia. x .125 in. I.D.]
4-17 70500-631 1 Pressure Rod
+ 4-18 16133-6 1 O-ring, 1.98 mm Dia. x 11.89 mm I.D. [.078 in. Dia. x .468 in. I.D.]
4-19 70500-630 1 Adjustment Cap, Flow
4-20 16139-516 1 Set Screw
4-21 16024-5 1 Nut
4-22 16103-104 2 Plug Assembly
+ 4-22-1 16133-4 2 O-ring, 1.83 mm Dia. x 8.92 mm I.D. [.072 in. Dia. x .351 in. I.D.]
Legend + Included in seal repair kit listed on page 5.
NSS Not Sold Separately
* Covers are not included with Non-Set Compensator

Pre-set Pressure-Flow Compensator Assemblies

Non-Set Pre-set
Assembly Assembly Pump Rotation Pressure Setting Flow Setting
70523-FU 70523-DS-01 Righthand (CW) 176±3.5 bar [2550±50 lbf/in2] 13.8±0.7 bar [200±10 lbf/in2]
70523-FU 70523-EL-01 Righthand (CW) 193±3.5 bar [2800±50 lbf/in2] 19.3±0.7 bar [280±10 lbf/in2]
70523-FU 70523-EW-01 Righthand (CW) 155±3.5 bar [2250±50 lbf/in2] 5.68±1.2 bar [82.5±17.5 lbf/in2]
70523-FU 70523-FA-01 Righthand (CW) 193±3.5 bar [2800±50 lbf/in2] 13.8±0.7 bar [200±10 lbf/in2]
70523-FU 70523-FG-01 Righthand (CW) 210±3.5 bar [3050±50 lbf/in2] 13.8±0.7 bar [200±10 lbf/in2]
70523-FU 70523-FL-01 Righthand (CW) 193±3.5 bar [2800±50 lbf/in2] 15.8±0.7 bar [230±10 lbf/in2]

70523-FW 70523-FH-02 Lefthand (CCW) 210±3.5 bar [3050±50 lbf/in2] 13.8±0.7 bar [200±10 lbf/in2]
70523-FW 70523-FM-02 Lefthand (CCW) 134±3.5 bar [1950±50 lbf/in2] 21.7±0.7 bar [315±10 lbf/in2]

Pre-set Pressure Compensator Assembly

Non-Set Pre-set
Assembly Assembly Pump Rotation Pressure Setting
70523-FT 70523-FJ-03 Both 210±3.5 bar [3050±50 lbf/in2]

9
Model 70523

Item 3 - Housing Identification

Item 5 - Rotating Kit Assembly
"B" Drain Port
.875-14 SAE Straight Thd.
Item 3 Rightside (CW)
Housing Identification
Item Part No. Port Machined
3 70500-303 B Top of Pump
70500-311 A
70500-332 A, B

Leftside (CCW)

"A" Drain Port

.875-14 SAE Straight Thd.

Item 5
Rotating Kit Assembly
Item Part No. Qty. Description
5 70502-606 1 Rotating Kit Assembly
5-1 NSS 9 Piston Assembly
5-2 NSS 1 Spider
5-3 NSS 1 Spider Pivot 5-9
5-4 NSS 1 Retainer 5-8
5-5 NSS 1 Piston Block 5-7
5-6 NSS 3 Pins 5-6
5-7 NSS 1 Washer
5
5-8 NSS 1 Spring 5-5
5-9 NSS 1 Retaining Ring
NSS - Not Sold Separately 5-4
5-2 5-3

5-1

10
Model 70523

Mounting Kits
K2-3

K2-2
Kit 2, Gear Pump Mounting K2-1
(To Mount "A" SAE flanges)
Item Part No. Qty. Description
K2 70442-929 1 Gear Pump Mounting Kit
K2-1 16007-14 1 O-ring, 1.59 mm Dia. x 82.55 mm ID. [.0625 in. Dia. x 3.25 in. ID.]
K2-2 16048-113 2 Washer
K2-3 16032-612 2 Cap Screws

K3-3

K3-2
Kit 3 & 6, Cover Plates
For "A" SAE Flanges K3-1
Item Part No. Qty. Description
K3 70142-915 1 Cover Plate Kit for "A" SAE flange
K3-1 16007-14 1 O-ring, 1.59 mm Dia. x 82.55 mm ID. [.0625 in. Dia. x 3.25 in. ID.]
K3-2 70142-600 1 Cover Plate
K3-3 16032-610 2 Cap Screws

For "B" SAE Flanges (Not Pictured)

Item Part No. Qty. Description

K6 990596-000 1 Cover Plate Kit for "B" SAE flange

K6-1 102919-000 1 Gasket
K6-2 250073-000 1 Cover Plate
K6-3 95865-100 2 Cap Screws
K6-4 101896-050 2 Lock Washer

11
Model 70523

Product Number

This list of product numbers is to aid in Item identification.

If your product number is not listed contact your Eaton representitive.

Model 70523, Lefthand Rotation (CCW)

Description of Part Number
Product Drive Shaft Backplate Assy. Housing Assy. Compensator Assy.
Number Item #1 Item #2 Item #3 Item #4

70523-LAA 70502-200 70523-301 70500-303 70523-FJ-03

70523-LAB 70502-200 70523-301 70500-303 70523-FH-02
70523-LBF 70502-202 70523-301 70500-303 70523-FH-02
70523-LBG 70502-202 70523-301 70500-303 70523-FJ-03
70553-LAB 70552-200 70553-305 70500-303 70523-FH-02
70553-LAK 70552-209 70553-305 70500-303 70523-FH-02
70553-LAR 70552-203 70553-305 70500-303 70523-FH-02

Model 70523, Righthand Rotation (CW)

Description of Part Number
Product Drive Shaft Backplate Assy. Housing Assy. Compensator Assy.
Number Item #1 Item #2 Item #3 Item #4

70523-RAA 70502-200 70523-305 70500-303 70523-FJ-03

70523-RAB 70502-200 70523-305 70500-303 70523-FG-01
70523-RBE 70502-202 70523-305 70500-303 70523-FJ-03
70553-RAB 70552-200 70553-303 70500-303 70523-FG-01
70553-RAK 70552-209 70553-303 70500-303 70523-FG-01

All left (CCW) or right (CW) directions

given are viewed from the input shaft end of the pump.

12
Model 70523

Repair Information
Cleanliness is extremely important when repairing The following parts will be needed to disassemble the
these pumps. Work in a clean area. Before piston block:
disconnecting the lines clean port area of pump.
Disconnect hydraulic lines and remove pump 2 ea. 1/2 l.D. x 1-3/8 O.D. flat washer,
assembly from vehicle and plug ports. Thoroughly 1 ea. 5/8 x 1-3/4 flat washer, and
clean the outside of pump. After cleaning, remove 1 ea. 1/2 x 4-1/2 in. N.C. cap screw
port plugs and drain oil. 1 ea. 1/2 N.C. nut.
Place one of the flat washers over the 1/2 x 4-1/2
Disassembly in. cap screw and place this through the center of the
ATTENTION: Removal of the adjusting screw covers piston block. Place the 5/8 washer over the cap
from cap may void the warranty on this assembly. screw and let it rest on the three pins. Place the other
1/2 in. flat washer on the cap screw and screw the
1 Clamp the end of the drive shaft in a protected
nut on and compress the spring inside the piston
jaw vise with the body of the pump up and remove
block. Use a pair of snap ring pliers and remove the
the four allen head screws (14) holding compensator
internal snap ring (5-9). Remove the nut and bolt
(4).
along with the two washers (5-7), three pins (5-6),
2 Remove the compensator assembly (4), 0-ring and the internal pin keeper (5-4).
(26), and gasket (24).
9 To free shaft seal and shaft, remove retaining
3 Remove the six cap screws (29, four ea. and 30, ring (12).
two ea.) from the backplate of the pump.
10 Remove shaft (1) from housing (3) by tapping
4 Use a soft mallet to loosen backplate. Remove backplate end of shaft with a wooden or plastic
backplate (2) and gasket (22) from housing. mallet.

5 Remove the control piston (7) remaining on the 11 Remove shaft seal (25), washer (11), the two
backplate or in housing. retaining rings (13), the two thrust washers (16), and
bearing (15) from shaft.
6 To remove rotating assembly (5) from housing,
remove pump from vise and slide rotating assembly 12 To remove the camplate (6) from the housing,
off shaft. Caution: pistons may not come out with remove the two internal retaining rings (12) from the
piston block. sides of the housing. Remove the two covers (21),
the two o-rings (27), the two inner races (19), and
7 Remove pistons (5-1), spider (5-2), and spider the bearings (20). The camplate can now be moved
pivot (5-3) from piston block (5-5). over to one side and removed. The two camplate
8 The piston block assembly (5-5) need not be pivot bearings are a loose slip fit into the housing. Do
disassembled unless the internal pins (5-6) or spring not be concerned if they are not tight.
(5-8) are damaged. 13 Remove the spring collar (23) and spring (17).
CAUTION: Use the following procedure if the spring Do not remove the button (18) and roll pin (8) unless
is to be removed from the piston block. The spring they are worn or loose.
(5-8) is highly compressed and the snap ring (5-9) 14 The pressure-flow compensator assembly (4)
should not be removed without compressing the may be disassembled for cleaning and inspection.
spring.
ATTENTION: Removal of the adjusting screw covers

13
Model 70523

Repair Information
from cap may void the warranty on this assembly. 5 Examine the spider (5-2). It should be flat, no
cracks, and no signs of wear in the pivot area.
15 Remove pressure adjustment cap (4-8) from
compensator housing (4-1). Pressure rod (4-6) will 6 Examine the pivot (5-3). It should be smooth and
remain in cap (4-8), pull rod from cap. show no signs of wear.
16 Remove flow adjustment cap (4-19) from 7 Inspect the camplate (6) for the condition of
compensator housing (4-1). Pressure rod (4-17) will finish of the polished shoe surface. It should show
remain in cap (4-19). Pull rod from cap. no signs of scoring.
17 Remove springs (4-4 and 4-14) and spring pivots 8 Inspect shaft (1) for wear in bearing and spline
(4-3, 4-13 and 4-15) from compensator housing. areas.
18 Remove plugs (4-22), pressure compensator 9 Inspect thrust bearing (15) and thrust washers
spool (4-2), and flow compensator spool (4-12) from (16) for wear.
compensator housing (4-1).
10 Inspect the needle bearing in the housing
19 The shaft seal, all 0-rings, and all gaskets should assembly (3). If the needles are free of excessive play
be removed and replaced with new items upon and remain in the bearing cage, there is no need to
reassembly. replace the housing.
11 Inspect the compensator springs (4-4 and 4-14)
for breakage or weakness.
Inspect Parts For Wear
12 Inspect the spools (4-2 and 4-12) for scoring.
1 Inspect the flat surface of the backplate (2), the
finish on the piston block side should be smooth and 13 It is not necessary to inspect the o-rings,
free of grooves. The piston guide should be tight in retaining rings, gaskets, or shaft seal as they should
the backplate. The needle bearing in the backplate be replaced as new items and are included in the seal
should be free of excessive play and remain in the repair kit available for this assembly.
bearing cage. If the backplate has any of the wear
characteristics outlined above, replace complete
backplate assembly.
Reassembly
2 Inspect the piston block (5). The surface that 1 Clean all parts in suitable solvent; lubricate all
contacts the backplate should be smooth and free of critical moving parts before reassembly.
grooves.
2 Install camplate control spring (17) and spring
3 The pistons (5-1) should move freely in the collar (23) in housing (3).
piston block bore. If they stick in the bore, examine
the bore for scoring or contamination. 3 Insert camplate (6) into housing (3). Insert
needle bearings (20) and bearing inner race (19) over
4 Examine the O.D. of the piston (5-1) for finish the camplate arms and slide into housing (3). The
condition. They should not show wear or deep numbered end of the bearing should face outward
scratches. The shoes should be a snug fit on the ball and the chamfered l.D. of the race should face
end of the piston. The flat surface of the shoes inward.
should be flat, and smooth. Do not lap piston shoes.
4 Install new 0-ring (27) around O.D. of camplate

14
Model 70523

Repair Information
pivot bearing (20). Install trunnion covers (21) and 8 to 11 N-m [6 to 8 lb-ft ] and torque flow
secure with retaining rings (12). adjustment cap (4-19) 14 to 16 N-m [10 to 12 lb-ft ].
5 Install retaining ring (13) on shaft (1). Install 15 Place new o-ring (4-22-1) on plug (4-22). Install
thrust washer (16), thrust bearing (15), and second plug assembly, pressure compensator spool (4-2),
thrust washer (16). Secure with second retaining ring spring pivot (4-3), spring (4-4), second spring pivot
(13). (4-3), pressure rod (4-6) with new o-ring (4-5), and
pressure adjustment cap (4-8) with new o-ring (4-7)
6 Install shaft (1) in housing (3) and install washer into compensator housing (4-1). Torque plug (4-22)
(11), shaft seal (25), and retain with retaining ring 8 to 10 N-m [6 to 8 lb-ft ] and torque pressure
(12). Make sure retaining ring is seated in the adjustment cap (4-8) 47 to 54 N-m [35 to 40 lb-ft] .
groove.
16 Install new gasket (24) and new o-ring (26), then
7 If piston block assembly was disassembled, install compensator assembly (4),and retain with
compress the pin keeper (5-4), and install in the four allen head cap screws (14) and torque to 14 to
spline area of piston block. Install the three pins (5- 16 N-m [10 to 12 lb-ft].
6) into the special grooves of the piston block spline.
17 Plug ports to preserve cleanliness until
8 Install the washer (5-7), spring (5-8), into the installation on vehicle. (Refer to start up procedures.)
piston block. Use the three washers and the 1/2 x 4-
1/2 in. cap screw to compress the spring and retain
with retaining ring (5-9). Remove the cap screw and
the three washers.
9 Install the pivot (5-3), spider (5-2), and piston
assemblies (5-1) in the piston block. Install this
assembly in the housing assembly, the piston shoes
must be in contact with the camplate. Be sure all the
parts are in their proper position.
10 Clamp this assembly in a protected jaw vise with
the open end of the housing (3) up.
11 Install new gasket (22).
12 Install control piston (7), and plug (2-2) with new
o-ring onto backplate. Note roll pin (3-2) locations.
13 Install backplate (2) and retain with cap screws
(29 and 30). Torque to 47 to 54 N-m [35 to 40 lb-ft].
14 Place new o-ring (4-22-1) on plug (4-22). Install
plug assembly, flow compensator spool (4-12),
spring pivot (4-13), spring (4-14), spring pivot (4-
150, pressure rod (4-17) with new 0-ring (4-16), and
flow adjustment cap (4-19) with new 0-ring (4-18)
into compensator housing (4-1). Torque plug (4-22)

15
Model 70523

Start-up Procedure
When initially starting a rebuilt load sensing system, 5 Replace the coil wire or return the fuel flow to the
it is extremely important that the start-up procedure injectors and start the engine. Run at low idle speed
be followed. It prevents the chance of damaging the for one minute. The pump should immediately pick
pump which might occur if the system was not up oil and go into low pressure standby. If there is no
properly purged with oil before start-up. indication of fill in 30 seconds, stop engine and
determine the cause.
1 After the pump has been properly installed onto
the machine and all hydraulic connections have been 6 After the pump has stabilized in low pressure
made, check all fittings to make sure that they are standby, operate the control valve and steering, if the
tight. system is equipped with one, to purge the system of
air and to fill the cylinders with oil. Continue
2 Fill the pump housing at least 1/2 full with
operating the system slowly with no load until it
system oil that has been filtered through a 10 micron
responds fully.
filter.
7 Check fluid level at the reservoir and refill if
3 Fill the reservoir with an approved oil that has
necessary to the proper level at the reservoir and
been filtered through a 10 micron filter. Leave the
refill if necessary to the proper level with an
filler cap loose as a means of air that is trapped in the
approved filtered oil.
system.
8 Check all line connections for leaks tighten if
4 Note on gasoline or L.P. engines: remove the coil
necessary.
wire and turn the engine over for 15 seconds. Diesel
engines: shut off the fuel flow to the injectors and 9 The machine is now ready to be put into
turn the engine over for 15 seconds. This procedure operation.
enables the pump to pick-up the oil before start-up.
At this time disconnect the sensor line from the 10 Short hour filter changes are recommended for
pump compensator and pull one of the valve spools the first two changes after placing the machine back
while the engine is being turned over. This allows oil into operation. The first filter would be changed in 3-
to flow through the sensor line, thus, removing any 5 hours and the second at approximately 50 hours.
air in the sensor line. Reconnect the sensor line after Routine scheduled filter changes are recommended
a steady flow of oil is coming from the line. for maximum life of hydraulic system.

16
Model 70523

Fault - Logic
Troubleshooting
This fault - logic troubleshooting guide is a Explanatory
diagnostic aid in locating pump problems.
Diagram Symptom:
Match the pump systems with the problem Action
statements and follow the action steps shown in the Step
box diagrams. This will give expedient aid in Comment Inspect
correcting minor problems eliminating unnecessary Number ?
machine down time. 1

Following the fault - logic diagrams are diagram Decision

Defective
action comments of the action steps shown in the
diagrams. Where applicable, the comment number of
Repair
the statement appears in the action block of the Solution
or
diagrams. Replace

Recommended Gauge Locations

Load Sensing Port
Tee in Line to Check
Load Sensing Pressure

Install an in line
Test Port for:
System Pressure
and Inlet Vacuum

Drain Port
Tee in Line to Check
Case Pressure

Gauges Recommended
Inlet vacuum gauge: 2 bar to 1 bar [30 PSI to 30 inHg]
System pressure gauge: 700 bar [10,000 PSI]
Case pressure gauge: 0 to 25 bar [0 to 300 PSI]
17
Model 70523

Fault - Logic
Troubleshooting

Symptom:
System will not Develop Proper Pressure or Flow

Check Check Inspect Inspect

Oil Level in OK Hyd. Fluid OK Inlet Screen OK Compensator
Reservoir Specs or Strainer Signal
1 2 3 4
Below Level Improper Clogged Low

Fill to Install Clean Inspect OK

Proper Proper or Signal
Level Fluid Replace Line
Defective

Repair
or
Replace

Inspect
Replace OK Pump
Pump Compensator
5
Defective

Repair
or
Replace

18
Model 70523

Fault - Logic
Troubleshooting

Symptom: Pump Noisy or Overheating

Check Check Inspect

Oil Level in OK Hyd. Fluid OK Inlet Screen OK Replace
Reservoir Specs or Strainer Pump
1 2 3
Below Level Improper Clogged

Fill to Install Clean

Proper Proper or
Level Fluid Replace

Diagram Action Step Comments

1. Check Oil Level in Reservoir: 4. Inspect Compensator Signal for:
A. Fill to proper level. A. Improper size or length of signal line.
B. Damaged or obstructed signal line
2. Check Hydraulic Fluid Specifications:
A. Consult owner/operators manual for the 5. *Inspect Pump Compensator for:
proper type fluid. A. Misadjusted pressure or flow setting.
B. Pressure or flow spool stuck open.
3. Inspect Inlet Screen or Strainer for: C. Pressure or flow spring weak or broken.
A. Suction screen or strainer plugged.
B. Suction line to small or too long
C. Suction line collapsed or plugged.

*Standard factory compensator pressure settings

A. Pressure compensator set at 3000 to 3100 PSI
(Optional settings of 1500 min. to 3100 max.
PSI)
B. Flow compensator set at 190 to 210 PSI
(Optional settings of 190 min. to 450 max. PSI)

19
 ® No. 6-631
Eaton January 1998

Medium Duty Piston Pump

Parts and Repair

Information

Model 70422 or 70452

0 - 38 cm3/r [0 - 2.32 in3/r]
Displacement

Model 70423 or 70453

0 - 45 cm3/r [0 - 2.77 in3/r]
Displacement

Pressure or Pressure-Flow Compensated Piston Pumps

Model 70422 or 70423

Introduction
Table of Contents
Introduction ......................................................................................................... 2
Identification ........................................................................................................ 3
Tools Required .................................................................................................... 3
Parts Drawing ...................................................................................................... 4
Parts List ............................................................................................................. 5 - 15
Item 1 - Drive Shaft ID .................................................................................. 6
item 2 - Backplate Assembly ......................................................................... 7 - 8
Item 4 - Compensator Assembly and Parts List ............................................ 9 - 10
Factory Pre-set Compensator Assemblies ..................................................... 11
Item 3 - Housing Identification ...................................................................... 12
Item 5 - Rotating Kit ...................................................................................... 12
Mounting Kits ................................................................................................ 13
Product Number ............................................................................................ 14 - 15
Repair information ............................................................................................... 16 - 18
Disassembly .................................................................................................. 16
Inspection ..................................................................................................... 17
Reassembly ................................................................................................... 17 - 18
Start-up Procedure .............................................................................................. 19
Fault - Logic Troubleshooting .............................................................................. 20 - 23

Introduction
This manual provides service information for the Eaton Models 70422 or 70423 Pressure or Pressure - Flow
Compensated Piston Pumps. Step by step instructions for the complete disassembly, inspection, and
reassembly of the pump are given. The following recommendations should be followed to insure successful
repairs.
Remove the pump from the application.
Cleanliness is extremely important.
Clean the port areas thoroughly before disconnecting the hydraulic lines.
Plug the pump ports and cover the open hydraulic lines immediately after they're disconnected.
Drain the oil and clean the exterior of the pump before making repairs.
Wash all metal parts in clean solvent.
Use compressed air to dry the parts. Do not wipe them dry with paper towels or cloth.
The compressed air should be filtered and moisture free.
Always use new seals when reassembling hydraulic pumps.
Lubricate the new rubber seals with a petroleum jelly (Vaseline) before installation.
Torque all bolts over gasketed joints, then repeat the torquing sequence to make-up for gasket
compression.
Verifying the accuracy of pump repairs on an authorized test stand is essential.
2
Model 70422 or 70423

Identification and Tools Required

Identification Numbers - Pressure or Pressure-Flow Compensated Piston Pump
Stamped on each units mounting flange.

A - Product Number Description Single Pump - Product Number:

70422 = Single Piston Pump
70452 = Single Piston Pump, w/ Aux. Flange 70423 - RAA
70423 = Single Piston Pump
70453 = Single Piston Pump, w/ Aux. Flange A
B - Rotation
B C
L - Left Hand (CCW)
R - Right Hand (CW)
C - Sequential Numbering
Serial Number Code:
B 93 01 31 JB
Revision level of parts list. Testers Initials

Last two digits of year built. Day of Month (two digits)

( 93 for 1993 etc.)
Month (two digits)

Serial Number Code prior to Jan., 1992:

1 B- 52-JB
Year Manufactured Testers Initials
(1 for 1991 etc.)
Week of Year
Change Code

Tools Required

• 9/16 Inch Socket • Internal Retaining Pliers (Straight .070 Tip)

• 1-1/8 Inch End Wrench • External Retaining Pliers (Straight .070 Tip)
• 11/16 Inch End Wrench • Regular or Locking Pliers
• Rachet Wrench • Seal Driver or Similar Tool
• Torque Wrench (100 lb./ft.) • Petroleum Jelly (Such as Vaseline)
• 3/16 Inch Hex Key (Allen) • 3/8 inch I.D. x 1-1/8 inch O.D. flat washer (2 ea.)
• 3/16 Inch Hex Key (Allen Socket) • 3/8 inch x 3-1/4 inch N.C. Cap screw (1 ea.)
• Soft Face Hammer • 3/8 inch N.C. Nut

3
Model 70422 or 70423

Parts
Drawing
Pump drawn below is typical of a righthand (CW) rotation pump.
9 6
18 17
24
15 13
8
23
14 3

Serial code and

assembly number location
3-2

14
1 23
26 8
15
24
3-1

4 27

25
12
21
22
21
12
10 35
20 (Cover only)
11 7 28
19
16

5
2

All left (CCW) or right (CW) directions

given are viewed from the input shaft end of the pump.

4
Model 70422 or 70423

Parts List
Item Part No. Qty. Description
1 ♦ 1 Drive Shaft (Identification drawing on page #6)
2 ♦ 1 Backplate Assembly (Identification drawing on page #7 & 8)
3 ♦ 1 Housing Assembly (Identification drawing on page #12)
3-1 16238-11816 1 Bearing
3-2 16026-808 2 Roll Pin
4 ♦ 1 Compensator Assembly (Identification drawing on page #9, 10, & 11)
5 ♦ 1 Rotating Kit Assembly (Parts list on page #12)
6 70423-605 1 Camplate, 0 - 38 cm3/r [0 - 2.32 in3/r] Displacement
6 70423-610 1 Camplate, 0 - 45 cm3/r [0 - 2.77 in3/r] Displacement
7 70421-401 1 Control Piston, 0 - 38 cm3/r [0 - 2.32 in3/r] Displacement
7 70423-418 1 Control Piston, 0 - 45 cm3/r [0 - 2.77 in3/r] Displacement
+ 8 16015-27 2 O-ring, 2.38 mm Dia. x 36.51 mm ID. [.0937 in. Dia. x 1.4375 in. ID.]
9 16026-608 1 Roll Pin
10 16048-319 1 Washer
+ 11 16077-32 1 Retaining Ring
+ 12 16078-18 2 Retaining Ring
13 17091-14 1 Spring
14 70412-151 2 Thrust Bearing
15 70412-607 2 Trunnion Cover
+ 16 70412-626 1 Gasket
17 70420-35 1 Pivot Button
18 70420-59 1 Spring Collar
+ 19 70422-600 1 Gasket
+ 20 16253-18 1 Shaft Seal
20 16253-218 1 Shaft Seal, Drive (fluorocarbon rubber)
21 74308-100 2 Thrust Bearing Race
22 74308-101 1 Thrust Bearing
23 70402-100 2 Inner Race
+ 24 16077-26 2 Retaining Ring
+ 25 16003-405-90 1 O-ring, 1.59 mm Dia. x 6.35 mm ID. [.0625 in. Dia. x .25 in. ID.]
26 16246-516 1 Key, Used on 19.05 [.75] diameter shaft
26 24500-619 1 Key, Used on 22.2 [.875] diameter shaft
27 16148-412 4 Cap Screw
28 16032-612 4 Cap Screw
32 170142-600 1 Cover Plate (In K3 kit)
33 16032-610 2 Cap Screw, Cover Plate (In K3 kit)
+ 34 16007-14 1 O-ring, (In K2 & K3 kit)
35 70422-618 2 Cover

Mounting Kits (Drawings and parts list on Page #13)

K2 70442-929 1 Gear Pump Mounting Kit (for "A" SAE flange)
K3 70142-915 1 Cover Plate Kit, (for "A" SAE flange)
K6 990596-000 1 Cover Plate Kit, (for "B" SAE flange)
K7 70453-901 1 Gear Pump Mounting Kit, (for "B" SAE flange)

Seal Repair Kit

• 70422-915 1 Seal Repair Kit

Legend ♦ Refer to specific item parts list.

+ Included in seal repair kits listed.

5
Model 70422 or 70423

Item 1 - Drive Shaft Identification

Item 1
Drive Shaft Identification
Part Number Input Drive Output Drive

ate
ac kpl 9 Tooth
g eb
n
Fla Internal
70402-201, 13 Tooth olt
A
h 2-b
70402-207, 15 Tooth ed
wit
Us
te
pla
70402-204, b ack
lan
ge 41 Tooth
22.2 [.875] Dia. Keyed lt BF
h2
-bo External
wit
ed
Us
ate
kpl 9 Tooth
70442-235, eb
ac
la ng
25.4 [1.0] Dia. Keyed olt
AF Internal
h 2-b
wit
ed
Us
te
kpla
e bac 9 Tooth
70452-200, 13 Tooth la ng
lt AF Internal
-bo
70442-228, 15 Tooth it h2
edw
Us

70442-225, 13 Tooth
70442-246, 15 Tooth

70442-231,
22.2 [.875] Dia. Keyed

70402-206, 13 Tooth
w/ Retaining Ring Groove

6
Model 70422 or 70423

Item 2 - Model 70422 Backplate Assembly

(0 - 38 cm3/r [0 - 2.32 in3/r] Displacement)
2-2 2(a) 2(b)
2-2-1 Rear Porting Opposite Side Porting

2-3
(Loctited)

2-1

Lefthand Rotation Righthand Rotation Lefthand Rotation Righthand Rotation

(CCW) (CW) (CCW) (CW)

2(c)
Opposite Side Porting with 2-Bolt A Flange 2(d)
2-2 Opposite Side Porting with 2-Bolt B Flange
2-2-1

Lefthand Rotation Righthand Rotation Lefthand Rotation Righthand Rotation

(CCW) (CW) (CCW) (CW)

Item 2 - Model 70422 Parts List (0 - 38 cm3/r [0 - 2.32 in3/r] Displacement)

Lefthand Righthand
Rotation Rotation
Item Part No. Part No. Qty. Description
2(a) 70421-318 70421-343 1 Rear Porting Backplate Assembly
2(b) 70421-327 70421-334 1 Opposite Side Porting Backplate Assembly
2(c) 70452-302 70452-304 1 Auxiliary 2-Bolt A Flange Series 82-2, Opposite Side Porting Backplate
2(d) --- 70452-317 1 Auxiliary 2-Bolt B Flange Series 101-2, Opposite Side Porting Backplate

2-1 70421-150 1 Bearing

2-2 16103-103 2 Plug Assembly
+ 2-2-1 16133-3 2 O-ring, 1.59 mm Dia. x 7.54 mm I.D.
[.0625 in. Dia. x .2969 in. I.D.]
2-3 70422-428 1 Guide Pin
Legend + Included in seal repair kit listed on page 7.

All left (CCW) or right (CW) directions

given are viewed from the input shaft end of the pump.
7
Model 70422 or 70423

Item 2 - Model 70423 Backplate Assembly

(0 - 45 cm3/r [0 - 2.77 in3/r] Displacement)

2(a) 2(b)
2-2 Rear Porting Opposite Side Porting
2-2-1

2-3
(Loctited)

2-1

Lefthand Rotation Righthand Rotation Lefthand Rotation Righthand Rotation

(CCW) (CW) (CCW) (CW)

2(c)
Opposite Side Porting with 2-Bolt A Flange 2(d)
2-2 Opposite Side Porting with 2-Bolt B Flange
2-2-1

Lefthand Rotation Righthand Rotation Lefthand Rotation Righthand Rotation

(CCW) (CW) (CCW) (CW)

Item 2 - Model 70423 Parts List (0 - 45 cm3/r [0 - 2.77 in3/r] Displacement)

Lefthand Righthand
Rotation Rotation
Item Part No. Part No. Qty. Description
2(a) 70423-303 70423-301 1 Rear Porting Backplate Assembly
2(b) 70423-306 70423-312 1 Opposite Side Porting Backplate Assembly
2(c) 70453-301 70453-303 1 Auxiliary 2-Bolt A Flange Series 82-2, Opposite Side Porting Backplate
2(d) --- 70453-307 1 Auxiliary 2-Bolt B Flange Series 101-2, Opposite Side Porting Backplate

2-1 70421-150 1 Bearing

2-2 16103-103 2 Plug Assembly
+ 2-2-1 16133-3 2 O-ring, 1.59 mm Dia. x 7.54 mm I.D.
[.0625 in. Dia. x .2969 in. I.D.]
2-3 70422-428 1 Guide Pin
Legend + Included in seal repair kit listed on page 5.
All left (CCW) or right (CW) directions
given are viewed from the input shaft end of the pump.
8
Model 70422 or 70423

Item 4 - Compensator Assembly

Pressure-Flow Compensator Pressure Compensator

*4-11 *4-11 *4-11

Cover Cover Cover

non-set non-set non-set

4(a) 70422-HU 4(b) 70422-HY 4(c) 70422-HR
Lefthand (CCW) Pump Rotation Righthand (CW) Pump Rotation Fits Both Pump Rotations
(Righthand (CW) rotation shown)
*4-11, Cover not included with non-set compensator assy.

4-7
4-19
4-19-1 4-8

4-9
4-10
4-2 4-11
4-3
4-4
4-5
4-1 4-6
4-14
4-12 4-16
4-13
4-15

4-17
4-18
4-9
4-10
4-11
9
Model 70422 or 70423

Item 4 - Compensator Parts List

Item 4 - Parts List (Refer to drawings)
Item Part No. Qty. Description
4(a) 70422-HU 1 Non-Set Pressure-Flow Compensator Assembly, Lefthand Rotation
4(b) 70422-HY 1 Non-Set Pressure-Flow Compensator Assembly, Righthand Rotation
4(c) 70422-HR 1 Non-Set Pressure Compensator Assembly
4-1 N/S 1 Compensator Body
4-2 N/S 1 Pressure Spool
4-3 70422-405 1 Spring Pivot Cap
4-4 17063-11 1 Spring
+ 4-5 16003-11 1 O-ring, 2.38 mm Dia. x 14.29 mm I.D. [.0937 in. Dia. x .5625 in. I.D.]
4-6 70421-453 1 Pressure Spring Follower
+ 4-7 16015-18 1 O-ring, 2.38 mm Dia. x 22.23 mm I.D. [.0937 in. Dia. x .875 in. I.D.]
4-8 70422-606 1 Adjustment Cap, Pressure
4-9 70422-620 1or2 Set Screw
4-10 16024-4 1or2 Nut
4-11* 70422-618* 1or2 Cover*
4-12 N/S 1 Flow Spool
4-13 70411-411 1 Spring Pivot Cap
4-14 17029-5 1 Spring
+ 4-15 16003-4-90 1 O-ring, 1.59 mm Dia. x 5.55 mm I.D. [.0625 in. Dia. x .2187 in. I.D.]
4-16 70421-477 1 Flow Spring Follower
+ 4-17 16133-6 1 O-ring, 1.98 mm Dia. x 11.89 mm I.D. [.078 in. Dia. x .468 in. I.D.]
4-18 70422-602 1 Adjustment Cap Flow
4-19 16103-103 2 Plug Assembly
+ 4-19-1 16133-3 2 O-ring, 1.59 mm Dia. x 7.54 mm I.D. [.0625 in. Dia. x .2969 in. I.D.]
Legend + Included in seal repair kit listed on page 5.
NSS Not Sold Separately
* Covers are not included with Non-Set Compensator

Factory Pre-set Compensator Assemblies listed on page #11.

10
Model 70422 or 70423

Factory Pre-set Compensator

Assemblies
Pre-set Pressure-Flow Compensator Assemblies
Non-Set Pre-set
Assembly Assembly Pump Rotation Pressure Setting Flow Setting
70422-HU 70422-AY-03 Lefthand (CCW) 210±3.5 bar [3050±50 lbf/in2] 13.8±0.7 bar [200±10 lbf/in2]
70422-HU 70422-BH-03 Lefthand (CCW) 191±2.1 bar [2770±30 lbf/in2] 15.2±0.7 bar [220±10 lbf/in2]
70422-HU 70422-BL-03 Lefthand (CCW) 183±3.5 bar [2650±50 lbf/in2] 25.2±1.8 bar [365±25 lbf/in2]
70422-HU 70422-DE-03 Lefthand (CCW) 193±3.5 bar [2800±50 lbf/in2] 13.8±0.7 bar [200±10 lbf/in2]
70422-HU 70422-DU-03 Lefthand (CCW) 176±3.5 bar [2550±50 lbf/in2] 19.0±1.8 bar [275±25 lbf/in2]
70422-HU 70422-EQ-03 Lefthand (CCW) 210±3.5 bar [3050±50 lbf/in2] 25.9±1.8 bar [375±25 lbf/in2]
70422-HU 70422-GD-03 Lefthand (CCW) 176±3.5 bar [2550±50 lbf/in2] 17.2±1.8 bar [250±25 lbf/in2]
70422-HU 70422-GN-03 Lefthand (CCW) 155±3.5 bar [2250±50 lbf/in2] 19.0±1.8 bar [275±25 lbf/in2]
70422-HU 70422-GP-03 Lefthand (CCW) 169±3.5 bar [2450±50 lbf/in2] 19.0±1.8 bar [275±25 lbf/in2]
70422-HU 70422-HL-03 Lefthand (CCW) 210±3.5 bar [3050±50 lbf/in2] 24.5±1.0 bar [355±15 lbf/in2]

70422-HY 70422-BM-01 Righthand (CW) 210±3.5 bar [3050±50 lbf/in2] 13.8±0.7 bar [200±10 lbf/in2]
70422-HY 70422-BU-01 Righthand (CW) 131±3.5 bar [1900±50 lbf/in2] 13.8±0.7 bar [200±10 lbf/in2]
70422-HY 70422-DB-01 Righthand (CW) 238±3.5 bar [3450±50 lbf/in2] 13.8±0.7 bar [200±10 lbf/in2]
70422-HY 70422-DJ-01 Righthand (CW) 210±3.5 bar [3050±50 lbf/in2] 25.9±1.8 bar [375±25 lbf/in2]
70422-HY 70422-DW-01 Righthand (CW) 155±3.5 bar [2250±50 lbf/in2] 13.8±0.7 bar [200±10 lbf/in2]
70422-HY 70422-ED-01 Righthand (CW) 169±3.5 bar [2450±50 lbf/in2] 19.0±1.8 bar [275±25 lbf/in2]
70422-HY 70422-ET-01 Righthand (CW) 176±3.5 bar [2550±50 lbf/in2] 13.8±0.7 bar [200±10 lbf/in2]
70422-HY 70422-EZ-01 Righthand (CW) 176±3.5 bar [2550±50 lbf/in2] 17.2±0.7 bar [250±10 lbf/in2]
70422-HY 70422-FB-01 Righthand (CW) 191±2.1 bar [2770±30 lbf/in2] 15.2±0.7 bar [220±10 lbf/in2]
70422-HY 70422-FL-01 Righthand (CW) 193±3.5 bar [2800±50 lbf/in2] 20.7±1.0 bar [300±15 lbf/in2]
70422-HY 70422-FR-01 Righthand (CW) 210±3.5 bar [3050±50 lbf/in2] 19.0±1.8 bar [275±25 lbf/in2]
70422-HY 70422-GA-01 Righthand (CW) 172±3.5 bar [2500±50 lbf/in2] 20.7±0.7 bar [300±10 lbf/in2]
70422-HY 70422-GR-01 Righthand (CW) 193±3.5 bar [2800±50 lbf/in2] 17.2±1.8 bar [250±25 lbf/in2]
70422-HY 70422-GU-01 Righthand (CW) 210±3.5 bar [3050±50 lbf/in2] 17.2±1.8 bar [250±25 lbf/in2]
70422-HY 70422-HK-01 Righthand (CW) 210±3.5 bar [3050±50 lbf/in2] 24.5±1.0 bar [355±15 lbf/in2]
70422-HY 70422-HM-01 Righthand (CW) 176±3.5 bar [2550±50 lbf/in2] 24.5±1.0 bar [355±15 lbf/in2]

Pre-set Pressure Compensator Assembly

Non-Set Pre-set
Assembly Assembly Pump Rotation Pressure Setting
70422-HR 70422-CA-04 Both 210±3.5 bar [3050±50 lbf/in2]
70422-HR 70422-CH-04 Both 162±3.5 bar [2350±50 lbf/in2]
70422-HR 70422-CK-04 Both 148±3.5 bar [2150±50 lbf/in2]
70422-HR 70422-CL-04 Both 141±3.5 bar [2050±50 lbf/in2]
70422-HR 70422-CR-04 Both 107±3.5 bar [1550±50 lbf/in2]
70422-HR 70422-DH-04 Both 176±1.8 bar [2550±25 lbf/in2]
70422-HR 70422-FG-04 Both 159±3.5 bar [2300±50 lbf/in2]
70422-HR 70422-GE-04 Both 169±1.8 bar [2450±25 lbf/in2]
70422-HR 70422-HB-04 Both 190±3.5 bar [2750±50 lbf/in2]
70422-HR 70422-HE-04 Both 110±3.5 bar [1600±50 lbf/in2]
70422-HR 70422-HN-04 Both 114±1.8 bar [1650±25 lbf/in2]

11
Model 70422 or 70423

Item 3 - Housing Identification

"A" Drain Port
.5625-18 SAE Straight Thd.
"C" Drain Port

Item 3
Housing Identification
Item Part No. Port Machined
3 70402-304 A
70402-310 C
70402-336 B
70402-371 A, B

"B" Drain Port

.5625-18 SAE Straight Thd.

5-9
5-7
5-8
5-7
5 5-6
5-5

5-4
5-2 5-3

5-1
Item 5 - Rotating Kit Assembly
Item Part No. Qty. Description
5 70402-638 1 Model 70422 Rotating Kit Assembly
0 - 38 cm3/r [0 - 2.32 in3/r] Disp.
5 70423-617 1 Model 70423 Rotating Kit Assembly
0 - 45 cm3/r [0 - 2.77 in3/r] Disp.
5-1 NSS 9 Piston Assembly
5-2 NSS 1 Spider
5-3 NSS 1 Spider Pivot
5-4 NSS 1 Retainer
5-5 NSS 1 Piston Block
5-6 NSS 3 Pins
5-7 NSS 2 Washer
5-8 NSS 1 Spring
5-9 NSS 1 Retaining Ring
NSS - Not Sold Separately
12
Model 70422 or 70423

Mounting Kits

Kit 2, Gear Pump Mounting K2-3

(To Mount "A" SAE flanges)
Item Part No. Qty. Description
K2 70442-929 1 Gear Pump Mounting Kit
K2-1 16007-14 1 O-ring, 1.59 mm Dia. x 82.55 mm ID.
[.0625 in. Dia. x 3.25 in. ID.] K2-2
K2-2 16048-113 2 Washer
K2-3 16032-612 2 Cap Screws K2-1

Kit 7, Gear Pump Mounting

(To Mount "B" SAE flanges) K7-4
Item Part No. Qty. Description
K7 70423-901 1 Gear Pump Mounting Kit
K7-1 70423-615 1 Coupler, 41 Tooth
K7-2 16007-17 1 O-ring, 1.59 mm Dia. x 101.6 mm ID. K7-3
[.0625 in. Dia. x 4 in. ID.]
K7-3 16008-0 1 Lock Ring
K7-4 16032-814 2 Cap Screws K7-1
K7-2

K3-3
Kit 3 & 6, Cover Plates
For "A" SAE Flanges
Item Part No. Qty. Description
K3 70142-915 1 Cover Plate Kit for "A" SAE flange
K3-1 16007-14 1 O-ring, 1.59 mm Dia. x 82.55 mm ID.
[.0625 in. Dia. x 3.25 in. ID.]
K3-2 70142-600 1 Cover Plate K3-2
K3-3 16032-610 2 Cap Screws
K3-1
For "B" SAE Flanges (Not Pictured)
Item Part No. Qty. Description

K6 990596-000 1 Cover Plate Kit for "B" SAE flange

K6-1 102919-000 1 Gasket
K6-2 250073-000 1 Cover Plate
K6-3 95865-100 2 Cap Screws
K6-4 101896-050 2 Lock Washer

13
Model 70422 or 70423

Product Number

This list of product numbers is to aid in Item identification.

If your product number is not listed contact your Eaton representitive.

Model 70422, Lefthand Rotation (CCW)

Description of Part Number
Product Drive Shaft Backplate Assy. Housing Assy. Compensator Assy.
Number Item #1 Item #2 Item #3 Item #4

70422-LAG 70402-206 70421-318 70402-304 70422-CA-04

70422-LAH 70402-206 70421-318 70402-304 70422-AY-03
70422-LAY 70402-204 70421-318 70402-304 70422-CA-04
70422-LAZ 70402-204 70421-318 70402-304 70422-AY-03
70422-LBJ 70402-206 70421-327 70402-304 70422-AY-03
70422-LBK 70402-201 70421-327 70402-304 70422-CA-04
70422-LBL 70402-204 70421-327 70402-304 70422-AY-03
70422-LBM 70402-204 70421-327 70402-304 70422-CA-04
70452-LAG 70442-225 70452-302 70402-304 70422-AY-03
70452-LAJ 70442-225 70452-302 70402-304 70422-CA-04
70452-LAK 70442-231 70452-302 70402-304 70422-AY-03

Model 70422, Righthand Rotation (CW)

Description of Part Number
Product Drive Shaft Backplate Assy. Housing Assy. Compensator Assy.
Number Item #1 Item #2 Item #3 Item #4

70422-RAT 70402-206 70421-343 70402-304 70422-CA-04

70422-RAU 70402-206 70421-343 70402-304 70422-BM-01
70422-RCB 70402-204 70421-343 70402-304 70422-CA-04
70422-RCG 70402-204 70421-343 70402-304 70422-BM-01
70422-RDM 70402-201 70421-334 70402-304 70422-BM-01
70422-RDN 70402-206 70421-334 70402-304 70422-CA-04
70422-RDQ 70402-204 70421-334 70402-304 70422-CA-04
70452-RAG 70442-225 70452-304 70402-304 70422-BM-01
70452-RAJ 70442-231 70452-304 70402-304 70422-CA-04
70452-RAL 70442-231 70452-304 70402-304 70422-BM-01

All left (CCW) or right (CW) directions

given are viewed from the input shaft end of the pump.

14
Model 70422 or 70423

Product Number

This list of product numbers is to aid in Item identification.

If your product number is not listed contact your Eaton representitive.

Model 70423, Lefthand Rotation (CCW)

Description of Part Number
Product Drive Shaft Backplate Assy. Housing Assy. Compensator Assy.
Number Item #1 Item #2 Item #3 Item #4

70423-LBA 70402-204 70423-303 70402-304 70422-AY-03

70423-LBB 70402-201 70423-306 70402-304 70422-CA-04
70423-LBD 70402-204 70423-306 70402-304 70422-CA-04
70423-LBE 70402-204 70423-306 70402-304 70422-AY-03
70423-LBF 70402-201 70423-303 70402-304 70422-CA-04
70423-LBG 70402-201 70423-303 70402-304 70422-AY-03
70453-LAF 70402-207 70453-301 70402-304 70422-AY-03
70453-LAG 70402-207 70453-301 70402-304 70422-CA-04

Model 70423, Righthand Rotation (CW)

Description of Part Number
Product Drive Shaft Backplate Assy. Housing Assy. Compensator Assy.
Number Item #1 Item #2 Item #3 Item #4

70423-RBL 70402-204 70423-301 70402-304 70422-CA-04

70423-RBM 70402-204 70423-301 70402-304 70422-BM-01
70423-RBN 70402-201 70423-312 70402-304 70422-CA-04
70423-RBQ 70402-204 70423-312 70402-304 70422-CA-04
70423-RBS 70402-201 70423-301 70402-304 70422-CA-04
70423-RBT 70402-201 70423-301 70402-304 70422-BM-01
70453-RAG 70442-246 70453-303 70402-371 70422-BM-01
70453-RAJ 70442-235 70453-303 70402-371 70422-CA-04

All left (CCW) or right (CW) directions

given are viewed from the input shaft end of the pump.

15
Model 70422 or 70423

Repair Information
Cleanliness is extremely important when repairing should not be removed without compressing the
these pumps. Work in a clean area. Before spring.
disconnecting the lines clean port area of pump.
Disconnect hydraulic lines and remove pump The following parts will be needed to disassemble the
assembly from vehicle and plug ports. Thoroughly piston block:
clean the outside of pump. After cleaning, remove 2 ea. 3/8 l.D. x 1-1/8 O.D. flat washer,
port plugs and drain oil. 1 ea. 3/8 x 3-1/4 N.C. cap screw, and
1 ea. 3/8 N.C. nut.
Disassembly
ATTENTION: Removal of the adjusting screw covers Place one of the flat washers over the 5/16 cap
from cap may void the warranty on this assembly. screw and place this through the center of the piston
block. Place the other washer over the cap screw and
1 Clamp the end of the drive shaft in a protected let it rest on the three pins. Screw the nut on and
jaw vise with the body of the pump up and remove compress the spring inside the piston block. Use a
the four allen head screws (14) holding compensator pair of snap ring pliers and remove the internal snap
ring (5-9). Remove the nut and bolt along with the
(4).
two washers (5-7), three pins (5-6), and the internal
2 Remove the compensator assembly (4), 0-ring pin keeper (5-4).
(28), and gasket (24).
9 To free shaft seal and shaft, remove retaining
3 Remove the four cap screws (27) from the ring (12).
backplate of the pump.
10 Remove shaft (1) from housing (3) by tapping
4 Place a screw driver in slots provided between backplate end of shaft with a wooden or plastic
housing and loosen backplate. Remove backplate (2) mallet.
and gasket (21) from housing.
11 Remove shaft seal (17), washer (13), the two
5 Remove the control piston (7) remaining on the retaining rings (10), the two thrust washers (16), and
backplate or in housing. Also remove plug (2-2) from bearing (15) from shaft.
backplate (2).
12 To remove the camplate (6) from the housing,
6 To remove rotating assembly (5) from housing, remove the two internal retaining rings (11) from the
remove pump from vise and slide rotating assembly sides of the housing. Remove the two covers (20),
off shaft. Caution: pistons may not come out with the two o-rings (26), the two inner races (19), and
piston block. the bearings (25). The camplate can now be moved
over to one side and removed. The two camplate
7 Remove pistons (5-1), spider (5-2), and spider pivot bearings are a loose slip fit into the housing. Do
pivot (5-3) from piston block (5-5). not be concerned if they are not tight.
8 The piston block assembly (5-5) need not be 13 Remove the spring collar (22) and spring (18).
disassembled unless the internal pins (5-6) or spring Do not remove the button (23) and roll pin (9) unless
(5-8) are damaged. they are worn or loose.
CAUTION: Use the following procedure if the spring 14 The pressure-flow compensator assembly (4)
is to be removed from the piston block. The spring may be disassembled for cleaning and inspection.
(5-8) is highly compressed and the snap ring (5-9)

16
Model 70422 or 70423

Repair Information
ATTENTION: Removal of the adjusting screw covers 5 Examine the spider (5-2). It should be flat, no
from cap may void the warranty on this assembly. cracks, and no signs of wear in the pivot area.
15 Remove pressure adjustment cap (4-8) from 6 Examine the pivot (5-3). It should be smooth and
compensator housing (4-1). Pressure spring follower show no signs of wear.
(4-6) will remain in cap (4-8), pull follower from cap.
7 Inspect the camplate (6) for the condition of
16 Remove flow adjustment cap (4-18) from finish of the polished shoe surface. It should show
compensator housing (4-1). Flow spring follower (4- no signs of scoring.
16) will remain in cap (4-18). Pull follower from cap.
8 Inspect shaft (1) for wear in bearing and spline
17 Remove springs (4-4 and 4-14) and spring pivots areas.
(4-3 and 4-13) from compensator housing.
9 Inspect thrust bearing (15) and thrust washers
18 Remove plugs (4-19), pressure compensator (16) for wear.
spool (4-2), and flow compensator spool (4-12) from
compensator housing (4-1). 10 Inspect the needle bearing in the housing
assembly (3). If the needles are free of excessive play
19 The shaft seal, all 0-rings, and all gaskets should and remain in the bearing cage, there is no need to
be removed and replaced with new items upon replace the housing.
reassembly.
11 Inspect the compensator springs (4-4 and 4-14)
for breakage or weakness.

Inspect Parts For Wear 12 Inspect the spools (4-2 and 4-12) for scoring.
1 Inspect the flat surface of the backplate (2), the 13 It is not necessary to inspect the o-rings,
finish on the piston block side should be smooth and retaining rings, gaskets, or shaft seal as they should
free of grooves. The piston guide should be tight in be replaced as new items and are included in the seal
the backplate. The needle bearing in the backplate repair kit available for this assembly.
should be free of excessive play and remain in the
bearing cage. If the backplate has any of the wear
characteristics outlined above, replace complete
backplate assembly. Reassembly
1 Clean all parts in suitable solvent; lubricate all
2 Inspect the piston block (5). The surface that critical moving parts before reassembly.
contacts the backplate should be smooth and free of
grooves. 2 Install camplate control spring (18) and spring
collar (22) in housing (3).
3 The pistons (5-1) should move freely in the
piston block bore. If they stick in the bore, examine 3 Insert camplate (6) into housing (3). Insert
the bore for scoring or contamination. needle bearings (25) and bearing inner race (19) over
the camplate arms and slide into housing (3). The
4 Examine the O.D. of the piston (5-1) for finish numbered end of the bearing should face outward
condition. They should not show wear or deep and the chamfered l.D. of the race should face
scratches. The shoes should be a snug fit on the ball inward.
end of the piston. The flat surface of the shoes
should be flat, and smooth. Do not lap piston shoes. 4 Install new 0-ring (26) around O.D. of camplate

17
Model 70422 or 70423

Repair Information
pivot bearing (25). Install trunnion covers (20) and adjustment cap (4-18) with new o-ring (4-17) into
secure with retaining rings (11). compensator housing (4-1). Torque plug (4-19) 8 to
11 N-m [6 to 8 lb-ft] and torque flow adjustment cap
5 Install retaining ring (10) on shaft (1). Install (4-18) 14 to 16 N-m [10 to 12 lb-ft ].
thrust washer (16), thrust bearing (15), and second
thrust washer (16). Secure with second retaining ring 15 Place new 0-ring (4-19-1) on plug (4-19). Install
(10). plug assembly, pressure compensator spool (4-2),
spring pivot (4-3), spring (4-4), pressure spring
6 Install shaft (1) in housing (3) and install washer follower (4-6) with new o-ring (4-5), and pressure
(13), shaft seal (17), and retain with retaining ring adjustment cap (4-8) with new o-ring (4-7) into
(12). Make sure retaining ring is seated in the compensator housing (4-1). Torque plug (4-19) 8 to
groove. 10 N-m [6 to 8 lb-ft] and torque pressure adjustment
7 If piston block assembly was disassembled, cap (4-18) 47 to 54 N-m [35 to 40 lb-ft].
compress the pin keeper (5-4), and install in the 16 Install new gasket (24) and new o-ring (28), then
spline area of piston block. Install the three pins (5- install compensator assembly (4),and retain with
6) with the head end to the inside of the block and four allen head cap screws (14) and torque to 14 to
install in the special grooves of the piston block 16 N-m [10 to 12 lb-ft].
spline.
17 Plug ports to preserve cleanliness until
8 Install the washer (5-7), spring (5-8), and second installation on vehicle. (Refer to start up procedures.)
washer (5-7) in the piston block. Use the two 3/8 l.D.
washers and the 3/8 x 3-1/4 cap screw to compress
the spring and retain with retaining ring (5-9).
Remove the 3/8 cap screw and the two washers.
9 Install the pivot (5-3), spider (5-2), and piston
assemblies (5-1) in the piston block. Install this
assembly in the housing assembly, the piston shoes
must be in contact with the camplate. Be sure all the
parts are in their proper position.
10 Clamp this assembly in a protected jaw vise with
the open end of the housing (3) up.
11 Install new gasket (21).
12 Install control piston (7), and plug (2-2) with new
o-ring onto backplate. Note roll pin (3-2) locations.
13 Install backplate (2) and retain with cap screws
(27). Torque to 37 to 42 N-m [27 to 31 lb-ft].
14 Place new o-ring (4-19-1) on plug (4-19). Install
plug assembly, flow compensator spool (4-12),
spring pivot (4-13), spring (4-14), flow spring
follower (4-16) with new o-ring (4-15), and flow

18
Model 70422 or 70423

Start - up Procedure
When initially starting a rebuilt load sensing system, 5 Replace the coil wire or return the fuel flow to the
it is extremely important that the start-up procedure injectors and start the engine. Run at low idle speed
be followed. It prevents the chance of damaging the for one minute. The pump should immediately pick
pump which might occur if the system was not up oil and go into low pressure standby. If there is no
properly purged with oil before start-up. indication of fill in 30 seconds, stop engine and
determine the cause.
1 After the pump has been properly installed onto
the machine and all hydraulic connections have been 6 After the pump has stabilized in low pressure
made, check all fittings to make sure that they are standby, operate the control valve and steering, if the
tight. system is equipped with one, to purge the system of
air and to fill the cylinders with oil. Continue
2 Fill the pump housing at least 1/2 full with operating the system slowly with no load until it
system oil that has been filtered through a 10 micron responds fully.
filter.
7 Check fluid level at the reservoir and refill if
3 Fill the reservoir with an approved oil that has necessary to the proper level at the reservoir and
been filtered through a 10 micron filter. Leave the refill if necessary to the proper level with an
filler cap loose as a means of air that is trapped in the approved filtered oil.
system.
8 Check all line connections for leaks tighten if
4 Note on gasoline or L.P. engines: remove the coil necessary.
wire and turn the engine over for 15 seconds. Diesel
engines: shut off the fuel flow to the injectors and 9 The machine is now ready to be put into
turn the engine over for 15 seconds. This procedure operation.
enables the pump to pick-up the oil before start-up.
At this time disconnect the sensor line from the 10 Short hour filter changes are recommended for
pump compensator and pull one of the valve spools the first two changes after placing the machine back
while the engine is being turned over. This allows oil into operation. The first filter would be changed in 3-
to flow through the sensor line, thus, removing any 5 hours and the second at approximately 50 hours.
air in the sensor line. Reconnect the sensor line after Routine scheduled filter changes are recommended
a steady flow of oil is coming from the line. for maximum life of hydraulic system.

19
Model 70422 or 70423

Fault - Logic
Troubleshooting
This fault - logic troubleshooting guide is a
diagnostic aid in locating pump problems.
Symptom:
Match the pump systems with the problem Action
statements and follow the action steps shown in the Step
box diagrams. This will give expedient aid in Comment Inspect
correcting minor problems eliminating unnecessary Number ?
machine down time. 1

Following the fault - logic diagrams are diagram Decision

Defective
action comments of the action steps shown in the
diagrams. Where applicable, the comment number of
Repair
the statement appears in the action block of the Solution
or
diagrams. Replace

Recommended Gauge Locations Load Sensing Port

Load Sensing Port Tee in Line to Check
Test Port Tee in Line to Check Test Port Load Sensing Pressure
Inlet Vacuum - LH. Rotation Load Sensing Pressure System Pressure - RH. Rotation
System Pressure - RH. Rotation System Pressure - LH. Rotation

Test Port
System Pressure - LH. Rotation
Inlet Vacuum - RH. Rotation

Drain Port
Tee in Line to Check
Case Pressure
Drain Port
Tee in Line to Check Tee in Line to suction port for inlet
Case Pressure vacuum test. Suction port is the
Model 70422 Model 70423 largest port.
0 - 38 cm3/r [0 - 2.32 in3/r] Displacement 0 - 45 cm3/r [0 - 2.77 in3/r] Displacement

Gauges Recommended
Inlet vacuum gauge: 2 bar to 1 bar [30 PSI to 30 inHg]
System pressure gauge: 700 bar [10,000 PSI]
Case pressure gauge: 0 to 25 bar [0 to 300 PSI]

20
Model 70422 or 70423

Fault - Logic
Troubleshooting

Symptom:
System will not Develop Proper Pressure or Flow

Check Check Inspect Inspect

Oil Level in OK Hyd. Fluid OK Inlet Screen OK Compensator
Reservoir Specs or Strainer Signal
1 2 3 4
Below Level Improper Clogged Low

Fill to Install Clean Inspect OK

Proper Proper or Signal
Level Fluid Replace Line
Defective

Repair
or
Replace

Inspect
Replace OK Pump
Pump Compensator
5
Defective

Repair
or
Replace

21
Model 70422 or 70423

Fault - Logic
Troubleshooting

Symptom: Pump Noisy or Overheating

Check Check Inspect

Oil Level in OK Hyd. Fluid OK Inlet Screen OK Replace
Reservoir Specs or Strainer Pump
1 2 3
Below Level Improper Clogged

Fill to Install Clean

Proper Proper or
Level Fluid Replace

22
Model 70422 or 70423

Fault - Logic
Troubleshooting
Diagram Action Step Comments
1. Check Oil Level in Reservoir:
A. Fill to proper level.
2. Check Hydraulic Fluid Specifications:
A. Consult owner/operators manual for the proper
type fluid.
3. Inspect Inlet Screen or Strainer for:
A. Suction screen or strainer plugged.
B. Suction line to small or too long
C. Suction line collapsed or plugged.
4. Inspect Compensator Signal for:
A. Improper size or length of signal line.
B. Damaged or obstructed signal line
5. *Inspect Pump Compensator for:
A. Misadjusted pressure or flow setting.
B. Pressure or flow spool stuck open.
C. Pressure or flow spring weak or broken.

*Standard factory compensator pressure settings

A. Pressure compensator set at 3000 to 3100 PSI
(Optional settings of 1500 min. to 3100 max. PSI)
B. Flow compensator set at 190 to 210 PSI
(Optional settings of 190 min. to 450 max. PSI)

23
 Each order must include the following information.
1. Product and/or Part Number
2. Serial Number Code
3. Part Name
4. Quantity

ACCREDITED BY
THE DUTCH COUNCIL
FOR CERTIFICATION
Reg. No. 24

Eaton Corporation Eaton Ltd. Eaton GmbH ISO-9001 CERTIFICATED FIRM

DET NORSKE VERITAS INDUSTRY BV, THE NETHERLANDS

Hydraulics Division Hydraulics Division Hydraulics Products

Quality System Certified
15151 Hwy. 5 Glenrothes, Fife Am Schimmersfeld 7 Products in this catalog are manufactured
Eden Prairie, MN 55344 Scotland, KY7 4NW 40880 Ratingen, Germany in an ISO-9001-certified site.
Telephone 612/937-9800 Telephone 01-592-771-771 Telephone 02102-406-830
Fax 612/937-7130 Fax 01-592-773-184 Fax 02102-406-800

Copyright Eaton Corporation, 1993

Form No. 6-631 All Rights Reserved
May, 1993 Printed in USA