MAKING MODERN LIVING POSSIBLE

Service Manual

Series 45 J Frame
Open Circuit Axial Piston Pumps

powersolutions.danfoss.com
Service Manual Series 45 J Frame Open Circuit Axial Piston Pumps

History of Revisions Table of Revisions

Date Page Changed Rev.

September 2013 - Danfoss conversion AI

December 2012 9 Displacement limiter is available - change to max. pressure AH
October 2012 various add electric controls AG
November 2010 last new last page AF
February 2010 last Fix Osaka address AE
July 2009 20 Pressure change - PC adjustment specs AD
March 2007 21 typo in illustration - set screw torque is 7.5-10.8Nm AB
[5.5 -8 lbf•ft]
May 2005 - First edition A

Front cover illustrations: F301320_S45-FRAME-J

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Service Manual Series 45 J Frame Open Circuit Axial Piston Pumps

Contents

Introduction Overview....................................................................................................................................................................................... 5
Safety precautions..................................................................................................................................................................... 5
Unintended machine movement.................................................................................................................................. 5
Flammable cleaning solvents.......................................................................................................................................... 5
Fluid under pressure........................................................................................................................................................... 5
Personal safety...................................................................................................................................................................... 5
Symbols used in Danfoss literature..................................................................................................................................... 6
General description................................................................................................................................................................... 7
System circuit.............................................................................................................................................................................. 8

Technical Specifications General specifications.............................................................................................................................................................. 9

Hydraulic parameters............................................................................................................................................................. 10
Inlet pressure....................................................................................................................................................................... 10
Pressure compensator valve setting........................................................................................................................... 10
Case pressure....................................................................................................................................................................... 10
Hydraulic fluid .................................................................................................................................................................... 10
Fluid viscosity...................................................................................................................................................................... 10
Filtration ............................................................................................................................................................................... 10

Features Auxiliary mounting pads....................................................................................................................................................... 11

Input shafts................................................................................................................................................................................ 11
Control options......................................................................................................................................................................... 12
PC control............................................................................................................................................................................. 12
LS control.............................................................................................................................................................................. 13
Electric Proportional Controls....................................................................................................................................... 14
Electric On/Off Controls................................................................................................................................................... 14

Pressure Measurement Required tools........................................................................................................................................................................... 15

Port locations and gauge installation.............................................................................................................................. 15

Initial Start-up Procedures General......................................................................................................................................................................................... 16

Start-up procedure.................................................................................................................................................................. 16

Fluid and Filter Maintenance Recommendations.................................................................................................................................................................. 17

Troubleshooting Excessive noise and/or vibration........................................................................................................................................ 18

Actuator response is sluggish............................................................................................................................................. 18
System operating hot............................................................................................................................................................. 19
Low pump output flow.......................................................................................................................................................... 19
Pressure or flow instability................................................................................................................................................... 19
Pressure or flow instability (continued)........................................................................................................................... 20
System pressure not reaching PC setting....................................................................................................................... 20
High inlet vacuum................................................................................................................................................................... 20

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Contents (continued)

Adjustments PC control.................................................................................................................................................................................... 21
LS control....................................................................................................................................................................................22

Minor repair Shaft seal replacement..........................................................................................................................................................23

Auxiliary pads............................................................................................................................................................................ 24
LS and PC Controls..................................................................................................................................................................25
LS and PC Controls (continued).......................................................................................................................................... 26
Electric Controls........................................................................................................................................................................ 27
Servo Control Orifice.............................................................................................................................................................. 29
Plug and fitting sizes and torques.....................................................................................................................................30

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Service Manual Series 45 J Frame Open Circuit Axial Piston Pumps

Introduction

Overview This manual includes information for the installation, maintenance, and minor repair of the Series 45
frame J open circuit axial piston pumps. The manual includes a description of the units and their
individual components, troubleshooting information, and minor repair procedures. Performing
installation, maintenance, and minor repair of Series 45 J frame axial piston pumps according to the
procedures in this manual will not affect your warranty.

Performing minor repairs requires the unit to be removed from the vehicle/machine. Thoroughly
clean the unit before beginning maintenance, or repair activities. Since dirt and contamination are
the greatest enemies of any type of hydraulic equipment, follow cleanliness requirements strictly.
This is especially important when changing the system filter and when removing hoses or plumbing.

A worldwide network of Danfoss Authorized Service Centers (ASCs) is available for major repairs.
Major repairs require the removal of the unit’s endcap, which voids the warranty unless done by an
ASC. Danfoss ASCs are trained by the factory and certified on a regular basis. You can locate your
nearest ASC using the distributor locator at www.Danfoss.com

Safety Precautions Always consider safety precautions before beginning a service procedure. Protect yourself and others
from injury. Take these general precautions whenever servicing a hydraulic system.

Unintended machine movement

 Warning
Unintended movement of the machine or mechanism may cause injury to the technician or
bystanders. To protect against unintended movement, secure the machine or disable / disconnect
the mechanism while servicing.

Flammable cleaning solvents

 Warning
Some cleaning solvents are flammable. To avoid possible fire, do not use cleaning solvents in an area
where a source of ignition may be present.

Fluid under pressure

 Warning
Escaping hydraulic fluid under pressure can have sufficient force to penetrate your skin causing
serious injury and/or infection. This fluid may also be hot enough to cause burns. Use caution when
dealing with hydraulic fluid under pressure. Relieve pressure in the system before removing hoses,
fittings, gauges, or components. Never use your hand or any other body part to check for leaks in a
pressurized line. Seek medical attention immediately if you are cut by hydraulic fluid.

Personal safety
 Warning
Protect yourself from injury. Use proper safety equipment, including safety glasses, at all times.

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Service Manual Series 45 J Frame Open Circuit Axial Piston Pumps

Introduction (continued)

Symbols used in Danfoss These symbols are in the illustrations and text of this manual. They communicate helpful information
Literature at the point where it is most useful to the reader.

In most instances, the appearance of the symbol itself denotes its meaning. The legend below defines
the symbol and explains its purpose.

 WARNING may result in injury  Tip, helpful suggestion

 CAUTION may result in damage to  Lubricate with hydraulic fluid

product or property
 Apply grease/petroleum jelly
 Reusable part
 Apply locking compound
 Non-reusable part, use a new part
 Inspect for wear or damage
 Non-removable item
 Clean area or part
 Option – either part may exist
 Be careful not to scratch or damage
 Superseded – parts are not
interchangeable  Note correct orientation

 Measurement required  Mark orientation for reinstallation

 Flatness specification  Torque specification

 Parallelism specification  Press in – press fit

 External hex head  Pull out with tool – press fit

 Internal hex head  Cover splines with installation sleeve

 Torx head  Pressure measurement/gauge

location or specification
 O-ring boss port

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Introduction (continued)

General Description Danfoss Series 45 J frame open circuit piston pumps convert input torque into hydraulic power.
Rotational force is transmitted through the input shaft to the cylinder block. The input shaft is
supported by tapered roller bearings at the front and rear of the pump and is splined into the cylinder
block . A lip-seal at the front end of the pump prevents leakage where the shaft exits the pump
housing. The spinning cylinder block contains nine reciprocating pistons. Each piston has a brass
slipper connected at one end by a ball joint. The slippers are held to the swashplate by the spring
retainer and block spring. The block spring also holds the cylinder block to the valve plate. The
reciprocating movement of the pistons occurs as the slippers slide against the inclined swashplate
during rotation. Via the valve plate, one half of the cylinder block is connected to pump inlet and the
other half to pump outlet. As each piston cycles in and out of its bore, fluid is drawn from the inlet
and displaced to the outlet thereby imparting power into the system circuit. A small amount of fluid is
allowed to “leak” from the cylinder block/valve plate and slipper/swashplate interfaces for lubrication
and cooling. Case drain ports are provided to return this fluid to the reservoir.

The volume of fluid displaced into the system circuit is controlled by the angle of the swashplate. The
swashplate is forced into an inclined position (into stroke) by the bias spring. The servo piston
opposes the action of the bias spring forcing the swashplate out of stroke when hydraulic pressure in
the control circuit rises above the spring force.

The pump control, by varying the pressure at the servo piston, controls the displacement of fluid in
the system circuit. Controls designed for Pressure Compensation (PC) or Load Sensing (LS) are
available. For a detailed description of control operation, refer to Control options, operation, page 12.

Pump and control sectional view

LS control
(attached to endcap)
LS spool LS adjustment

PC adjustment

PC spool
Bias spring
Servo piston
Slipper
Piston

Shaft seal
Valve plate
Input shaft
Block
spring

Tapered
Tapered
roller
roller
bearing
bearing

Cylinder block
Swashplate
Slipper retainer
P104 362

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Introduction (continued)

System Circuit The pump receives fluid directly from the reservoir through the inlet line. A screen placed in the inlet
protects the pump from large contaminants. The output of the pump is directed to a PVG-32
multi-section load sensing directional control valve which directs fluid to the actuators in the system.
Fluid returning from the system is cooled by a heat exchanger and cleaned by a filter before returning
to the reservoir.

The speed of the actuators in the system depends on the volume of fluid being provided by the
pump. The operating pressure varies depending on actuator load, but is limited to an adjustable
maximum setting by the PC section of the pump control and by a system relief valve integrated into
the side module of the PVG valve.

The position of the PVG valve sets the demand for flow in the system and communicates this to the
pump control by means of a hydraulic signal (load sense signal). The pump will provide as much flow
to the system as it demands1 while limiting the maximum pressure. Therefore flow and pressure in the
system are compensated to meet requirements.

Pictorial circuit diagram

J Frame Series 45 Double-acting cylinder

open circuit axial
piston pump with
load sensing control
PVG 32
multi-section
load
sensing
control
valve

Bi-directional
gear motor

System pressure

Servo pressure
Heat exchanger
Filter Actuator pressure
Reservoir
Load sense pressure

Actuator return

Suction / case drain /

P104 366E system return

1
Full available flow is a function of pump displacement, operating speed, and efficiency. Refer to Series 45 Axial
Piston Open Circuit Pumps Technical Information, 520L0676 for details.

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Technical Specifications

General Specifications Features and options Model

Feature Unit J45B J51B J60B J65C J75C
Maximum Displacement cm³ [in³] 45 [2.75]] 51 [3.11] 60 [3.66] 65 [3.97] 75 [4.58]
l/min 126.0 137.7 156.0 162.6 180
Flow at rated speed (theoretical) [US gal/min] [33.3] [36.4] [41.2] [42.9] [47.5]
Input torque at maximum N•m/bar 0.716 0.811 0.956 1.035 1.193
displacement (theoretical) [lbf•in/1000 psi] [436.9] [495.1] [583.6] [631.4] [728.1]
Mass moment of inertia of kg•m² 0.00455 0.00455 0.00455 0.00433 0.00433
internal rotating components [slug•ft²] [0.00336] [0.00336] [0.00336] [0.00319] [0.00319]
Axial ports kg [lb] 23.13 [51]
Weight
Radial ports 26.65 [58.8]
Rotation Clockwise, Counterclockwise
Mounting 2 bolt SAE-B, 4 bolt SAE-C
Auxiliary mounting SAE-A, SAE-B, SAE-BB, SAE-C
System ports (type) SAE R-ring boss. 4-bolt split flange
System ports (location) Axial, Radial
Control types PC, Remote PC, LS, LS with internal bleed
Splined 13-tooth, 14-tooth, 15-tooth
Shafts
Tapered Ø 31.75 mm [1.25 in], 1:8 taper
Straight Ø 31.75 mm [1.25 in]
Displacement limiters Available

Ratings Model
Rating Units J45B J51B J60B J65C J75C
minimum 500 500 500 500 500
Input speed¹ continuous min-1 (rpm) 2800 2700 2600 2500 2400
maximum 3360 3240 3120 3000 2880
Working 310 310 310 260 260
maximum bar [psi]
pressure [4495] [4495] [4495] [3770] [3770]
226 226 226 226 226
External moment (Me) N•m [lbf•in]
External shaft [2000] [2000] [2000] [2000] [2000]
loads 2200 2200 2200 2200 2200
Thrust in (Tin), out (Tout) N [lbf] [495] [495] [495] [495] [495]
at 140 bar [2030 psi] 29 712 29 712 29 712 10 755 10 755
at 210 bar [3045 psi] 6834 6834 6834 2474 2474
Bearing life B10 hours
at 260 bar [3770 psi] 3151 3151 3151 — —
at 310 bar [4495 psi] 1666 1666 1666 — —
Vibratory SAE-C: 1500 [14 000], SAE-B: 735 [6500]
Mounting flange (continuous) N•m [lbf•in]
load moments
Shock (max) SAE-C: 5600 [50 000], SAE-B: 2600 [23 000]
1. Continuous input speeds are valid at 1 bar absolute [0 in HG vac] inlet pressure. Maximum input speeds require changing
the inlet pressure or reducing pump displacement.

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Service Manual Series 45 J Frame Open Circuit Axial Piston Pumps

Technical specifications

Hydraulic Parameters Inlet pressure

Minimum pressure, continuous = 0.8 bar absolute [6.7 inches Hg vac.]
(at reduced maximum pump speed)

Minimum pressure, cold start = 0.5 bar absolute [15.1 inches Hg vac.]

Pressure compensator valve setting

Minimum: 100 bar [1450 psi]
Maximum: 310 bar [3770 psi] (depending on displacement)

For more information, refer to Series 45 J Frame Axial Piston Open Circuit Pumps Technical Information,
520L0676.

Case pressure
Maximum continuous: 0.5 bar [7 psi] Above inlet
Intermittent: 2 bar [29 psi] Cold start

Hydraulic fluid
Refer to Danfoss publication Fluids and Filtration BLN-9887 or 520L0463. For information on
biodegradable fluids refer to Biodegradable Hydraulic Fluids, 520L0465. See Fluid and filter
maintenance, page 17 for recommended fluid and filter change intervals.

Temperature range1
Intermittent (cold start): - 40° C [- 40° F]
Continuous: 82° C [180° F]
Maximum2: 104° C [220° F]

Fluid viscosity
Viscosity limits
Rating mm2/s (cSt)
[SUS]
minimum 9 [58]
ν continuous
maximum 110 [500]
minimum 6.4 [47]
ν intermittent maximum 1000 [4700]
(cold start)

Filtration
Required cleanliness level: ISO 4406 Class 18/13 or better. Refer to Danfoss publications Fluids and
Filtration BLN-9887 or 520L0463 and Design Guidelines for Selecting and Maintaining the Required
Hydraulic Fluid Cleanliness 520L0465. See Fluid and filter maintenance, page 17 for recommended fluid
and filter change intervals.

1
Hydraulic fluid viscosity must be maintained within the prescribed limits.
2
As measured at the hottest point in the system, e.g. drain line.

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Features

Auxiliary Mounting Pads Auxiliary mounting pads are available for all Auxiliary pad options
radial ported Series 45 pumps. These pads are
typically used for mounting auxiliary hydraulic
pumps.

Since the auxiliary pad operates under case

pressure, an O-ring must be used to seal the
auxiliary pump mounting flange to the pad. The
drive coupling is lubricated by oil from the main
pump case. For details refer to Series 45 J Frame
Axial Piston Open Circuit Pumps Technical
Information, 520L0676.

P104 361

Input Shafts Series 45 J frame pumps are available with a variety of splined, straight keyed, and tapered end shafts.
For information on shafts refer to Series 45 J Frame Axial Piston Open Circuit Pumps Technical
Information, 520L0676.

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Service Manual Series 45 J Frame Open Circuit Axial Piston Pumps

Features (continued)

Control Options The Series 45 Frames J have three possible general control options, a Load Sensing (LS) control with
Pressure Compensator (PC), a PC only control, or an electric control.

Operation Cross-section pump

The bias spring (1) pushes against the servo
2 1 3
piston (2) which pulls the swashplate (3) to max
angle causing the pump to stroke. Internal
pressure on the servo piston acts against the bias
spring to reduce the swashplate angle causing
the pump to destroke. Swashplate angle
determines pump outlet flow. The pump control,
depending on conditions in the system circuit,
sets swashplate angle by metering system
pressure to the servo piston.

P104 360
Bias spring and servo piston set swashplate position

PC control Cross-section PC control

The PC control design maintains a constant
pressure in the hydraulic circuit as flow varies. 4
The PC control modulates pump flow accordingly
to maintain system pressure at the PC setting as
the PC adjusting plug (4) and spring (5) defines.

When system pressure, acting on the non-spring 6 5

end of the PC spool (6), overcomes the force of P104 049
the PC spring, the spool shifts porting system
PC spool shifts to port system pressure to servo
pressure to the servo piston and the swashplate
piston
angle decreases. When system pressure drops
below the PC setting, the PC spring shifts the
spool in the opposite direction connecting the
servo piston to pump case and the swashplate
angle increases. The swashplate is maintained at
whatever angle is required to keep system
pressure at the PC setting.

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Features (continued)

Control Options LS control Typical load-sensing control valve

(continued) The LS control design matches pump flow with Load Return
system demand. The LS control senses the flow pressure pressure
demand of the system as a pressure drop across
the External Control Valve (ECV). As the ECV Tank
opens and closes, the pressure delta across the
valve changes. When opening, the delta
decreases. When closing, the delta increases. The
LS control then increases or decreases pump
flow to the system until the pressure delta
becomes equal to the LS setting as defined by
the LS adjusting plug (7) and spring (8). Load sense System
pressure pressure P101 665E

Pressure drop across external control valve defines

system demand

The LS control consists of two spool valves that Cross-section LS control

connect the servo piston either to pump case or
system pressure. The PC spool (6) controls the Spring Spring
pressure-compensating function of the control guide LS spring
as previously described. The LS spool (9) controls Spool LS adjusting
Plug
the load-sensing function. The PC spool has plug
priority over the LS spool. PC adjusting
Plug plug
Through internal porting, system pressure Spring
(upstream of ECV) is applied to the non-spring Spool Spring (PC heavy)
end of the LS spool, and through hydraulic line guide P104 051
connected at port X, LS pressure (downstream of
ECV) is applied to the spring end. This
arrangement allows the LS spool to act on the LS spool shifts to port system pressure to servo
delta between system pressure and LS pressure. piston
The LS spring sets the threshold of operation (LS
setting).

Because the swashplate is biased to maximum angle, the pump attempts to deliver full flow to the
hydraulic system. When the flow being delivered exceeds demand, the pressure delta across the ECV
is great enough to overcome spring force and shift the LS spool porting system pressure to the servo
piston. The pump de-strokes reducing flow until the delta across the ECV becomes equal to the LS
setting. When flow being delivered is less than demand, the delta across the ECV drops below the LS
setting and the LS spring shifts the spool connecting the servo piston to pump case. The pump
strokes increasing flow until the delta across the ECV becomes equal to the LS setting.

When the external control valve is placed in neutral, it connects the LS signal line to drain. With no LS
pressure acting on the non-spring end of the LS spool, the pump adjusts stroke to whatever position
necessary to maintain system pressure at the LS setting. The pump is now in standby mode.

Because of the series arrangement of the LS and PC spools, the PC spool will override the LS spool. If
at any time system pressure reaches the PC setting, the PC spool will shift blocking the passage that
connects the LS spool with the servo piston and porting system pressure to the servo piston causing
the pump to destroke.

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Service Manual Series 45 J Frame Open Circuit Axial Piston Pumps

Features (continued)

Control Options Electric Proportional Controls

(continued)
PLUS+1 Compliance
All Series 45 Electric controls have met and
passed the Danfoss PLUS+1 compliance standard
testing, and as such, this Series 45 control is
PLUS+1 compliant. PLUS+1 compliance blocks
are available on the Danfoss website, within the
PLUS+1 Guide section.





Electric Proportional Control Principle

The Electric Proportional Control consists of a
proportional solenoid integrated into a Remote
Pressure Compensated control. This control
allows the pump to be operated at any pressure
limit between the Load Sense and Pressure
Compensation settings by varying the current
sent to the solenoid.

Electric On/Off Controls

PLUS+1 Compliance
All Series 45 Electric controls have met and
passed the Danfoss PLUS+1 compliance standard
testing, and as such, this Series 45 control is
PLUS+1 compliant. PLUS+1 compliance blocks
are available on the Danfoss website, within the
PLUS+1 Guide section.





Electric On-Off Control Principle

The Electric On/Off Control consists of an On/Off
solenoid integrated into a Remote Pressure
Compensated control. This control allows the
pump to be operated at either the Load Sense
pressure setting when “On”, or the Pressure
Compensation pressure setting when “Off”.

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Pressure measurement

Required Tools The service procedures described in this manual can be performed using common mechanic’s hand
tools. Special tools, if required are shown. Calibrate pressure gauges frequently to ensure accuracy.
Use snubbers to protect gauges.

Port Locations and Gauge The illustration below shows gauge port locations. Recommended pressure gauges and fittings are in
Installation the table.
Gauge and port information
Port Purpose Range of gauge Fitting
M1 System pressure 0-300 bar [0-5000 psi] 9/16 - 18 O-ring fitting
L1, L2 Case drain port 0-10 bar [0-100 psi] 7/8 - 14 O-ring fitting
7/16 - 20 O-ring fitting
X LS signal 0-300 bar [0-5000 psi] (tee into LS signal line)

Gauge port locations

M1
L1 L2
P104 364

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Install Start-up Procedures

General Follow this procedure when starting-up a new Series 45 installation or when restarting an
installation in which the pump has been removed.

Warning
Unintended movement of the machine or mechanism may cause injury to the technician or
bystanders. To protect against unintended movement, secure the machine or disable / disconnect
the mechanism while servicing.

Prior to installing the pump, inspect for damage incurred during shipping. Make certain all system
components (reservoir, hoses, valves, fittings, heat exchanger, etc.) are clean prior to filling with
fluid.

Start-up Procedure
1. Connect the pump to the prime mover. Ensure that pump shaft is properly aligned with the shaft
 Caution of the prime mover. 
Incorrect shaft alignment may
result in damage to drive 2. Fill the reservoir with recommended hydraulic fluid. Always filter fluid through a 10 micron filter
shaft, bearings, or seal which pouring into the reservoir. Never reuse hydraulic fluid.
can cause external oil leakage.
3. Fill the main pump housing with clean hydraulic fluid. Pour filtered oil directly into the upper most
case drain port.

4. Fill the inlet line leading from the pump to the reservoir. Check the inlet line for properly tightened
fittings and be certain it is free of restrictions and air leaks.

5. To ensure the pump stays filled with oil, install the case drain line in the upper most case drain
port.

6. Install a gauge at port M1 to monitor system pressure during start up.

Follow recommendations in the vehicle/machine operator’s manual for prime mover start up
procedures.

7. While watching the pressure gauge installed at M1, jog the prime mover or run at the lowest
possible speed until system pressure builds to normal levels (minimum 11 bar [160 psi]). Once
system pressure is established, increase to full operating speed. If system pressure is not
maintained, shut down the prime mover, determine cause, and take corrective action. Refer to
Troubleshooting, page 18.

8. Operate the hydraulic system for at least fifteen minutes under light load conditions.

9. Check and adjust control settings as necessary after installation. Refer to Adjustments, page 21.

10. Shut down the prime mover and remove the pressure gauge. Replace plug at port M1.

11. Check the fluid level in the reservoir; add clean filtered fluid if necessary.

12. The pump is now ready for operation.

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Fluid and Filter Maintenance

Recommendations To ensure optimum life of Series 45 products, perform regular maintenance of the fluid and filter.
Contaminated fluid is the main cause of unit failure. Take care to maintain fluid cleanliness when
servicing.

Check the reservoir daily for proper fluid level, the presence of water, and rancid fluid odor. Water in
the fluid may be noted by a cloudy or milky appearance or free water in the bottom of the reservoir.
Rancid odor indicates the fluid has been exposed to excessive heat. Change the fluid immediately if
these conditions occur. Correct the problem immediately.

Change the fluid and filter per the Fluid and filter change interval
vehicle/machine manufacturer’s Reservoir type Maximum change interval
recommendations or at these intervals:
Sealed 2000 hours
Change the fluid more frequently if it becomes Breather 500 hours
contaminated with foreign matter (dirt, water,
grease, etc.) or if the fluid is subjected to
temperature levels greater that the recommended maximum.

Dispose of used hydraulic fluid properly. Never reuse hydraulic fluid.

Change filters whenever the fluid is changed or when the filter indicator shows that it is necessary to
change the filter. Replace all fluid lost during filter change.

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Service Manual Series 45 J Frame Open Circuit Axial Piston Pumps

Troubleshooting

Excessive Noise and/or Item Description Action

Vibration Insufficient hydraulic fluid causes
Check fluid level in reservoir. Fill the reservoir to proper level.
cavitation.
Air in system causes noisy, erratic Purge air and tighten fittings. Check
Check for air in system. control. inlet for leaks.
Improper inlet conditions cause Correct pump inlet pressure /
Check pump inlet pressure/vacuum. erratic behavior and low output vacuum conditions. Refer to
flow. Hydraulic parameters, page 10.
A loose or incorrect shaft coupling Repair or replace coupling and
Inspect shaft couplings. causes excessive noise and/or ensure that correct coupling is
vibration. used.
Misaligned shafts create excessive
Check shaft alignment. Correct shaft misalignment.
noise and/or vibration.
Allow system to warm up before
Hydraulic fluid viscosity above operating, or use fluid with the
acceptable limits or low fluid appropriate viscosity grade for
Hydraulic fluid viscosity above temperature will not allow the expected operating temperatures.
acceptable limits. pump to fill or control to operate See Hydraulic Fluids and Lubricants
properly. Technical Information Manual,
520L0463.

Actuator Response is Item Description Action

Sluggish Adjust external relief valve setting
following manufacturer’s
Check external system relief valve Low external relief valve setting recommendations. External relief
setting. slows down system. setting must be above PC setting to
operate properly.
Low PC setting prevents the pump Adjust PC and LS setting. Refer to
Check PC and LS control setting. from achieving full stroke. Low LS Adjustments, page 21
setting limits output flow.
Incorrect LS signal will not allow Inspect system to ensure that
Check LS control signal pressures. pump to operate correctly. proper LS signal transmit to pump.
Worn internal parts don’t allow the Refer to Authorized Service Center
Internal system leaks. pump to operate properly. for required repair.
Allow system to warm up before
Hydraulic fluid viscosity above operation or sue fluid with the
acceptable limits or low fluid appropriate viscosity grade for
Hydraulic fluid viscosity above temperature will not allow the expected operating temperatures.
acceptable limits. pump to fill or control to operate See Hydraulic Fluids and Lubricants
properly. Technical Information Manual,
520L0463.
Malfunctioning valving may not Repair or replace system valving as
Check external system valving. allow system to respond properly. required.
High case pressure causes the
Check pump case pressure. Correct case drain line restrictions.
system to be sluggish.
Check pump inlet pressure/vacuum. High inlet vacuum causes low Correct inlet pressure conditions.
output flow.

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Troubleshooting
(continued)

System Operating Hot Item Description Action

Insufficient volume of hydraulic Fill reservoir to proper level. Verify
Check fluid level in reservoir. fluid will not meet cooling demands proper size of reservoir.
of system.
Insufficient air flow, high input air
Inspect heat exchanger. Check air Clean, repair, or replace heat
temperature, or undersized heat
flow and input air temperature for exchanger as required. Verify
exchanges will not meet cooling
the heat exchanger. proper size of heat exchanger.
demands of the system.
Adjust external system relief valve
setting following manufacturer’s
Check external system relief valve Fluid passing through relief valve recommendations. External relief
setting. adds heat to system. valve setting must be above PC
setting for proper operation.
Check pump inlet pressure/vacuum. High inlet vacuum adds heat to Correct inlet pressure/vacuum
system. conditions.

Low Pump Output Flow Item Description Action

Insufficient hydraulic fluid will limit
Check fluid level in reservoir. output flow and cause internal Fill the reservoir to proper level.
damage to pump.
Allow system to warm up before
operating, or use fluid with the
Fluid viscosity above acceptable appropriate viscosity grade for
Hydraulic fluid viscosity above limits or low fluid temperature will expected operating temperatures.
acceptable limits. not allow the pump to fill or control See Hydraulic Fluids and Lubricants
to operate properly. Technical Information Manual,
520L0463.
Adjust external relief valve
following manufacturer’s
Check external system relief valve Eternal relief valve set below PC recommendation. External relief
setting. setting causes low output flow. valve setting must be above PC
setting to operate properly.
Low PC setting prevents the pump Adjust PC and LS setting. Refer to
Check PC and LS control setting. from achieving full stroke. Adjustment, page 21.
Check pump inlet pressure/vacuum. High inlet vacuum causes low Correct inlet pressure conditions.
output flow.
Check input speed. Low input speeds decrease flow. Adjust input speed.
Incorrect rotational configuration Use pump with appropriate
Check pump rotation. causes low flow. rotational configuration.

Pressure or Flow Instability Item Description Action

Activate PC allowing system to
Air in system causes erratic bleed air. Check inlet line for leaks
Check for air in system. operation. and eliminate source of air
ingression.
Sticking control spools cause erratic Inspect spools for free movement in
Check control spools. operation. bore. Clean or replace.

520L0607 • Rev AI • Sep 2013 19

Service Manual Series 45 J Frame Open Circuit Axial Piston Pumps

Troubleshooting
(continued)

Pressure or Flow Instability Item Description Action

(continued) Low LS setting may cause Adjust LS setting to proper level.
Check LS setting. instability. See Adjustments, page 21.
Blocked LS signal line interferes
Check LS signal line. Remove blockage.
with proper LS operation.
Adjust external relief valve or PC
Insufficient pressure differential control settings to appropriate
Check external relief valve and PC between PC setting and external level. Relief valve setting must be
setting. relief valve. above PC setting to operate
properly.
Chattering external relief valve may
Check external relief valve. cause unstable feedback to pump Adjust or replace relief valve.
control.

System Pressure not Item Description Action

Reaching PC Setting System pressure will not rise above Adjust PC to appropriate setting.
Check PC control setting. PC setting. Refer to Adjustments, page 21.
Adjust external relief valve
External relief valve setting below according to manufacturer’s
Check external relief valve. PC setting presents pressure recommendations. External relief
compensation. valve must be set above PC setting
to operate properly.
Broken, damaged, or missing spring Replace the spring as required.
Inspect PC control spring. will cause erratic operation.
Wear of PC spool causes internal
Inspect PC spool for wear. Replace the spool as required.
leakage in the control.
Inspect PC spool for proper Improper orientation results in poor Correct orientation of spool.
orientation. operation.
Clean PC control components, take
Check PC control for contamination. Contamination may interfere with appropriate action to eliminate
movement of the PC spool. contamination.

High Inlet Vacuum Item Description Action

 Caution Low temperature increases Allow system to warm up before
Check fluid temperature. viscosity. High fluid viscosity causes
High inlet vacuum causes operating.
high inlet vacuum.
cavitation which can damage Blocked or restricted inlet screen
internal pump components. Inspect inlet screen. Clean screen/remove blockage.
causes high inlet vacuum.
Too many fittings, bends, or long Eliminate fittings to make path
Check inlet piping. piping causes high inlet vacuum. more direct.
Select fluid with appropriate
High fluid viscosity causes high inlet viscosity for expected operating
Hydraulic fluid viscosity above temperature. See Hydraulic Fluids
acceptable limits. vacuum. and Lubricants Technical Information
Manual, 520L0463.

20 520L0607 • Rev AI • Sep 2013

Service Manual Series 45 J Frame Open Circuit Axial Piston Pumps

Adjustments

PC Control PC setting is indicated in the pump model code. Refer to the Series 45 J Frame Open Circuit Axial Piston
Pumps Technical Information Manual, 520L0676, for more information.

Warning
Escaping hydraulic fluid under Before performing adjustments, read page 15, Pressure measurement.
pressure can have sufficient
force to penetrate your skin 1. Install a pressure gauge in port M1 to measure system pressure. Install a pressure gauge in case
causing serious injury and/or drain port L1 or L2 to measure case pressure. C
infection. Relieve pressure in
the system before removing 2. Start the prime mover and allow fluid to reach normal operating temperature. Operate a hydraulic
hoses, fittings, gauges, or function to its full extension, loading the pump at maximum pressure and zero flow.
components.
3. Loosen the PC set screw and turn the PC adjusting plug until the desired setting is indicated on the
Unintended movement of the pressure gauge at port M1¹. Clockwise rotation increases pressure, counterclockwise rotation
machine or mechanism may decreases; approximate gain 42 bar [610 psi] per turn.
cause injury to the technician
or bystanders. To protect If the pressure does not increase, an external system relief valve may require adjustment. External
against unintended system relief valve must be set above the PC setting for proper operation.
movement, secure the
machine or disable/disconnect 4. While holding the position of the PC adjusting plug, torque the PC set screw to 7.5 - 10.8 N•m
the mechanism while [5.5 - 8 lbf•ft].
servicing.
5. Stop the prime mover, remove the pressure gauges, and return the system to its normal operating
configuration.

Caution PC control adjustment

Contamination can damage
internal components and void Gauge port M1
the manufacturer’s warranty. PC set screw
Take precautions to ensure 0 - 300 bar [0 - 4351 psi]
system cleanliness when 9/16-28 0 - 300 bar [0 - 4351 psi]
removing and reinstalling 34-68 N•m [25-50 lbf•ft] 9/16-28
system lines. 34-68 N•m [25-50 lbf•ft]

PC adjusting plug
Case drain port L1 0 - 300 bar [0 - 4351 psi]
0 - 300 bar [0 - 4351 psi] 9/16-28
9/16-28 34-68 N•m [25-50 lbf•ft]
34-68 N•m [25-50 lbf•ft]
P104 365E

Pressure change
Control option PC adjustment LS adjustment
LS, LD, LB, LE, PC, RP 42 bar/rev [609 PSI/rev]
J Frame
BB, BC, BP, BS 36 bar/rev [534 PSI/rev] 17.2 bar/rev [250 PSI/rev]
AB, AC, AD, AJ, AS 8.5 bar/rev [123 PSI/rev]

1
P C setting is referenced to case pressure. Subtract case pressure from system pressure to compute the actual setting.

520L0607 • Rev AI • Sep 2013 21

Service Manual Series 45 J Frame Open Circuit Axial Piston Pumps

Adjustment (continued)

LS Control The LS setting is indicated in the pump model code. Refer to the Series 45 J Frame Open Circuit Axial
Piston Pumps Technical Information Manual, 520L0676, for more information.

Warning
Escaping hydraulic fluid Before performing adjustments, read page 15, Pressure measurement.
under pressure can have
sufficient force to penetrate 1. Install a pressure gauge in port M1 to measure system pressure. Install a pressure gauge in drain
your skin causing serious port L1 or L2 to measure case pressure. Tee-in a gauge to the LS/remote PC signal line (port X).
injury and/or infection. C
Relieve pressure in the system
before removing hoses, 2. Start the prime mover and allow fluid to reach normal operating temperature. Slowly operate a hydraulic
fittings, gauges, or function that will demand approximately half flow from the pump, but keep system pressure below the
components. PC set point.

Unintended movement of the 3. Loosen the LS set screw. While watching the pressure gauges, turn the LS adjusting plug until the
machine or mechanism may desired pressure differential between port M1 and port X is achieved1. Clockwise rotation increases
cause injury to the technician the setting, counterclockwise rotation will decrease it; approximate gain = 17 bar [250 psi] per turn.
or bystanders. To protect
against unintended 4. While holding the position of the LS adjusting plug, torque the LS set screw to 7.5 - 10.8 N•m [5.5-8
movement, secure the lbf•ft].
machine or disable/
disconnect the mechanism 5. Operate a hydraulic function to its full extension loading the pump at maximum pressure and zero
while servicing. flow.

6. Loosen the PC set screw and turn the PC adjusting plug until the desired setting is indicated on the
pressure gauge at port M12. Clockwise rotation increases pressure, counterclockwise rotation
If the pressure does not decreases it; approximate gain = 42 bar [610 psi] per turn.
increase, an external system
relief valve may require 7. While holding the position of the PC adjusting plug, torque the PC set screw to 7.5 - 10.8 N•m [5.5-8
adjustment. External system lbf•ft].
relief valve must be set above
the PC setting for proper 8. Stop the prime mover, remove the pressure gauges, and return the system to its normal operating
operation. configuration.

LS control adjustment

Caution Gauge port M1 LS/ remote PC signal port X

Contamination can damage
internal components and void 0 - 300 bar [0 - 4351 psi] LS set screw
the manufacturer’s warranty. 9/16-28 0 - 300 bar [0 - 4351 psi]
Take precautions to ensure 34-68 N•m [25-50 lbf•ft] 9/16-28
system cleanliness when
removing and reinstalling 7.5-10.8 N•m [5.5-8 lbf•ft]
system lines.
Case drain port L1 LS adjusting plug

0 - 300 bar [0 - 4351 psi] 0 - 300 bar [0 - 4351 psi]

9/16-28 9/16-28
34-68 N•m [25-50 lbf•ft] 34-68 N•m [25-50 lbf•ft]

P104 367E

1
The LS setting is a differential pressure. Subtract pilot pressure at port X from system pressure at port M1 to compute the
actual setting.
2
PC setting is referenced to case pressure. Subtract case pressure from system pressure to compute the actual setting.

22 520L0607 • Rev AI • Sep 2013

Service Manual Series 45 J Frame Open Circuit Axial Piston Pumps

Minor Repair

Shaft Seal Replacement The Series 45 open circuit variable pumps use a lip-type shaft seal. You can replace this seal without
major disassembly of the unit. Replacing the shaft seal requires removing the pump from the
machine.

Removal
1. Using the appropriate snap-ring pliers, Shaft seal and retaining ring
remove the retaining ring (K010) from the
housing. K010

2. Remove the shaft seal (K020) from the bore in K020

C Caution the pump housing and discard. C
Don’t damage the pump
housing or shaft. Remove second seal if pump is so equipped. See
illustration below.

3. Puncture the face of the seal with a packing

hook, or use a slide-hammer type puller to
remove the seal.

E101 187

Installation
4. Inspect the pump housing and new seal for damage. Inspect the sealing area on the shaft for rust,
wear, or contamination. Polish the sealing area on the shaft if necessary.

5. Lubricate the lip of the new shaft seal with clean hydraulic fluid. Place a protective sleeve over the
shaft end to prevent damage to the seal during installation.
 Caution 6. Keeping the seal perpendicular to the shaft, press the new seal into the housing just far enough to
Premature bearing failure can clear the retaining ring groove.  Install seal with the cupped side toward the shaft bearing. Do
result if the shaft seal contacts not damage the seal during installation.
the shaft bearing.
Press the seal into the housing Install second seal if pump is so equipped. See illustration below.
only far enough to clear the
retaining ring groove.
7. Using the appropriate snap ring pliers, install the seal retaining ring.

8. Remove the installation sleeve.

Double seal and retaining ring

K010

K020

K020

E108 672E

520L0607 • Rev AI • Sep 2013 23

Service Manual Series 45 J Frame Open Circuit Axial Piston Pumps

Minor Repair

Auxiliary pads You may install auxiliary mounting pads on pumps equipped with through-drive radial ported
endcaps. Follow these steps to either remove, replace, or exchange auxiliary mounting pads.

Removal
1. Remove the screws (J130), retaining the cover plate (J110) or auxiliary pump (not shown). Remove
the shipping cover or auxiliary pump and its seal (J120).

2. Remove the drive coupling (J140) if present.

3. Remove the 4 screws (J100) retaining the pad adapter (J080) to the endcap. Discard the pad
adapter O-ring (J090) if present. Also discard the J095 O-ring.

Auxiliary mounting pads

J095
J090
J080

J140
J120
J110
J100 J095
8 mm
48.5 - 61 N•m J090
[35 - 45 lbf•ft] J080

J095
J130 J140
3/4 inch J090

91 - 111 N•m J120 J080 J095

[67 - 82 lbf•ft]
J110 J100 J085
J140
8 mm
48.5 - 61 N•m
J130 J120
[35 - 45 lbf•ft]
9/16 inch
J110
38 - 50 N•m
[27 - 37 lbf•ft] E101 256

Installation
4. Lubricate new O-ring (J090) with petroleum jelly. Install the pad adapter to the endcap.

5. Install the 4 screws (J100 ) and torque to 48.5 - 61 N•m [35 - 45 lbf•ft].
Caution 6. Install the drive coupling (J140) if present.
Shipping cover is intended
only to retain coupling during 7. Install shipping cover or auxiliary pump with seal (J120). 
shipment and storage. Do not
operate pump with coupling 8. Install the screws (J130) and torque to 94 - 115 N•m [67 - 82 lbf•ft]. If you have an auxiliary A pad,
and shipping cover installed. install the screws (J130) and torque to 37 - 50 N•m [27 - 37 lbf•ft].

24 520L0607 • Rev AI • Sep 2013

Service Manual Series 45 J Frame Open Circuit Axial Piston Pumps

Minor Repair (continued)

LS and PC Controls Disassembly Control assembly

C103
1. Remove the 4 screws (C300) holding the 3/16 inch
control housing onto the end cap.
10.8 - 13.5 N•m
2. Remove the control and discard the 4 C104 [8 - 10 lbf•ft]
3/16 inch
interface O-rings (C200).
C103A
10.8 - 13.5 N•m
3. Remove the PC set screw (C102), PC adjusting [8 - 10 lbf•ft] C132
plug (C138), O-ring (C138A), springs (C134,
C135), and seat (C133). Discard the O-ring. C104A
C105
4. Remove the plug (C103), O-ring (C103A), and C112 3/16 inch
PC spool (C132) from the control housing.
10.8 - 13.5 N•m
Discard the O-ring. Note orientation of the
[8 - 10 lbf•ft]
spool for reassembly. C105A

C102
C106A
For PC only controls, skip steps 5 through 7 6 mm
C106 7.5 - 10.8 N•m
3/16 inch [5.5 - 8 lbf•ft]
5. Remove the plug (C105) and O-ring (C105A), 10.8 - 13.5 N•m
or the plug (C106) and O-ring (C106A). Discard C200
[8 - 10 lbf•ft]
the O-ring (C105A or C106A). C133 C300
C113
6. Remove the LS set screw (C102), LS adjusting C135 4 mm
C115
plug (C118), O-ring (C118A), back‑up rings 5.4 - 7.5 N•m
(C118B), springs (C114, C115), and seat (C113). C114 C134 [4 - 5.5 lbf•ft]
Discard the C118A O-ring. C118B
C138A
7. Remove the C104 plug, C104A O-ring, and C118A
C112 LS spool from the control housing; C138
C118B
discard the O-ring. Note orientation of the
spool for reassembly. C118
E101 226

LS control shown; parts C104 through C106 and

C112 through C118 are not used on PC control

Inspection
8. Inspect the adjusting plugs for wear at the tips and where they contact the springs; replace as
necessary.

9. Inspect the springs and spring guides for wear or damage; replace as necessary.

10. Carefully inspect the spools. Ensure the sealing lands are free of nicks and scratches. Check the
ends that contact the spring guides for wear. Replace spools as necessary.

11. Inspect the control housing for damage. Check the spool bores for excessive wear.

12. Clean all parts and lubricate spools, springs, guides and new O-rings with clean hydraulic fluid.

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Service Manual Series 45 J Frame Open Circuit Axial Piston Pumps

Minor Repair (continued)

LS and PC Controls
(continued) Reassembly Control assembly
13. Install the PC spool (C132), spherical end first,
into the PC bore. Using a new O-ring (C103A), C103
install the plug (C103). Torque the plug (C103) 3/16 inch

to 10.8 - 13.5 N•m [8 - 10 lbf•ft]. 10.8 - 13.5 N•m

C104 [8 - 10 lbf•ft]
14. Place the two PC springs (C134, C135) onto the 3/16 inch

spring guide (C133) and install into the PC C103A

10.8 - 13.5 N•m
bore. Place a new O-ring (C138A) onto the PC [8 - 10 lbf•ft] C132
adjusting screw and thread it into the PC bore
until flush, then make another full turn. Install
C104A
and torque the PC set screw (C102) to C105
7.5 - 10.8 N•m [5.5-8 lbf•ft]. C112 3/16 inch

For PC only controls, skip steps 15 through 17. 10.8 - 13.5 N•m

[8 - 10 lbf•ft]
C105A

15. Install the LS spool (C112), spherical end first, C102

C106A
into the LS bore. Using a new O-ring (C105A 6 mm
or C106A), install the plug (C105 or C106). C106 7.5 - 10.8 N•m
Torque the plug (C105 or C106) to 3/16 inch [5.5 - 8 lbf•ft]
10.8 - 13.5 N•m [8 - 10 lbf•ft].
10.8 - 13.5 N•m C200
16. Using a new O-ring (C104A), install the plug [8 - 10 lbf•ft]
(C104). Torque the plug to 10.8 - 13.5 N•m C133 C300
C113
[8 - 10 lbf•ft]. C135 4 mm
C115
5.4 - 7.5 N•m
17. Place the two LS springs (C114, C115) onto the C114 [4 - 5.5 lbf•ft]
spring guide (C113) and install into the LS C134
bore. Place a new O-ring (C118A) and back-up C118B
C138A
rings (C118B) onto the LS adjusting screw and C118A
thread it into the LS bore until flush, then C118B
C138
make another full turn. Install and torque the
LS set screw (C102) to 7.5 - 10.8 N•m C118
E101 226
[5.5-8 lbf•ft]
LS control shown; parts C104 through C106 and
18. Using petroleum jelly to retain them, install
C112 through C118 are not used on PC control
the 4 interface O-rings (C200) in the recesses
on the control housing.

19. Install the control assembly onto the endcap using the 4 screws (C300). Torque the screws to 5.4
- 7.5 N•m [4 - 5.5 lbf•ft]. Torque screws in a criss-cross pattern and re-torque the first screw to
ensure proper torque retention.

20. Check and adjust the control setting. See Adjustments, page 21

26 520L0607 • Rev AI • Sep 2013

Service Manual Series 45 J Frame Open Circuit Axial Piston Pumps

Minor Repair (continued)

Electric Controls Disassembly Control assembly

1. Remove four screws (C300).
C103

2. Remove the control and discard the four C125 C104

O-rings (C200). C132
C300 C112

3. Remove set screws (C102), PC adjusting C155

plug (C138) with O-ring (C138A), springs
C102
(C134, C135), and seat (C133). Discard the
O-ring if it is damaged.
C150
4. Remove plug (C103). Remove PC spool
C149
(C132). Note orientation of the spool for C154
reassembly. C152 G030
G020
5. Remove plug (G030), and orifice (G020). C151 C200

C133
6. Remove LS adjusting plug (C118), springs C113
(C114, C115), and seat (C113). C135
C115
7. Remove plug (C104), and spool (C112). Note C153
the orientation of the spool for reassembly C114 C134

8. Remove four screws (C151). Remove the C138A

manifold (C152) and discard the two C118
P108 668E
interface O-rings (C154). C138

9. For electric proportional controls only:

Remove the electric control manifold drain orifice (C149).

10. Remove plug (C153). Remove the cartridge valve nut (C125), electric solenoid (C155), and cartridge
valve (C150) from the electric control manifold.

Inspection
1. Inspect the adjusting plugs for wear at the tips and where they contact the springs; replace as
necessary.

2. Inspect the springs and spring guides for wear or damage; replace as necessary.

3. Carefully inspect the spools. Ensure the sealing lands are free of nicks and scratches. Check the
ends that contact the spring guides for wear. Replace spools as necessary.

4. Inspect the control housing for damage. Check the spool bores for excessive wear.

5. Remove debris from orifices if necessary. Ensure the servo control orifice backup plug is clean, and
remove debris if necessary.

6. Clean all parts and lubricate spools, springs, guides and new O-rings with clean hydraulic fluid.

520L0607 • Rev AI • Sep 2013 27

Service Manual Series 45 J Frame Open Circuit Axial Piston Pumps

Minor Repair (continued)

Electric Controls Reassembly

(continued) 1. Install the servo control orifice (G020), and torque to 2-3.4 N•m [18-30 in•lb]. Then install the orifice
backup plug (G030), and torque to 2-3.4 N•m [18-30 in•lb].

2. Install the PC spool (C132), spherical end first, into the PC bore. Install plug (C103). Torque the plug
to 10.8 - 13.5 N•m [8 - 10 lbf•ft].

3. Place the two PC springs (C134, C135) onto the spring guide (C133) and install into the PC bore.
Place a new O-ring (C138A) onto the PC adjusting screw (C138) and thread it into the PC bore until
flush, then make another full turn. Install and torque the PC set screw (C102) to 7.5 - 10.8 N•m
[5.5-8 lbf•ft].

4. Install the LS spool (C112), spherical end first, into the LS bore.

5. Install plug (C104). Torque the plug to 10.8 - 13.5 N•m [8 - 10 lbf•ft].

6. Place the two LS springs (C114, C115) onto the spring guide (C113) and install into the LS bore.
Thread adjusting screw (C118) into the LS bore until flush, then make another full turn. Install and
torque the LS set screw (C102) to 7.5 - 10.8 N•m [5.5-8 lbf•ft].

7. Install the electric control manifold drain orifice (C149) and torque to 2-3.4 N•m [18-30 in•lb].

8. Install the cartridge valve (C150) into the electric control manifold (C152). Torque to 25.8-28.5
N•m [19-21 lbf•ft]. DO NOT OVERTORQUE the cartridge valve.

9. Install the electric solenoid (C155), and solenoid coil nut (C125). Torque to 6.8-9.5 N•m [5-7 lbf•ft]

10. Install plug (C153). Torque the plug to 10.8 - 13.5 N•m [8 - 10 lbf•ft].

11. Using petroleum jelly to retain them, install the two interface O-rings (C154) in the recesses on the
electric control manifold.

12. Install the manifold assembly onto the control housing using four screws (C151). Torque the screws
to 5.4 - 7.5 N•m [4 - 5.5 lbf•ft]. Torque the screws in a criss-cross pattern and re-torque the first
screw to ensure proper torque retention.

13. Using petroleum jelly to retain them, install the four interface O-rings (C200) in the recesses on the
control housing.

14. Install the control assembly onto the endcap using the four screws (C300). Torque the screws to
5.4 - 7.5 N•m [4 - 5.5 lbf•ft]. Torque screws in a criss-cross pattern and re-torque the first screw to
ensure proper torque retention.

15. Check and adjust the control setting. See Adjustments, page 21-22.

28 520L0607 • Rev AI • Sep 2013

Service Manual Series 45 J Frame Open Circuit Axial Piston Pumps

Minor Repair (continued)

Servo Control Orifice Disassembly Control assembly

1. Remove four screws (C300).

2. Remove the control and discard the four

O-rings (C200). X

3. Remove PC plug (C103), and PC spool (C132)

from the control housing.
B

M2
Note the orientation of the spool for reassembly.

4. Remove backup plug (G030), and orifice L2

(G020). S L1 P108 669E

Reassembly
1. Install the orifice (G020), and torque to 2-3.4
N•m [18-30 in•lb]. Then install the orifice
backup plug (G030), and torque to 2-3.4 N•m
[18-30 in•lb].

2. Install the PC spool (C132), spherical end first,

into the PC bore. Install plug (C103). Torque
the plug to 10.8 - 13.5 N•m [8 - 10 lbf•ft].

3. Using petroleum jelly to retain them, install

the four O-rings (C200) in the recesses on the
control housing.

4. Install the control assembly onto the endcap

using four screws (C300). Torque the screws to
5.4 - 7.5 N•m [4 - 5.5 lbf•ft]. Torque screws in a
criss-cross pattern and re-torque the first
screw to ensure proper torque retention.

520L0607 • Rev AI • Sep 2013 29

Service Manual Series 45 J Frame Open Circuit Axial Piston Pumps

Minor Repair (continued)

Plug and fitting sizes and If any plugs or fittings are removed from the unit during service, install and torque as indicated
torques here. This drawing is a composite. Your configuration may differ but here is the appropriate
wrench size and torque:

Plug locations, sizes, and torques

K040
J041 3/8 inch
1/4 inch
55 - 135 N•m
27 - 47 N•m [40 - 100 lbf•ft]
[20 - 35 lbf•ft]

K040A
J041A

K070A
K070
3/8 inch

55 - 135 N•m
[40 - 100 lbf•ft]
E101 257

30 520L0607 • Rev AI • Sep 2013

Service Manual Series 45 J Frame Open Circuit Axial Piston Pumps

Notes

520L0607 • Rev AI • Sep 2013 31

Products we offer: Danfoss Power Solutions is a global manufacturer and supplier of high-quality hydraulic and
electronic components. We specialize in providing state-of-the-art technology and solutions that
 Bent Axis Motors excel in the harsh operating conditions of the mobile off-highway market. Building on our extensive
 Closed Circuit Axial Piston applications expertise, we work closely with our customers to ensure exceptional performance for a
Pumps and Motors broad range of off-highway vehicles.

 Displays We help OEMs around the world speed up system development, reduce costs and bring vehicles to
 Electrohydraulic Power market faster.
Steering Danfoss – Your Strongest Partner in Mobile Hydraulics.
 Electrohydraulics Go to www.powersolutions.danfoss.com for further product information.
 Hydraulic Power Steering
Wherever off-highway vehicles are at work, so is Danfoss.
 Integrated Systems
 Joysticks and Control We offer expert worldwide support for our customers, ensuring the best possible solutions for
Handles outstanding performance. And with an extensive network of Global Service Partners, we also provide
 Microcontrollers and comprehensive global service for all of our components.
Software
Please contact the Danfoss Power Solution representative nearest you.
 Open Circuit Axial Piston
Pumps
 Orbital Motors
 PLUS+1® GUIDE
 Proportional Valves
 Sensors
 Steering
 Transit Mixer Drives

Comatrol
www.comatrol.com
Schwarzmüller-Inverter
www.schwarzmueller- Local address:
inverter.com
Turolla
www.turollaocg.com
Valmova
www.valmova.com
Hydro-Gear
www.hydro-gear.com
Daikin-Sauer-Danfoss
www.daikin-sauer-danfoss.com

Danfoss Danfoss Danfoss Danfoss

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