18/09/2023 12:43 SIS 2.
Measuring Fuel Leakage Past the Fuel Injectors{0782, 1251, 1254, 1290, 1713}
2010/02/04
(REHS3428-07)
SMCS - 0782, 1251, 1254, 1290, 1713 i03855790
Excavator:
PSP
202 -0009
315D (S/N: JKH1-UP)
320D (S/N: GDC1-UP)
Introduction 12: 3/09/1 6955
4
RE 3:32+ 8
Do not perform any procedure in this Special Instruction until you have read the information and
you understand the information.
H
© 2 S342 00:00
There have been isolated occurrences of excessive fuel leakage past the electronic unit injectors
on some engines.
023 8
Cat
Accelerated wear on the delivery valve results in an increased leak rate. The high pressure
erp
pump cannot generate enough fuel flow or volume to compensate for the leakoff rates above the
illa
critical value 38 mL (1.3 oz) per 30 seconds of cranking for six cylinder engines at a speed of
rI
150 rpm. The high pressure pump cannot generate enough fuel flow or volume to compensate
for the leakoff rates above the critical value 25 mL (0.85 oz) per 30 seconds of cranking for four
nc.
cylinder engines at a speed of 150 rpm.
If the engine turns over but the engine does not start, refer to Troubleshooting, "Engine Cranks
but Will Not Start".
Test Procedure
NOTICE
Before begining any work on the fuel system, refer to Operation
and Maintenance Manual, "General Hazard Information and High
Pressure Fuel Lines" for safety information.
Refer to Systems Operation, Testing and Adjusting,
"Cleanliness of Fuel System Components" for detailed
information on the standards of cleanliness that must be
observed during ALL work on the fuel system.
Table 1
Required Tools
Tool Part Number Part Description Qty
A 334-3221 Fuel Leakoff Kit 1
https://sis2.cat.com/?_ts=1695037951270#/print-preview/service/%257B%2522formattedPublicationDate%2522%253A%25222010%252F02%25… 1/4
18/09/2023 12:43 SIS 2.0
1. Ensure that the engine is shut down.
Illustration 1 g02103090
Injector harness
2. Disconnect the injector harness (1) from the front of the engine.
https://sis2.cat.com/?_ts=1695037951270#/print-preview/service/%257B%2522formattedPublicationDate%2522%253A%25222010%252F02%25… 2/4
18/09/2023 12:43 SIS 2.0
Illustration 2 g02103093
Typical example
Note: Direct any leaking fuel into a suitable container.
3. Remove the bolt (2) from the "fuel relief block" and save the bolt for reinstallation.
Illustration 3 g02103095
Fuel leakoff kit
(A) Tooling
(3) Clear plastic hose
4. Install tooling (A) to the "fuel relief block".
a. Slide the tooling through the banjo bolt in order to replace the bolt that was removed in
the previous step.
b. Thread the tooling into the "fuel relief block" and slightly tighten the tooling.
5. Connect a plastic hose (3) onto the tooling. Place the opposite end of the plastic hose into a
suitable container that is clean.
6. Crank the engine with the starting motor for 30 seconds.
7. Record the amount of fuel that has been collected. Conduct the test three times. Calculate
the average of the three values.
8. For six cylinder engines, if more than 38 mL (1.3 oz) of fuel has been collected during the 30
second crank test, then there is high leakoff of the electronic unit injectors. For four cylinder
engines, if more than 25 mL (0.85 oz) of fuel has been collected during the 30 second crank
https://sis2.cat.com/?_ts=1695037951270#/print-preview/service/%257B%2522formattedPublicationDate%2522%253A%25222010%252F02%25… 3/4
18/09/2023 12:43 SIS 2.0
test, then there is high leakoff of the electronic unit injectors. If this is the case, replace the
electronic unit injectors and the fuel injection lines. Return the original electronic unit
injectors and the fuel injection lines to the parts return center.
9. For six cylinder engines, if less than 38 mL (1.3 oz) of fuel has been collected for the 30
second crank test, then there is not high leakoff of the electronic unit injectors. For four
cylinder engines, if less than 25 mL (0.85 oz) of fuel has been collected for the 30 second
crank test, there is not high leakoff of the electronic unit injectors. Refer to Troubleshooting,
"Engine Cranks but Will Not Start" in order to diagnose the problem.
10. Remove the tooling. Reinstall the bolt (2) and two new washers to the "fuel relief block".
11. Reconnect the injector harness (1) at the front of the engine.
12. Send the leakoff measurements to the Technical Communicator at your Caterpillar dealer.
PSP-00096955
2023/09/18
11:55:44+00:00
i03203547
© 2023 Caterpillar Inc.
https://sis2.cat.com/?_ts=1695037951270#/print-preview/service/%257B%2522formattedPublicationDate%2522%253A%25222010%252F02%25… 4/4
