TRUCK SERVICE MANUAL
FUEL SYSTEM
(a) Leakage past the piston sealing rings. (This is
Replace sealing rings as required. (See Fig. 6-1-122 for
accompanied with loss of fluid from the reservoir
assembly instructions.)
and appearance of oil out the cylinder vent when
the piston is actuated to top travel.)
Repair or replace as required.
(b) Hydraulic lock-up valve leaking. (This may be
Correction
checked by placing valve in closed position and
applying air pressure. Indicated travel of piston
Check the load cell on a valve spring tester at 380 lbs
rod verifies leaking hydraulic lock-up valve.)
[172 kg] load. The load cell should read 380 lbs [172 kg]
.
Check 10 - Load Test Cell
Correct the gauge with the recalibration screw on the
gauge face.
Cause
Correction
Gauge on load cell has become miscalibrated as a result
of mis-handling such as dropping or excessive loading.
Use correct link for injector being calibrated.
Check 11 - Plunger Actuating Link
Align link guide bracket so that it does not contact link at
any point. Inspect link visually and during running of
Cause
stand and
replace if necessary.
Use of wrong injector model link causing hydraulic piston
return spring to be worked at a height other than that
Correction
when checking the load cell. Plunger actuating link
binding on link guide bracket.
Replace O-ring with new one. If an O-ring of a larger
crosscut diameter is used, the injector may bounce on
Plunger actuating link distorted or cracked on socket and
the cup seat and thus affect transfer groove and
causing cocking during operation of stand.
metering orifice timing. Any bouncing of the injector on
the cup seat must be corrected.
Check 12 - Test Oil Leaks
Correct as necessary, remove rear panel.
Cause
Correction
Cup seat O-ring leaking. (Leak may appear as mist.)
Keep tank 3/4 full of Cummins 99011-68 test oil or Shell
Cup seat block-to-solenoid line (line H in Fig. 6-.1-121)
Injector Oil No. 66631. Use of oil not meeting these
leaking in between tank and front panel. (To check this,
specifications or diluted until viscosity or specific gravity
route line H temporarily in front of panel and operate test
stand.)
Visual leaks.
Check 13 - Test Oil Condition
Cause
Improper fuel or dilution.
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