SPRING 8F1348 - Caterpillar

Test Procedure:
Before the machine is tested it is necessary to ensure that the linkage dimensions and pedal height are correct. (Reference 1074802 Control Group - Brake). Effective with serial numbers 7ZM221 and 8ZM191 the 1074802 (Change 07) Inching Valve location changed. Linkage dimensions are:
It is also important to check that the brakes have been bled, the inching valve correctly adjusted and that there is a small amount of free play on the master cylinder input rod. Procedures already exist for brake bleeding and inching adjustment. Making sure that the master cylinder is not actuated by lack of free play on the input rod can be carried out by checking that the pin moves freely inside the cylinder yoke. The machine should be warmed up to operating temperature before starting the test. Oil temperature in the hydraulic tank should be 50 5 degree C. Warming up can be by cycling the implement functions and occasionally blowing the rack back, dump, and raise relief valves.
Do not hold relief for more than 20 seconds.
9. Reconnect the inching rod and check signal pressure (PS) with the valve closed at high idle. (Neutral high idle PS = 3100 300 Kpa).10. Ensure that the master cylinder is not actuated, by checking that the pin turns freely in the linkage yoke connected to the master cylinder input rod.11. Check that the inching valve shaft is pre-rotated as far as possible without causing the PS pressure to decrease. (See Inching Improvement Adjustment Procedure).12. Recheck PS at high idle in neutral.13. Perform hystat brake and inching test to determine that the linkage that controls the hystat brake and service brake are set correctly. This test can be carried out with the machine on its wheels, but extreme caution must be taken when generating drive pressure against the parking brake. Wheel chocks should be used.a. Disable the park brake neutralization feature.The hydraulic system neutralizer can be disabled by following this procedure:- Remove fuse panel cover.- Remove audible alarm relay and parking brake relay.- Insert a 2G5298 Wire Assembly or equivalent jumper wire into locations F3 and D5 of the six-way micro relay block. This will supply direct power to the transmission direction control switch and will ignore the position of the parking brake lever.
When testing is complete, be sure to remove the jumper wire and replace the relays.
b. Machine test conditions: Engine speed low idle to mid speed (1600 RPM) transmission in forward. Park brake on, service brake off to on, steering in neutral, implements in neutral and speed select switch in "slow" mode.c. Increase engine speed until drive pressure (AB) is 15000 5000 Kpa. Slowly apply the service brake until AB drops to 6000 200 Kpa. Check:Signal Pressure (PS) = 650 250 KpaBrake Pressure (SB = 200 Kpa d. Continue to slowly apply the service brake until the service brake pressure (SB) is 500 200 Kpa.Check:Signal Pressure (PS) = 350 250 KpaDrive pressure (AB) = 3100 1500 Kpae. Check that