TM 5-3895-383-24
The operating pressures are exceeding the relief
pressures due to mechanical problems.
The thermal bypass valve has a malfunction.
Problem
Low charge pressure (Neutral).
Probable Cause
The hydraulic oil level is low.
The charge filter in the propel system is in the bypass
mode.
The high idle of the machine is too low.
There is an inadequate flow of oil from gear pump.
There is excessive leakage from the motor case.
There is excessive leakage from the pump case.
The seal on the parking brake is leaking.
Problem
Low charge pressure (Propelling).
Probable Cause
There is excessive leakage from the motor case.
There is excessive leakage from the pump case.
Electrical Circuit For The Propel Brake
Interlock
When the parking brake switch is placed in the ON position,
the axle and the drum valves (brake interlock) are de-
energized. This will prevent the pumps from stroking. Oil flow
to the parking brake is stopped and the parking brake is
applied. The brake interlock valves will not de-energize when
the propel lever is out of the neutral position.
Problem
You are unable to propel the machine.
Probable Cause
The brake fuse is open.
The neutral start switch is improperly adjusted or the
neutral star switch has failed in the open position.
Relay "P9" has failed.
An open circuit exists in the brake interlock valves
and/or the harness for the neutral start switch.
The parking brake switch has failed.
An open circuit exists in the harness for the interlock
system.
Problem
The parking brake does not engage.
Probable Cause
Relay "P6" has failed.
The parking brake switch has failed.
A short circuit exists in the harness for the interlock
system.
Problem
The machine moves when the parking brake switch is
moved to the OFF position and the propel control lever is
out of NEUTRAL position.
Probable Cause
The neutral start switch is failed in the closed position.
Relay "P7" has filed.
An open circuit exists in the harness for relay "P7".
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