TM 5-3895-383-24
Problem
The propel system engages very suddenly when the
operator is making a shift.
Probable Cause
The orifices are missing from the piston pumps.
The shuttle valve spool that is inside the flushing valve
is sticking.
The servo valve spool is sticking.
Problem
The propel system operates in one direction only.
Probable Cause
The pump servo valve has failed.
The pump servo piston has failed.
The rocker arm section of the pump swashplate
assembly has failed.
One of the multifunction valves is damaged.
The shuttle valve spool is sticking.
The control valve has failed.
Problem
The propel system does not disengage when the propel
control lever is returned to neutral.
Probable Cause
The pump servo valve has failed.
The pump s ervo piston has failed.
The rocker arm section of the pump swashplate
assembly has failed.
The neutral adjustment of the servo valve is incorrect.
The linkage rod between the directional control valves is
incorrectly adjusted.
Problem
The parking brake does not release when the parking
brake button is pulled up.
Probable Cause
The parking brake button has failed.
There is a malfunctioning piston seal in the brake group.
The parking brake valve has failed.
There is a fault in the electric circuit.
The neutral start switch has failed.
The neutral start relay has failed.
Low charge pressure.
The brake relay has failed.
The relief valve on the gear pump is damaged or
incorrectly adjusted.
Failure of the gear pump.
Problem
The parking brake does not engage when the parking
brake button is pushed down.
Probable Cause
The parking brake button has failed.
The brake relay has failed.
The brake discs are worn.
There is a pinched brake line.
The parking brake valve has failed.
There is a fault in the electrical circuit.
Problem
There are external oil leaks from either of the piston
motors.
Probable Cause
Motor case pressure is too high.
There is a restriction in the oil return line to the hydraulic
oil tank.
There are damaged seals due to pressure peaks, use of
unapproved hydraulic oil, or an incorrect tightening
torque.
Problem
The oil in the propel system overheats.
Probable Cause
An incorrect type of oil is used in the hydraulic circuit.
The oil cooler is internally restricted.
The radiator and/or the oil cooler is externally restricted.
There is a low charge line pressure that is caused by
excessive internal leakage in the circuit.
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