TM 5-3895-359-14&P
4.
Inspect Charge Check Valves
The Charge Check Valves are located in the pump end
cap, under the Charge Pump. Following the procedures
in the Minor Repair Section of this manual, remove the
Charge Pump. Remove both Charge Check Valves and
keep in same relation to the end cap.
NOTE:
Protect exposed cavities into pump
from foreign material.
Inspect the check valve for spring loading by pushing
against the internal ball. A slight resistance should be
felt as the ball is pushed off its seat. The internal spring
should return the ball to its seat when force is removed.
Check for any foreign material inside valve.
When the problem occurs in one direction only,
interchange the check valves and see if the problem
changes to the other direction. If so, one check valve is
malfunctioning and should be replaced.
5.
Inspect Pump Charge Relief Valve
If Charge Pressure is low (below 190 ∆PSI) in neutral
only (okay in forward and reverse), the Charge Relief
Valve located in the Charge Pump should be inspected.
Remove the hex plug and relief valve parts. Inspect for
foreign material holding poppet open, and for galling or
wear on poppet and seat in the charge pump.
Adjustment of Charge Pressure in Neutral is
accomplished by changing the shims behind the spring.
6.
Inspect Motor Charge Relief Valve
If Charge Pressure is low (below 160 a ∆PSI) in forward
and reverse (okay in neutral), the Charge Relief Valve
located in the motor manifold should be inspected.
Remove the hex plug and relief valve parts. Inspect for
foreign material holding poppet open, and for galling or
wear on poppet and seat in the manifold.
Adjustment of Charge Pressure in forward and reverse
is accomplished by changing the shims behind the
spring.
CAUTION
Make certain the pressure setting of
the motor charge relief valve is below
the pressure setting of the pump
charge relief valve. Otherwise the
cooling circuit will not function
properly.
6-14
