TROUBLESHOOTING
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.
CAUTION
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 A 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.
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