
T415 Operation & Service Manual
800.392.2686
87
Maintenance
52
EATON
Heavy-Duty Series 2 Hydrostatic Pumps Parts and Repair E-PUPI-TS004-E October 2004
1. Inspect External Pump Control Linkage for:
Manual Operated Controls
A. Mis-adjusted or disconnected
B. Binding, bend or broken
Hydraulic Remote Controls
A. Improper pilot pressure
B. Defective proportional valve (see proportional
valve manual)
Electrical Operated Controls
A. Disconnected electric signal connection
2. Inspect Pump Control Valve for:
Manual Operated Controls
A. Plugged control orifice
B. Damaged mounting gasket
C. Mis-adjusted, damaged or broken neutral
return spring
D. Broken control connector pin
E. Broken or missing control linkage pin(s)
F. Worn, struck or bent control spool
Hydraulic Remote Controls
A. Plugged control orifice
B. Damaged mounting gasket
C. Mis-adjusted, damaged or broken neutral
return spring
D. Broken control connector pin
E. Broken or missing control linkage pin(s)
F. Worn, struck or bent control spool
G. Worn, or stuck hydraulic control pistons
Electrical Operated Controls
A. Plugged control orifice
B. Damaged mounting gasket
C. Worn, stuck or bent control spool
D. Stuck solenoid valve(s)
E. Defective solenoid coil(s)
F. Mis-adjusted Potentiometer
G. Defective Potentiometer
H. Mis-adjusted speed sensor (on motor when
used)
I.
Defective speed sensor
J. Defective electronics module
3. Inspect Servo Piston for:
A. Improper servo piston adjustment
4. Inspect System Relief Valves for:
A. Improper pressure relief setting (consult own-
ers/operator manual for system relief valve set-
tings)
B. Valve poppet held off seat
C. Broken valve springs (2)
D. Broken valve stem
5. Inspect Shuttle Valve for:
A. Bent or broken return centering spring
B. Worn or stuck shuttle spool
C. Bent or broken shuttle spool
6. Inspect Charge Check Valves for:
A. Valve held off seat
B. Broken valve spring
7. Check Oil Level in Reservoir:
A. Consult owner/operators manual for the proper
type fluid and level
8. Inspect Heat Exchanger for:
A. Obstructed air flow (air cooled)
B. Obstructed water flow (water cooled)
C. Improper plumbing (inlet to outlet)
D. Obstructed or insufficient fluid flow
E. Cooling fan failure (if used)
9. Inspect Heat Exchanger By-Pass Valve for:
A. Improper pressure setting
B. Stuck or broken valve
Troubleshooting
Tips