TSE DPT60, Owner'S Manual

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28
Series 90 Toubleshooting
Transmission Operates Normally in One Direction Only
Check Description Action
1. Input to pump control.
2. Pump displacement control.
3. Interchange system pressure limit-
ers, high pressure relief valves, and
system check valves.
4. Charge pressure.
Input to control module is operating
improperly.
Control linkages are not secure, control
orifices are blocked, etc.
Interchanging the multi-function valves
will show if the problem is related to the
valve functions contained in the multi-
function valves.
If charge pressure decays in one direc-
tion the loop flushing valve may be
“sticking” in one direction.
Check control input and repair or re-
place as necessary.
Repair or replace control module as
necessary.
Interchange multi-function valves. If the
problem changes direction, repair or
replace the valve on the side that does
not operate.
Measure charge pressure in forward
and reverse. If pressure decays in one
direction, inspect and repair the motor
loop flushing valve.
System Will Not Operate in Either Direction
Check Description Action
1. Oil level in reservoir.
2. Input to pump control.
3. Pump displacement control.
4. Ensure bypass valve(s) are closed.
5. Charge pressure with pump in neu-
tral.
6. Charge pressure with pump in
stroke.
7. Pump charge relief valve.
8. Charge pump inlet filter.
9. Charge pump.
Insufficient hydraulic fluid to supply
system loop.
Input to control module is operating
improperly.
Control linkages are not secure, control
orifices are blocked, etc.
If bypass valve(s) is open, the system
loop will be depressurized.
Low charge pressure insufficient to re-
charge system loop.
Low charge pressure with the pump in
stroke indicates a motor charge relief
valve or system pressure relief valve
may be improperly set.
A pump charge relief valve that is leaky
or set too low will depressurize the
system.
A clogged filter will undersupply system
loop.
A malfunctioning charge pump will pro-
vide insufficient charge flow.
Fill reservoir to proper level.
Check control input and repair or re-
place as necessary.
Repair or replace control module as
necessary.
Close bypass valves. Replace multi-
function valve if defective.
Measure charge pressure with the pump
in neutral. If pressure is low, go to step
6; otherwise continue with step 5.
Measure charge pressure with pump in
stroke. If pressure is low, adjust or
replace motor charge relief valve, oth-
erwise go to step 9.
Adjust or replace pump charge relief
valve as necessary.
Inspect filter and replace if necessary.
Repair or replace the charge pump. If
OK go to last step.
If the above actions do not remedy the problem
contact a SAUER-SUNDSTRAND Authorized Service Center.