TSE DPT40-B, Owner'S Manual

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Series 90 Troubleshooting 7
9. Check charge pump.
10. Check pump displace-
ment control.
11. Check system pres-
sure.
12. Check system multi-
function valves.
13. Replace transmission.
A malfunctioning charge pump will
provide insufficient charge flow.
Control linkages are not secure, con-
trol orifices are blocked, etc.
Low system pressure will not pro-
vide power necessary to move load.
Defective multi-function valves will
cause system pressure to be low.
Repair or replace the charge pump (9.2.4).
If OK go to last step.
Repair or replace control module as neces-
sary (8.2 and 9.3).
Measure system pressure (4.2). Continue
with next step.
Repair or replace multi-function valve(s)
(9.2.1).
Replace pump and motor.
7.6 Improper Motor Output Speed
Item Description Action
1. Check oil level in reser-
voir.
2. Check charge pres-
sure.
3. Check pump output
flow.
4. Check variable motor
displacement control.
Insufficient hydraulic fluid will reduce
motor speed.
Incorrect charge pressure can result
in a low speed motor.
Incorrect outflow will affect output
speed. Incorrect output flow indicates
the swashplate is out of position.
If variable motor displacement con-
trol is not functioning correctly, vari-
able motor swashplate may be in
wrong position.
Fill oil to proper level.
Measure charge pressure (8.1.1) , adjust
charge system as necessary ( 9.2.3 and
9.2.4 ).
Measure pump output flow by teeing into
outflow hose. Check for proper pump speed
and see that the pump is in full stroke.
See if variable motor displacement control
is responding. If not, repair or replace con-
trol
(9.5) .
7.5 Low Motor Output Torque
Item Description Action
Measure system pressure at motor (4.2) . If
pressure limiter setting is low, increase
setting.
Check control supply pressure (4.2.3) or
repair displacement control (9.5) . Check
motor control orifices (9.5.4) .
Check for leakage in O-rings, gaskets, and
other fittings (
9.1.1 and others). Repair unit
as required, or replace leaky unit.
Replace pump and motor.
1. Check system pressure
at motor.
2. Variable motor stuck at
minimum displace-
ment.
3. Check for internal leak-
age.
4. Replace transmission.
Low system pressure at the motor
will reduce torque.
Minimum motor displacement yields
low output torque.
Internal leakage will reduce system
pressure.
CONTENTS