Textron JACOBSEN GP400, Technical/Repair Manual

Page: 163 / 354

HYDROSTATIC POWER TRAIN
4252490-Rev A 5-45
5
Figure 5-40: Right Front Wheel Motor Test—3WD
Models—Blocking Disk Blocking Oil to Left Front
Wheel Motor, Front Wheels Restrained
NOTE
Verify engine rpm is within specification (3400 rpm ± 50)
to ensure accurate hydraulic test results.
8. Start engine, release park brake, and run at full
throttle (3400 rpm ± 50).
Figure 5-41
9. Adjust flow lock tool (2) to allow pump to produce 7
gpm (27 lpm) in the forward direction.
10. Use the flow meter to warm the hydraulic oil. Turn
flow meter valve until a reading of 1000 psi (69 bar)
is reached. Warm the oil to 120–150° F (49–65° C);
open valve fully after operating temperature is
reached.
11. After warming the hydraulic oil, verify flow lock tool is
adjusted to allow pump to produce 7 gpm (27 lpm) in
the forward direction.
12. Slowly close flow meter valve until a reading of
2500 psi (172 bar) is reached. Read and record
loaded flow.
13. Stop engine, apply park brake, and return flow lock
tool to the neutral position.
14. Calculate right front wheel motor leakage.
(Step 14 of previous test – Step 12 / Step 14 of
previous test x 100 = Leak Percentage)
Is right front wheel motor leakage 10% or less?
YES The right front wheel motor is good. Proceed
to step 15.
NO Proceed to next question.
Is right front wheel motor leakage 11–20%?
YES The right front wheel motor is marginal.
Additional testing is required. Proceed to
step 15.
NO Proceed to next question.
Is right front wheel motor leakage 21% or more?
YES Repair or replace right front wheel motor.
See “Wheel Motors” on page 5-57, then
proceed to step 15.
15. Remove blocking disk from location (1). See
Figure 5-38. Connect hose back to tee fitting.
TN3105
2
TN3947