Textron JACOBSEN R-311 69166, Technical/Repair Manual

Page: 201 / 402

5-38 4203781 First Edition
HYDROSTATIC POWER TRAIN
5
Figure 5-30: 2WD Traction System Test—Blocking
Disks Blocking Oil to 4WD Valve, All Wheels
Restrained
NOTE
Verify engine rpm is within specification (2800 rpm ± 50)
to ensure accurate hydraulic test results.
26. Start engine, release park brake, and run at full
throttle (2800 rpm ± 50).
27. Adjust flow lock tool (2) to allow pump to produce 15
gpm (57 lpm) in the forward direction.
28. Use the flow meter to warm the hydraulic oil. Turn the
flow meter valve (7) until a reading of 1750 psi (121
bar) or one half of the relief valve rating is reached.
Warm oil to 120–150° F (49–65° C); open valve fully
after operating temperature is reached.
29. After warming the hydraulic oil, verify flow lock tool is
adjusted to allow pump to produce 15 gpm (57 lpm)
in the forward direction.
30. Read and record no load flow.
31. Slowly close flow meter valve (7) until pressure
reaches 2625 psi (181 bar). Read and record loaded
flow.
32. Open flow meter valve (7), stop engine, and set park
brake. Return flow lock tool back to neutral position.
33. Calculate traction system leakage.
(Step 30 – Step 31 / Step 30 x 100 = Leakage
Percentage)
Is 2WD traction system leakage 10% or less?
YES The pump and front axle motor are good.
The 4WD system is faulty. (See “Front Axle
Motor Test” on page 5-42.)
NO Proceed to next question.
Is 2WD traction system leakage 11% to 20%?
YES Continue to traction pump test.
NO Proceed to next question.
Is 2WD traction system leakage 21% or more?
YES Continue to traction pump test.
34. Disconnect and remove test equipment. Install all
hoses and fittings as noted prior to removal.
35. Install and connect all components as noted prior to
test.
36. Check hydraulic oil level. Add oil as needed. (Refer to
“Safety, Operation, and Maintenance Manual” for oil
specifications.)
TN2358