Procedure for Wheel Motor Efficiency:
Note: Over a period of time, a wheel motor can wear internally. A worn motor may
1.Make sure hydraulic oil is at normal operating tem- perature by operating the machine for approximately 10 minutes. Make sure the hydraulic tank is full.
2.Park machine on a level surface with the attach- ments lowered. Make sure engine is off and the parking brake is engaged.
3.Read Precautions for Hydraulic Testing.
4.Make sure that traction pedal is adjusted to the neu- tral position (see Adjust Traction Drive for Neutral in the Adjustments Section).
5.Attach a heavy chain between the rear of the ma- chine frame and an immovable object to prevent the ma- chine from moving during testing.
6.Install hydraulic tester (flow meter) using the same tester connections as TEST NO. 1: Traction Pump Flow.
Make sure the tester flow control valve is fully open.
7.Make sure parking brake is engaged. On machines with 3 wheel drive, chock the front wheel to prevent front wheel rotation.
8.After installing hydraulic tester, start engine and run at low idle speed. Check for hydraulic leakage and cor- rect before proceeding with test.
CAUTION
Use extreme caution when performing test. The drive wheels will be trying to move the machine.
9. Move throttle to full speed (3150 + 50 RPM).
10.Slowly push traction pedal in the forward direction until 1000 PSI is displayed on the tester pressure gauge.
11.With all drive wheels locked (not rotating), total in- ternal leakage for all wheel motors will be shown on the flow meter. Flow should be less than 2 GPM (7.6 LPM). Record test results.
12.Release traction pedal and shut engine off.
13.If specification is not met, individual wheel motors need to be removed from the traction circuit to deter- mine which motor(s) is leaking excessively.
A.For SP2020/3020 machines, a wheel motor can be removed from the traction circuit by disconnect- ing and capping the two hydraulic lines at the motor.
B.For SP5020 machines, the front motor can be re- moved from the traction circuit by disconnecting the two hydraulic lines at the motor and then connecting the hoses together to allow flow to the rear wheels. A rear motor on a SP5020 can be removed from the traction circuit by disconnecting and capping the two hydraulic lines at the motor.
14.After removing a motor from the circuit, retest using steps 6 through 10 making sure that the remaining drive wheels are locked (not rotating) during testing. When a worn motor is removed from the traction circuit, the test results should show a decrease in leakage flow from the system. Any wheel motor that has leakage greater than
.7 GPM needs to be repaired or replaced.
Example: consider a SP5020 that has a total internal leakage of 3.5 GPM. When the right, rear wheel motor is disconnected, the system leakage decreases to 1 GPM. The leakage for the disconnected motor is 2.5 GPM which indicates the need to repair or replace the right, rear wheel motor.
Multiple wheel motors may be worn, so efficiency testing of all wheel motors may be required. After an individual motor is tested, reconnect that motor before proceeding to test another motor.
15.After testing is completed, disconnect tester from machine and reconnect all hose connections.
Hydraulic | Systems |
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Sand Pro 2020/3020/5020 | Page 4 – 27 | Hydraulic System (Rev. A) |
