TM 5-3805-260-24
2. Run the engine at any rpm with the system
pressure at 0 to 100 psi.
3. Write down the oil temperature.
Find the leakage rate of the cylinders and the
leakage rate of the control valves. Use the test
information from the System Tests, Pump Test and
Blocked Cylinder Tests.
Example: Find the leakage rates in the RIGHT
TURN position.
Test 15: flow rate of the pump only.
Test 27: flow rate of pump and control valve.
Test 4: flow rate of pump, control valve and
cylinders.
The system components tested in Tests 15 and 27
are the same except for the control valve. Then the
difference in flow rates must be the leakage in the control
valve (take the test information for Test 27 away from the
test information for Test 15).
The system components tested in Tests 27 and 4
are the same except for the cylinders. Then the
difference in flow rates must be the leakage in the
cylinders (take the test information for Test 4 away from
the test information for Test 27).
Make a comparison of the test data with the data on
Chart C for the specific machine under test. The
information on Chart C is the maximum for best
performance.
Troubleshooting
PROBLEM: Tests 27 and 28 give an indication of
leakage in one or more of the cylinders.
PROBABLE REASON:
A. Leakage in only one of the cylinders.
B. Leakage in both cylinders.
RECOMMENDATION FOR ACTION:
Do the Blocked Cylinder Test for cylinders on the right
side.
PROBLEM: Test 27 and 28 give an indication of
leakage in
the valves.
PROBABLE REASON:
A. Leakage in the relief valve.
B. Wear or damage in the valve body or valve spool.
C. Hand metering pump, unloading valve, selector
valve or diverter valve is worn or not working correctly.
RECOMMENDATION FOR ACTION:
A. To find the leakage on machines with
supplemental steering, use a Blocking Plate
Assembly between the diverter valve and the
control valve for steering.
B. Inspect the components of these valves to find
the problem.
Right Side Cylinders Blocked
If the Blocked Cylinder Tests gives an indication of
leakage that is too high in one or more of the cylinders,
do the Blocked Cylinder Tests for the Right Side. For
best accuracy, turn the steering wheel through several
cycles to get the temperature of the oil in the cylinders
the same as the temperature of the oil in the hydraulic
tank. Make the temperature of the complete system
150° F.
1. Install the safety link.
2. Lower all implements to the ground.
3. Stop the engine.
4. Move the steering wheel from RIGHT TURN to
LEFT TURN several times to release any
pressure oil in the cylinder lines.
5. Move the steering wheel back to center.
6. Remove the cap for the hydraulic tank to release
any pressure and tighten the cap again.
7. Put a Blocking Plate Assembly in the rod end of
the right steering cylinder.
Test 34: System Oil Temperature
1. Open the manual load valve fully.
2. Start the diesel engine.
3. Run the engine at any rpm with the system
pressure at 0 to 100 psi.
4. Move the steering wheel to the RIGHT TURN
position.
5. Write down the oil temperature.
Test 35: STEER RIGHT Flow Rate
1. With the manual load valve fully open, move the
steering wheel to the RIGHT TURN position.
2-123
