NOTE: The test can be performed at either line between the pump and the motor. The top line on the motor is the in line from the pump when driving forward. The linkage has more travel in forward than it does in reverse, so the test is most easily done on the top line of the pump, driving the pump in the forward direction for- ward.
4.11.Connect the flow meter end of the test kit to the hydro motor.
4.12.Remove the plug from the line coming from the outboard port on the hydro pump. Use the 18” test kit line to connect the pressure gauge end of the hydraulic test kit to the line coming from the hydro pump. See Figure 4.12.
Figure 4.12
4.13.Tighten all the fittings.
4.14.Insure that no unsafe conditions will result from starting the engine and operating the drive sys- tem.
CAUTION: The technician will be exposed to moving parts during this procedure. They should not reach past or around any moving parts during this test, nor should they place themselves in any position where a loss of foot- ing or balance might bring them into contact with rotating components. Loose hair or garments should be secured to avoid the possibility of entanglement with rotating components.
M48 Tank
4.15.Remove the stop bolt that sets the end of the travel of the lap bar that controls the hydro pump to be tested. See Figure 4.15.
JAM NUT
STOP BOLT
Figure 4.15
4.16.Confirm that the valve on the test kit is fully open.
4.17.Start the engine and purge the hydraulic sys- tem as follows:
4.18.Cycle the lap bar from full forward to full reverse 5 times at 10 second intervals.
4.19.Close the relief valve on the hydro pump and repeat the cycling process to purge any remain- ing air from the system.
4.20.Check for and repair any leaks.
4.21.Check the fluid level in the hydraulic reservoir. Top it up if necessary.
4.22.Continue to operate the drive system to
NOTE: Performing the test with cold fluid will make a significant difference in the flow readings obtained. The test will not be valid.
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