TOW POINT LIFT SYSTEM.
Table 2-4 lists common malfunctions associated with the
tow point lift system that may be found during operation
or maintenance of the paving machine. Perform the
tests/ inspections and corrective actions for a particular
malfunction in order given.
This table cannot list all possible malfunctions that may
occur, nor all tests, inspections, or corrective actions. If
a malfunction is not listed, or is not corrected by listed
corrective actions, notify your supervisor.
Table 2-4. Tow Point Lift System Troubleshooting.
TEST OR INSPECTION
TOW POINT CYLINDERS DO NOT OPERATE.
The following tests may require use of a hydraulic system tester. Install tester in-line at pressure
test point indicated by each individual test per TM 9-4940-468-14. Make sure all ratings of fittings
and hoses used are adequate for maximum pressures and flows being tested.
Ensure that shutoff valves on both tow point cylinders are fully opened.
Check if both tow point cylinders fail to operate per TM 5-3895-373-10.
If both tow point cylinders fail to operate, go to step 2.
If either tow point cylinder fails to operate normally, go to step 3.
Hydraulic oil can be moderately flammable and can be an irritant to skin, eyes, and respiratory
system. Avoid prolonged exposure. Eye protection and rubber gloves must be worn when
working with hydraulic oil.
Open center top right and center top left access doors per TM 5-3895-373-10. Open left access
door per TM 5-3895-373-10. Install hydraulic system tester at outlet (2) for flow test per TM 9-
4940468-14. Check flow rate at tow point control valve outlet (2) to flow control valve outlet tee with
flow control valve fully closed, clockwise. Flow control valve is normally opened, counterclockwise,
during machine operation.
If flow is present with flow control valve closed, replace tow point flow control valve per paragraph
2.55 and repair per paragraph 2.50.
If no flow is detected, refer to MALFUNCTION 3. AUXILIARY HYDRAULIC SUPPLY TO
VIBRATION AND CYLINDER CIRCUITS FAULTY.