SCREED LIFT SYSTEM.
Table 2-5 lists common malfunctions associated with the
screed 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 2-5. Screed Lift System Troubleshooting.
TEST OR INSPECTION
SCREED FAILS TO LIFT.
Check operation of hopper lift cylinders and screed extension cylinders.
If hopper lift cylinders and screed extension cylinders operate normally, go to step 2.
If hopper lift cylinders and screed extension cylinders fail 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.
The following tests require use of a hydraulic system tester. Install tester in-line at
flow test point indicated by each individual test per TM 9-4940-468-14. Make sure
ratings of all fittings and hoses used are adequate for maximum pressures and flows
System operating pressure must be at 2475 ±25 psi (17 066 +172 kPa) before
performing this test. If pressure is not correct, refer to paragraph 2.51 and reset
system operating pressure.
Open right access door per TM 5-3895-373-10. Install hydraulic system tester for flow test at port
(1) per TM 9-4940-468-14. With screed lift switch in lift position, check for flow from stack relief
valve to return manifold at port (1).
If flow is present, replace stack relief valve per paragraph 2.44.
If flow is not present, refer to MALFUNCTION 4. AUXILIARY HYDRAULIC SUPPLY TO VIBRATION AND
CYLINDER CIRCUITS FAULTY.