o Set the MASTER switch to the ON position and turn on the primary
or backup hydraulic system.
Manually operate the conveyor
directional control valve in both directions (Fig. 39F). If the
directional control valve does not operate the system in both
directions it must be replaced. If it operates correctly in both
directions, activate the directional control valve using the
direction control switch on the hydraulic control panel (Fig.
39F). If the switch fails to activate the directional control
valve, you must troubleshoot the electrical system.
lesson will continue with troubleshooting the upper rear door system.
Upper Rear Door Hydraulic System.
The general troubleshooting requirements also apply to this sub-system.
The following are specific items that must be checked prior to
troubleshooting the upper rear door hydraulic system.
o The lower rear door is open and properly secured.
o Correctly adjust the flow control valve (TM 9-2350-267-10).
o Fully close the dump valve (turned fully clockwise).
o Inspect the door and door hinges for damage or binding.
There are three problems to troubleshoot the upper rear door system for:
o The door does not go up or down.
o The door will not remain in the open position.
o The door opens or closes roughly.
The first problem to troubleshoot is the door does not go up or down.
o Inspect the hydraulic actuator, oil lines, tubes, fittings, and
hoses for signs of leakage. Repair or replace as required.
o Check the hydraulic control panel pressure gage.
indicate between 100 and 300 psi without system load. Operate
other hydraulic systems; if low pressure is