4-46. Dual Over Center Valve.
This task covers:
General Mechanics Automotive Tool Kit
Bay removed (para. 2-16).
(Item 1, Appendix B)
Hydraulic Test Equipment
Antiseize Tape (Item 19, Appendix E)
There are two dual over center valves on transporter. The maintenance procedures are the same for both.
a. Test. (figures 4-51 and 4-52)
Dual over center valve removed for test. See para. c. below.
Connect a 0-6,000 psi (0-41,307 kpa) hydraulic pressure source and gage to a cylinder port 2.
Connect a 0-300 psi (0-2,068 kpa) hydraulic pressure source and gage to cylinder port 1.
Connect valve port 2 to hydraulic reservoir and 0-30 GPM flow meter.
Plug valve port 1.
Set pressure at cylinder port 2 to 0 psi (0 kpa).
Increase cylinder port 1 pressure in 50 psi (345 kpa) and record the pressure at which flow occurs between
cylinder port 2 to valve port 2.
Increase cylinder port 1 pressure up to 250 psi (1,705 kpa) or until flow occurs between cylinder port 2 and
valve port 2 at 0 psi (0 kpa).
Adjust valve (see para. b. below) if valve does not perform within tolerances.
Reduce all pressures to 0 psi (0 kpa) and disconnect connections.