Currently troubleshooting an issue with an inching valve that 2 other techs have have potentially caused, making square 1 difficult. The valve body was disassembled, and upon reinstall action, the guy couldn't get the inching working properly, so he cut the stop bolt, and rigged the valve so depressing the pedal would allow the spool to fully extend, and pressure would operate forward and reverse. Because they pedal was depressed to operate, he disabled the brakes.
I'm trying to return the unit to OE service, and here's my trouble- with the stop bolt in place on the inching valve, the the spool relieves pressure in the spool head when the spool travels forward. When the pedal is released, the spool head comes back in to hit the stop bolt. What is the proper function causing the resting pedal to return the spool back into operating pressure for forward and reverse?