hi i think u will find the conection block above the operater head , which the tilt hoses connect too has a crack in it , carry out a pressure test to confirm
one way that you can differentiate between the cyl's and valve is to install a small ball valve on the front hose of one of the tilt cyl's. (some times the bypass does not uccur at the end of the stroke) you dont have to buy a 3000 psi valve to do this as you are not going to dead head long enough to cause a rupture, so usually $20.00 buys a valve and fittings to fit right in line. install it, tilt (about half way) back and close the valve. oil has to transfer between the cyl's for the mast to drift. no drift = cyl's...drift = valve.
I would first check cyl. bypass by deadheading tilt cyl`s all the way forward. remove the hoses from the front of each cyl. then continue tilting forward. there should not be any oil coming out. also try it by tilting back and removing the rear hoses. this is the easiest way that i know to eliminate the tilt cyl`s from bypassing. if cyl`s are ok, then check the tilt lock in a similar mannor (if equipped) then move on to the control valve.
No offense jerry g, my experience with fork lift trucks ( 22 years ) we have had little to no luck with used parts.
Sometimes you do get very lucky, but the majority of the time when you roll the dice you lose.
For the stress and aggravation try to go rebuilt or new.
Did a qualified tech reseal the tilt cylinders and install the valve control???
Now with that said I would get a pressure check valve tool to install in different locations to test pressure drop.
Check and double check the simple things first. You will be surprised
Yes the hydraulic control valve was used, but was working good in the last truck it was in. Is their any valves that are associated with this system that we need to be looking at?
when you swapped out the control valve was it used or rebuilt???
someone messed up on the cylinder rebuild