White 2-135 III 3 point problem

[Mitch Poindexter]

The 3 point arms on the 135 have quit. Theyre down and will not come up. Linkage is all ok. Do I need to pull the top off the rear end and take a look, or should I start somewhere else? This tractor is used everyday and has always worked fine.
 

[B A Star]

   It's a simple control system that is on or in the plate under the top cover.  First, there is a raising rate restrictor valve on the left hand side, someone hasn't turned the valve all the way in?  There is a three point hitch relief valve that is under the plate to relieve any shock loads. Make sure it is in place (elbow could be broken off).
   The control valve (servo valve) is bolted to the top of the plate.  It has a spool valve that is operated by linkage. It also has an interlock system, however that would not keep it from raising.  How do you know the linkage is all hooked up?  You have not had the top cover off from your inquiry.
 

[Mitch Poindexter]

Took cover off this afternoon, all linkage is hooked up. Took the servo valve apart, no clogged passages. 4 link system that hooks the external arm to the control spool looks to me like it could get out of whack if not careful and operate the system in reverse. Is it possible that we had the 3pt down than bounced it somehow and now the 4 link inside is working backwards?

As it stands now, when I position the control arm in the raise position, the control spool is released. To me, that should be the lowering position letting oil return to the reservoir. Am I thinking about this backwards, or do we have the internal linkage backwards?