7020 diff lock/pto issues

Hello all, new to the forum. Have been reading for a couple years but no posts. Bought a 7020 black belly a couple years ago. Currently around 5700 hours. All was fine until baling couple days ago. PTO quit spinning under a load. Started by not staying engaged without wiring it on, then wouldn't even run under load of baker. Plenty of fluids. Tapped on the sleeve on bottom PTO port as mentioned in another thread. Now will spin but when running baler still won't hold.
Also, to make this happen, I have to wedge something under diff lock pedal to keep it disengaged. I know diff lock can kick the PTO off per another thread. All I want is for my PTO to run and for Diff lock to disengage when I want it to.

I appreciate all the help in advance and if you need more info to help dissect my problem please let me know.
Have a good rest of your Saturday.

Does every thing work with a remote valve pulled? If it does, add a shim or two to low pressure compensator.   MACK

Remotes work fine with PTO on or off. Still have to hold PTO lever forward to get it to spin. Can you go into a little more detail on shims on the low pressure compensator? Haven't found anything to test pressures yet. Hoping I can figure out the shims and that takes care of it. Need to cut another 50 acres soon.

While holding remote back, does PTO stay engaged?
On front corner of piston pump is a block bolted to pump with four bolts and one small line. Sticking out toward battery is two plugs. One takes 1 1/8 socket the other 1/2 . Take the 1/2 plug out along with shims, spring, and spool. Check for broken spring. Add shim to bring pressure to just under 600 PSI.    MACK

Couldn't wait to fiddle with the tractor again so ran out before I had to go to work. Fired it up and turned engaged PTO. It would not stay engaged. I wedged a bolt underneath the Diff Lock Pedal to keep it up and it seemed like it wanted to stay engaged but would kick off. (The baler is attached, if that matters).

Ok. Got out early again and tore into the compensator. I pulled the 1/2" plug out. This time, it came with the shims and the stop. I got the spring out as well. It had a piece of something wedged in the spring. I'm assuming this was the main culprit. Got it out, put everything back together, fired up the tractor, and the PTO held with the baler attached. 

Ok. 

You have established a good (600 psi) stand-by pressure at the PTO valve tee. It appears the oil pressure/flow isn't getting beyond the tee.  600 psi goes from the PTO valve forward to the diff lock valve and then onto the brake valve thru steel lines. Your brakes have to be affected by this. I've never had to take a PTO valve apart. Never had an issue with one. If you check pressures at the PTO clutch/brake ports, I'll bet you have very little pressure. The problem must be in that PTO valve somehow not allowing oil flow to move on downstream to Diff lock and brakes.

Are you talking about one of the nuts on the pto pump?

I've got two gauges in my truck now. Going to test this afternoon. Manual says if one is low, it's excessive leakage in that compartment only. If both are low, it's a problem in the pressure reducing valve or a leak downstream. No noticeable external leaks in the system as far as I can tell. Next issue, the plug labeled 1 on the drawing, figure 168 in the shop manual, is back into the body too far and can't get a wrench on it. Would this be part of the problem possibly? Could this be what tornado was talking about in tightening the spool?

Spoil in top port of pto valve came out in a bunch of pieces. Think I found the problem

Ok. Replaced the piston in the top port of the PTO pump. Cleaned out the other 2 ports. Everything else looked good. New gasket, bolted everything back together. Fired it up. Had slightly over 300 PSI in the left (I think) port. Went to engage the PTO and it wouldn't hold and actually wouldn't barley pull forward. This time, I believe the linkage was bound up. Tried to shorten it up and the damn thing broke. Have a new one ordered and should have it on tomorrow. I've definitely got my fingers and toes crossed that the problem is solved. PTO doesn't spin freely now either. Hoping shes ready to make some hay Sunday after the rain goes by. Just wanted to update everyone that has lent a hand in my repairs. As always, I appreciate it. 

MACK, any ideas?

Edited by Basehorhawk - 22 Jun 2017 at 9:54pm

I think a lot of things were done to it before I got it. Never considered lines being hooked up wrong. I'll try and get into the book tomorrow to see what I can figure out. Appreciate it.

I never noticed it until recently, but that doesn't mean it's a new problem. Haven't had a chance to check lines yet. I'm not sure if it is working or not with pedal down. All I know is it pulls down when you let off the breaks, think the dang things possessed.