TO-30 hydraulic questions/issues

bocephas

New User
Newby here. will keep this brief to get discussion started. put in piston/rings/cylinder/new o-ring at cylinder feed tube. new control valve because I broke the old one. (dont ask)new 90 wt mineral oil. lift arms will raise with no load, will not raise with load, but sure tries hard. also pto shift lever has less travel than before. cannot see why. no leaks while looking thru acces port. seems to not be fully engaging pto? why not? less-than-helpful shop manual is no help. hoping someone on this forum can. thanks
 
Sounds like the relief valve spring may be broken. If you don't see any internal leaks that would be a place to look. When the lift goes up, is it a steady lift or is it jerky? If it's jerky, there are problems with the pump valves.

As far as the pto, hard to say, but looks like you'll be going back in to correct hydraulic problems. Probably be obvious once you're in there.
 
Did you replace the relief valve while you were in there? Remove the pto cover and make sure when you install the pto cover that the pto fork on the inside of the cover inside gets installed in the notch that it goes in. It is easy to miss when installing the cover.
 
well from what I read in my shop manual,I didn"t suspect the relief valve. I had no trouble before this, and see no leakage or bubbling or swirling like the manual says there should be. Yes the pto lever is in the slot between the two flanges on the shaft. I only have half the lever movement that I originally had. I cannot see how there could BE any more movement. Lift arms raise up smoothly with no load, just shake with a load with no rise at all.
Thanks for your replies..
 
Did you check the pressure tube on the right hand side of the case? Did you remove the pump or did you replace the control valve with the pump in place?
 
(quoted from post at 08:19:47 04/16/14) Did you check the pressure tube on the right hand side of the case? Did you remove the pump or did you replace the control valve with the pump in place?


pressure tube is good. no leaks. pulled pump. did not pull relief valve. did not suspect anything there because all had been working good. only went into it it change rings on piston to stop leak down. changed out control valve because I busted old one. no binding on valve. I don't know that the back end of it stayed in place, but not much you can do about it once its installed and you move the valve back and forth. got it all out of the tractor now, still see no problems, other than not much pto lever movement(compared to before I started this job)
 
(reply to post at 13:18:53 04/16/14)

top link and quadrant settings ok. since I have the pump out I will change out relief valve. spring is not broken but could be weak I guess, or valve could be obstructed inside. checked out pto lever movement on a ford 8n and its same as mine. Still no reason for the longer throw I had before tearing it down. guess it doesn't matter now, since I now realize the shaft is only going to move so far (stop to stop ) and that's what its doing. Soon as I get an r/v in the mail I reassemble it all and try again.....
 
Presumably you are not trying to lift anything heavier that 750-800 pounds.

Are you seeing anything suspicious through the RH access hole when you try to raise a load on the three point?

Do you have full travel on the control valve(~ 1 inch fore and aft total movement)?

If there are no oil leaks in the supply to the lift cylinder or at the pump housing (leaking side plate gaskets/seals) and the control valve is moving through it"s full range, then I would expect a problem internally in the pump. Check valves?
 
Just lifting a box blade, probably less than 300#?
No nothing suspicious thru access hole, just normal minor oil swirling around pto shaft.
Yes control valve moves freely in and out, full travel.
No leaks,drips or errors. Did not suspect pump because of no problems prior to this. I have ordered a relief valve, although old one is not plugged, but spring could be weak. Had an old time Ford/Fergy man look it over and he sees no problem whatsoever. He said his next step would be r/v, same as some suggestions on this forum.
so we'll see. Appreciate all the comments and suggestions
 
well this is for those who helped me out with suggestions. Hope someone reads this. I replaced the relief valve and everything works great. The load stays up with no leak down. when I got the new rv I saw the problem right away. The new rv had the center pin sticking out about 1/8" The old one was jammed all the way in. No idea how that happened. even if the pump had been dropped, it would have had to hit right on the end of the rv.
thanks everyone for your suggestions
 
Thanks for the reply back explaining the fix. My neighbors TO20 lift is doing the same thing as yours, won't lift a heavy load.
 
(quoted from post at 04:47:33 04/26/14) Thanks for the reply back explaining the fix. My neighbors TO20 lift is doing the same thing as yours, won't lift a heavy load.

glad to help. hope thats all it is. Now that the hydraulics work, I have a stuck intake valve on #2 cylinder. Took the head off, and managed to lose 2 valve stem caps, one intake and one exhaust.
guess I need to make a new post, see if they are available.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top