1970 2520 three point settling fast

[cantbeatadeere]

Hey Guy's, my three point will settle from full up to the ground within a couple hrs. with no load on it. I have honed the cyl. and replaced the o-ring on the rockshaft piston and it still settled, removed the return valve and checked the spring/valve and all looks mint. the Tech-manual says under the "excessive settling" section to check for weak or broken return spring(looks perfect), return valve leaking(also looks perfect), pressure metering shaft wear(again.. perfect), rockshaft piston O-rings(new)..........Now for the million dollar question.-- is the relief valve and the "thermal" relief valve one in the same?? and what check valve would they be talking about. those are the last couple things to check and I cant find either one in the manual under the rockshaft section..............any input would be great. thanks

 

[Tx Jim]

Are you reading a JD tech manual or IT tech manual? It's been a long time since I looked inside a JD tech manual but I was thinking there should be an answer to your question in the JD tech manual.. I think thermal relief & relief are one in the same. If it was my tractor and 3 pt settling was an issue I'd replace every spring on each RS valve. I suppose you have checked valve components(parts keys 29-32)?

 

[cantbeatadeere]

Hi Jim, the picture you posted, I have that assembly completely apart and it all looks great -1700 hrs. on this tractor- I am moving to the valve assembly by the hyd oil filter and checking the relief valves there for problems, broken spring or possibly a contaminant of some sort.........thanks for the input you are always a big help.

 

[cantbeatadeere]

I FOUND IT!!!!!----the smoking gun causing the problem was a piece of thin metal(looking in the parts manual for the piece) approx. .25 wide x .5 long stuck under the flow control valve -- #7 in Jims diagram. gaskets should be here tomorrow, everything is cleaned and ready to go back together.

 

[jd110]

I doubt that debris under valve 7 would cause settling. That valve controls speed of lift. The relief valve and thermal relief is the same part and very likely is your problem. I would replace the spring, ball, and seat while it is apart anyway. Valve clearance adjustment can cause settling also.

 

[cantbeatadeere]

That did it --- was dropping 7-8 inches in an hour. has been setting for about an hour now and has not moved at all. this also fixed my idle problem, the tractor would labor badly at idle, even stall unless the three point was all the way down. now idles at 700ish at any setting............sweeeeetness.-----

 

[Tx Jim]

Thanks for update & I'm glad you got it repaired.
Jim

 

[cantbeatadeere]

here is the metal piece that was stuck in the valve.....dime is for scale....

 

[Tx Jim]

Metal piece doesn't "ring any bells" with me.

 

[cantbeatadeere]

I quite literally was up at 2 a.m. on a mission to find a piece in the parts manual that looked even slightly like that, there was nothing. everything on the tractor works perfect now and I am pleased with that, guess I will just chalk it up as a mystery????