Ford 2000 lift hiccup

[Fordman1981]

I have a 1970 ford 20000 diesel and the lift will raise all the way fine but when its left at the top it bobs or hiccups. the lift will also drop if I go over a bump and it jars the lift lever which seams really touchy to me. I have read on previous post that u can rebuild the lift piston under the tractor seat. The question I have is it the piston that is doing this or could there be another culprit. I would like to know before i tear into the hydraulics.

Thanks

 

[whodat526]

it could be a number of things from the filter being partly plugged, to the piston seals leaking by, or the control valve or unload valve trying to stick. u really cant tell until u tear in to it and if u buy a lift top kit i will come with all the seals and orings need to rebuild the lift top and u can inspect the filters then.

 

[Fordman1981]

thanks whodat for the information... so if I get a top lift rebuild kit it will pretty much replace anything that could be causing the problem except maybe the filter?

 

[whodat526]

right it wont come with the filter but best to change both of them while u have it apart

 

[Soundguy]

the filter is the last thing I'd check.

a touch lever that moves over a bump tells me his friction disc is worn, missing or loose.

the bobbing at the top indicates a leak in the pressure side that makes for a leakdown, then circuit regeneration.. usually I would think this leak is past the check valve.. ie... between the check and the lift cyl.. as anything before the check would make less of a difference due to pump volume... anything leaking past the check will cause the lift to drop.. if the lift drops and the position control lever hasn't, then the unload valve will regenerate the circuit and move the arms back up.. thus the up/down motion.

cyl to piston area could be a leak, as well as safety / check valve.. or any orings in the high pressure side... finding the leak is where I'd start.. and that would start with a visual inspection and a flashlight, and perhaps a small 1" round telescoping mirror.

soundguy

 

[whodat526]

yea i would check the friction disk on the lift handle i wasn't even thinking about that in my first post

 

[Fordman1981]

ok the friction disk is on the lever itself?

 

[Fordman1981]

also as far as a leak i did have a leak at the pump up on the bellhouseing /engine i tightened the nut and got that leak to stop. i have the tractor parked in the building looking for any type of leak none found so far.

 

[Soundguy]

please go do yourself a favor and get a service manual for your machine.

the leak in the high pressure side of the circuit after (including) the check valve ) will all be INTERNAL under the 3pt lift cover.. not external.

and yes.. the friction disc is right on that big ole handle you use to raise your implement.

follwo the handle down thru the quadrant till it gets to the round base.. behind that base will be a ruberized cork friction disc.. or about a 3/16" space where one used to be, sandwiched up to the quadrant housing.

the nut/tension spring holds the 3pt lift handle and base against the friction disc and against the quadrant housing.. your's is real loose, worn or gone if it moves by itself when you hit a bump.

if you don't have a master parts catalog and service manual ( and owners manual ) which i HIGHLY reccomend.. at LEAST hit the NH parts site and look at exploded diagrams of the hyd top cover and center sections.. etc.

soundguy

 

[Soundguy]

here.. i'm doing your work for you.

now all you have to do is supply the wrenches and sweat and some eyeball work and some gaskets, orings and whatnot...

part # 32 in the first pic is the friction disc...

soundguy