Ford 1920 3 point lift oscillating

[double hunter]

New to me Ford 1920 lift problems, when the lift is at any position it oscilates, it will go up to that point and drop back, go back up and drop back, about a quarter of the the way, doesn't matter if all the way up or half way up, check the fluid and changed the filter, no help, are the pumps hard to workon, any help appreciated.

 

[Soundguy]

sounds like leakdown and circuit regen. does speed change at different rpms and loads?

 

[double hunter]

The higher the rpm the faster the oscillations, the lift comes up slower than i think it should with no load.

 

[Laneman]

I have this problem on a Massey 40 I'm restoring, I have read that this is usually caused by worn or broken piston rings on the hydraulic pump. Not sure how similar the Massey pumps are to Ford, but I've seen rebuild kits that look identical for both makes.

 

[JC-jetro]

1920 has a gear driven hydraulic pump and has no reciprocating piston.

JC,

 

[double hunter]

do you think that I just need to replace the hydraulic pump or could something else be causing this.

 

[JC-jetro]

when you say oscillates it has to follow a frequency. does it happen at any given lift point? does it happen as max lift? if the pump was bad completely then lift arm would not come up. I'm thinking it might be max height lift adjustment, pressure relief mechanism failure or a check valve at the lift cylinder head causing it to burp( lose pressure and drop) and right away pump building pressure raising the lift arm. Need a more detailed description to may be pin point the problem better.

JC,

 

[Soundguy]

I have this problem on a Massey 40 I'm restoring, I have read that this is usually caused by worn or broken piston rings on the hydraulic pump. Not sure how similar the Massey pumps are to Ford, but I've seen rebuild kits that look identical for both makes.

a massey 40 and Nh 1920 are so different that virtually nothing will cross over...

 

[Soundguy]

do you think that I just need to replace the hydraulic pump or could something else be causing this.

i think you need to stop guessing and going off on tangents like repalcing the pump and focus on getting a service manual and trouble shooting the issue before you spend way too much time and money on this.

does the lift drop when you shut the machine off?

is there a point in the positiuon control travel that the oscilations stop?

we are looking for control valve and cyl / piston realative positions.. and condition of hte oring / cyl bore.

there are other possibilities like check and or safety /relief valves too.

 

[double hunter]

I'd be the first to admit I don't know jack about this, don't mind trying anything, the oscilations accur at any height, 1/2 way up, all the way, doesn;t matter, the lift arms come right up but wherever yu stop the lift the oscilations start, might ought to invest in a maint. manual
t

 

[double hunter]

Just an update on this, the o ring on lift piston is toast, have the new oring on the piston, now to just figure how to get the new gasket over the cylinder, got to be a trick as the gasket fits but will not slip down over cylinder wall.

 

[JC-jetro]

Just an update on this, the o ring on lift piston is toast, have the new oring on the piston, now to just figure how to get the new gasket over the cylinder, got to be a trick as the gasket fits but will not slip down over cylinder wall.

Look at the link below and somewhere you find how to do it. in general you get one chance to do it. Screw it up and you'll be buying another seal. Check the orientation of the double lip on the seal. The lip will face the lift piston head assembly. The seal is nylon. make sure the piston is clean, put lube oil (hyd oil) liberally on it, soak the seal in the oil, put the piston facing up on work table , keep the seal with the lip up square and plumb over the piston and slowly try to push it over so it slides in the groove in the piston. Don't force it, don't pry it, don't use any tool to do it. Do it only by hand pressure. if you have time I'd take a small container, put some hyd oil in it (1/4" deep) and leave it in sun for 1/2 hr. The heat will expand the seal just slightly that might make the job easier. I have done without heating the seal.

JC,

http://www.tractorbynet.com/forums/...ng/90819-my-f-1700-testing-my.html?highlight=

 

[double hunter]

I've got the o ring on the piston, I am having trbl getting the head gasket on, the cylinder is still connected to the head and opening in the gaskat will not slide down over the cylinder, does the cylinder come off the head, I noticed in the pictures the cyl is not connected to the head,, I may not be explaing this right.

 

[JC-jetro]

I've got the o ring on the piston, I am having trbl getting the head gasket on, the cylinder is still connected to the head and opening in the gaskat will not slide down over the cylinder, does the cylinder come off the head, I noticed in the pictures the cyl is not connected to the head,, I may not be explaing this right.

Yes, remove anything that might be attached to the 3 point, left the arm up manually(raise it) , put a 2x4 under the lift arm or tie it up there to something. that motion will move up a ram rod that pushes the piston up. This way was the most efficient way to take out head, cylinder and piston as a whole assembly to be separated outside of the tractor. too late for you doing it that way. push your arm in the cylinder all the way to the bottom and grab the end. you shuld be able to pull it out without much effort. If the o-ring is moving on you, put a small dab of rtv blue in the groove , put the o-ring in , let it dry out(cure ) for 10 minutes and then assemble the whole thing. O-ring will stay put.

JC,

 

[double hunter]

Got it all back together this morning, hooked up the disc and it worked great, lift held at all levels with no hiccuping, took the disc off and drove back to shop and was just working it up and down and now it will only work using the draft control lever and it only lifts when the lever is up past the normal operating range

 

[double hunter]

Houston, we have lift off, I hope this is last chapter in this saga, the original trouble was repaired with a new O ring on the piston in just a few minutes, the rest was a self inflicted wound, I had the sheet metal off in prep for a paint job, whatever you do DO NOT move the the 3 point lever lower than it is supposed to go with the sheet metal on, if you do it will in turn cause the wobbling pin to jump out of a pre-engineered slot and jump up behind another internal lever causing the lift not to work, it is hard to see and determine where its supposed to go, another good thing NOT TO DO is take a dowel and push the plunger in the in the control valve in while the engine is running, (trying to determine what causes oil to come to the piston), this will in turn release a small flood of oil, covering you and your assistant((grandson) and everhting forward from that point to be covered with oil. I didn't know jack when I started this and now I know just e-nuff to be dangerous, but it is lifting.

 

[JC-jetro]

Houston, we have lift off, I hope this is last chapter in this saga, the original trouble was repaired with a new O ring on the piston in just a few minutes, the rest was a self inflicted wound, I had the sheet metal off in prep for a paint job, whatever you do DO NOT move the the 3 point lever lower than it is supposed to go with the sheet metal on, if you do it will in turn cause the wobbling pin to jump out of a pre-engineered slot and jump up behind another internal lever causing the lift not to work, it is hard to see and determine where its supposed to go, another good thing NOT TO DO is take a dowel and push the plunger in the in the control valve in while the engine is running, (trying to determine what causes oil to come to the piston), this will in turn release a small flood of oil, covering you and your assistant((grandson) and everhting forward from that point to be covered with oil. I didn't know jack when I started this and now I know just e-nuff to be dangerous, but it is lifting.

Goods news :thumbsup: Glad it worked out and the fix was simple and cheap. I'll have to take time and decipher what all happened as you explain at a later time.
It is good to be jack of all trades... and master in none stay safe.

JC,

 

[Soundguy]

ditto1 glad you got it going!

 

[jinman]

Double hunter, you learned the way most of us do. Sure, you made a few mistakes, but you solved the problem. I think that learning method describes 99.9% of all TBN users. The remaining .1% have never tried and never will.

 

[Soundguy]

Double hunter, you learned the way most of us do. Sure, you made a few mistakes, but you solved the problem. I think that learning method describes 99.9% of all TBN users. The remaining .1% have never tried and never will.

yep! how's the saying go.. you gotta break a few eggs to make egg salad?