how to trouble shoot 3 point hydralics

mit · May 24, 2007

can any one help with trouble shooting a 3 point hitch hydralics system.lets say 1. there is fluid
2. the fel hose is connected on the hydralic line.quick connectors.
3. with the engine started and the lever moved to the up position it does not lift.
what to check next?

JerryG · May 24, 2007

I have learned over the years that the first thing to check when having a hydraulic problem is always the quick disconnects. They can look like they are connected and not be. Some times you have to take them apart and put them back together to find out that they weren't together right to start with.

YanmarFever · May 25, 2007

Mit, Im willing to help you if you call us, otherwise I type like a turtle.

I have trouble shot a few mitsus that would not lift
you can find us at

Used Yanmar tractors, New Mahindra tractors, New Branson Tractors from Ernie's Imports inc

Ernie

mit · May 27, 2007

i have in the hydralics jd20 fluid. it is full. i tried air pressure at the rear vent hole with tractor on and off while working the lift lever back and forth. it still will not lift. i opened the pressure relief valve that is near to the gear shift and crank the engine. fluid came out of one of the holes. i blow out the pressure relief valve with 100lbs air so it is clean. put it back together it still would not lift.any help would appreciated.

mit · May 27, 2007

oh i took off the quick disconnects and blew air through so there is no restriction all the way to the pressure relief valve. i think that the pump is fine cause i put my thumb over the hole while cranking and it blew fluid .i dont know what else to do. i was told to change the fluid to a thicker oil but i dont think that is the problem.

wushaw · May 28, 2007

Well there is one thing you can try is take the top of the three point housing off to see if it has a frozen piston or broke piston. I am grasping at straws here ....although on my 372 the 3pt would not come down once and it turned out the piston was froze in the up position.

mit · May 28, 2007

i blew air into the hydralic line. the line that carries fluid to the control valve and the lift piston. i can hear the air gushing out.there is no back pressure.its like if the pressure is diverted from the piston. i have read that the control valve could get stuck in a neutral position.in this position the pressure or oil gets dumped back into the resovour.

wushaw · May 29, 2007

Control valve stuck in the neutral position sounds like it could be.

mit · May 29, 2007

i pulled off the reservoir and took off the control valve. i blew air into one of the holes and it is coming out of the poppet valve discharge outlet with any position of the control lever.i unscrew the poppet valve.the big nut with no hole and remove the spring and the piston. the piston was a little tight to come out i found a piece of crud on it. i cleaned and replace poppet valve,spring and tighten down.then i air tested .when the control lever is pushed in air comes out the second hole and when released the air comes out of the poppet valve discharge.dont know if it will work on the tractor as yet but it seems to be working the right way now.thank you all for your help.

mit · Jun 6, 2007

so my 3 point hitch works. it goes up and down and all the in between positions.do any one know how to make a home made carry all to attach to the 3 point hitch?made from wood and bolts?

mit · Jul 14, 2007

y no comments here?

lens12 · Jul 15, 2007

Is this a new installation that isn't working or did it work & quit now quit working?

mit · Jul 23, 2007

WHEN THE TRACTOR ARRIVED THE HITCH WAS UP. I PUSHED THE LEVER DOWN AND STOOD ON THE HITCH AND IT WENT DOWN.THEN I PULLED IT UP AND THE HITCH DID NOT GO UP. IT IS GOOD NOW THOUGH.I JUST NEED TO HOOK UP SOMETHING TO IT THAT I CAN USE.

diyDave · Jul 26, 2007

mit said:
oh i took off the quick disconnects and blew air through so there is no restriction all the way to the pressure relief valve. i think that the pump is fine cause i put my thumb over the hole while cranking and it blew fluid .i dont know what else to do. i was told to change the fluid to a thicker oil but i dont think that is the problem.

Please don't do this- Death by hydraulic fluid embolism is SO painful!

mit · Jul 26, 2007

how would u know?u are still alive to talk about it.hey and my hitch works .

oliver28472 · Jul 27, 2007

Mit, what he is talking about I think is hydraulic fluid entering your blood stream under high pressure. It's always a bad thing and same applies to diesel. So if you a leak somewhere on your tractor that is under pressure don't hold your hand over it to see how bad it is. There are probably some horror stories on the safety forum about this.

mit · Jul 27, 2007

i thought so.the koyker instruction said something like that, when looking for leaks in hi pressure systems the pressurized fluid could penetrate your skin.you should put a card board at the point where u suspect a leak not your hand.my thing was if he knew of a better way y not post it so a novice like me will not repeat such a mistake. it would have been worse it while the tractor was running u try to disconnect a pressure hose connection.i just posted what i did to make my thingy work in the hope of helping some one with a similar problem.hey so i was wrong on that one .keep your hands away from pressurized fluid just stay back and look for flow with a quick crank.hows that?i am not a pro but i think the fine spray under hi pressure is what he meant.bottom line is b careful when working with hi pressure systems

oliver28472 · Jul 30, 2007

Amen brother.

mit · Oct 27, 2007

some helpful pictures on the hydralics.

diyDave · Oct 27, 2007

Mit- Back in July, when I made the other post, I also made another post, which I don't see now. Maybe one got dropped when they invented this section of the forum this summer. Anyway, sorry for the wisecrack, just my nature, trying to have fun at another's expense. With regard to your diagrams, I would take the control valve in the first diagram apart, carefully, as the springs inside can sometimes cause the assembly to pop apart, losing parts in the process. First thing to do is to bleed off all pressure from the system, by shutting off the tractor, and cycling the valve handle back and forth. Then remove any hoses connected to the valve, and dis-assemble one component at a time. Check for sludge buildup, broken springs, plungers that are stuck in bores. If after thorough inspection and cleaning, you can't find the cause, it may be time to get the manual, and go through it step by step. I'll check mine and see what it says, but I don't have the loader on mine.