hydraulic help please at witts end!

LOOMER · Jan 15, 2009

i have a 73 1530 jd. I am getting shutter and then quits working all togather. the fel goes first, then the 3pt. then the steering, and finally the trany will stop. it is completly random. will do this cold or warm.

What i've done: fluid flush with new filter and cleaned all screens.
rebuilt hydraulic pump

since i've done this i've clocked about 16hrs with no issues. today ran it for about 8 hours then it crapped out on me again. exact same issues. When the tranny finally stopped today i let it sit for about 10minutes and it was able to make it to the trailer. it seems if i let it sit shortly it will function for a very short time then act up again. i also noticed today air bubbles coming out of the hydraulic fluid dipstick. i don't know if this is normal or not.

It has been in the barn since the fresh fluid water isn't the issue. i am stumped. The hydraulic rebuild was just o-rings and i don't see any obvious issues.

thanks for your help!

Gary Fowler · Jan 16, 2009

That sounds a lot like my Yanmar 4220 hydraulic issue that I am having. I have flushed and changed the oil 3 times now and it still barely operates. The hydraulic screen was stopped completely up with gray greenish slimy material and some black goo. This caused first a jerky FEL movement and 3 ph took 5 minutes to raise. The Power steering was hard to move and finally it would not move. It has a shuttle shift with a hydraulic clutch so when it get no oil, it stops. Anyway, while cleaning the screen, I pulled out about 1/2 cup of grey sludge with my fingers. I am sure there is more in the hydraulic reservoir. I am going to flush it several times with diesel fuel, to try and dissolve the sludge and then flush it out, then flush out the diesel fuel with some AW 32 that I have left over then use JD303 to refill. Then I will install a new paper hydraulic filter and hope it works.I think the greymarket dealer put the wrong oil in to start. If that doesn't fix the problem, the last option is replace the hydraulic pump with a new one.

kennyd · Jan 16, 2009

I think seeing the air bubbles is the answer...If after the machine acts up the fluid is foamy looking, then I would suspect a leak on the SUCTION side of the system. This "foaming" condition causes the pump to cavitate.

LOOMER · Jan 16, 2009

Anyone have ideas on how to trouble shoot air leaks or where to look? I don't understand how it could run all day then crap out and the cause be an air leak. i have a new vented resivor cap and have tried running it without the cap.

woodlandfarms · Jan 16, 2009

Heat maybe? something warms up to the point of letting air in... Will be a real PITA to find if this is the case...

MJPetersen · Jan 21, 2009

It cold be that it sucks air when the screen or filter slightly plug which decreases the flow on the intake side of pump. Check every rubber hose connection specifically if there is a hose-over-tubing-with-a-clamp kind of connection.

Mike

slowzuki · Jan 21, 2009

try ytmag, lot more people familiar with oldies there. Big JD's back then had closed center hydraulics, not sure about the little ones.

LOOMER · Jan 25, 2009

Alright, i have another discovery. I keep blowing out the front input seat on the pump. I took and had the pump rebuilt and the oil cooler pressure tested. Put everything back togather and noticed the seal is blown again and the oil cooler and resevoir tank is empty. I then filled the cooler and tank all ran fine besides the leak. Once the resivoir and cooler emptied out quit working again.

So what would cause the seal to keep blowing and why is the tank and cooler not being filled w/ oil. ahhhhh!

RWolf · Jan 30, 2009

As far as the seal I'd suspect a blockage/restriction on the output side of the pump and the relief is set to high or not working all together. As far as bubbles I agree that you have an air leak on the suction side. Very tiny but air will pull easier than fluid. Replace one or all hoses/fittings from the tank to the pump should cure that.