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| Hey all, we have a JD 2950 cab tractor. Went to drive it and had half a clutch, won't disengage the engine. Seeing weeping around the master cylinder we suspected possible air-fluid exchange so we replaced the seals. We bled a lot of new fluid, the old stuff looked vile, through the bleed screw on the slave cylinder using a clean oil-can. We attach a clear hose full of brake fluid to the bleeder and then pump with the can once the bleed is open. Its supposed to force air up and out.
We tested the tractor and saw improvement, could actually drive it, but still had rough shifting on 1&2. Bled some more and got a couple more air bubbles out. Tested it again and now have a Very weak clutch. Can't do anything, just grinds if you try.
Just found out that this tractor has a HI-LO lockout, located under the cab, and so we've started bleeding from there instead because its past the slave and has a bleed screw.
Any tips on how to better bleed out infiltrated air?
NEXT DAY...
I tried something else I had read. We used a pry-bar to pry back on the slave cylinder's piston, then applied pressure from the clutch as we released pressure on the slave-cylinder piston. Once the clutch is to the floor and the slave rod is back, we release the clutch slowly.
This produced Alot of bubbles and a very weak clutch. A little more back-bleeding from the slave bleed made more bubbles and stiffened up the clutch. We've done this 6 times now with the same results, perhaps alittle less bubbles now. We've gotta eliminate the bubbles, so we'll keep doing this but we'll back-bleed from the bleed under the cab, the HI-LO lockout, instead. Any other ideas, anyone?
HOURS LATER...
From the amount of air that we were getting constantly from that method of slave-cylinder prying we decided that we must be leaking air into the slave cylinder when we release the clutch. I also heard something of a suction sound at the slave while the clutch is released. Is it possible that those are one-way seals for the piston in the slave that would allow air to force past? Is there any way that we can avoid creating that suction while releasing the clutch, like squirting fluid into a bleed screw while releasing the clutch?
I still don't think that the slave seals are shot because the slave was dry and clean when we started this game. The rubber boot on the piston was shot, but it was clean, too. Any ideas or alternative methods would be appreciated!
NEXT MORNING...
Got some papers from JD describing bleed process. Not any different than what we have been doing. People say that this is difficult, but should it take multiple hours?? With no real results?
Thanks in advance,
Edited by jdprobman 9/4/2013 12:05
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SE Nebraska, Near Misery and Cans Ass! | This is testing my memory and that's not good but I seem to remember a tech hooking a portapower to the bleeds and back bleeding one. Seem to remember replacing every part in it to get it to work. Info Worth what it cost you. |
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Kingston,Mi | Did not see any mention in your narrative about starting bleed process with a full reservoir of brake fluid. When I have rebuilt or replace the slave or master cylinder, it has never been more than a dozen or so strokes of the clutch pedal, pedal down then open the bleed screw, wait for it to quit running , tighten bleed screw and repeat. |
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| Thanks for the replies. I thought to bleed that way at first as well, but according to my research and the JD guys you have to bleed backwards to what you generally do. Force fluid from the bottom to the top. And when I started bleeding I had an empty reservoir and master cylinder because I had drained those when replacing the seals. The stuff in there was bad.
I am beginning to wonder if this is an air issue anymore...what else could it be?
Edited by jdprobman 9/4/2013 14:25
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northwest tennessee | How many hours on clutch? It sounds like the clutch to me. |
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South Central Kansas | Replaced master and slave cylinder on mine replaced seals in lockout and bled it backwards and it worked. That tractor spent more time in my shop than outside. Worked on transmission twice and clutch once deere does have an update for the clutch if your tractor doesn't have it I would put it in. I traded min for a 4440 and I am much happier. |
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Upstate Ny | ive bled my a couple times, once when we put a new slave cylinder, and once when the hose blew. id change the slave. they bleed really easy. |
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northwest tennessee | Is there an update for the 2955 too or does it have it already? |
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| When we started bleeding we did it the conventional way, how you bleed cars etc. And we got air that way, but after a google search found out to do it backwards. What would be the symptoms if it wasn't an air issue? Anything would be appreciated, thanks! |
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| Seals for the slave cylinder should be in tomorrow. Hopefully I will be able to get the thing working again after they are changed. I've been going with what is suggested here: http://forums.yesterdaystractors.com/viewtopic.php?t=1058206 |
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| Success!! Here's what I ended up doing.
I changed the hose that leads from the reservoir to the master cylinder after finding 4 big cracks in it.
I just kept bleeding the system the conventional way you bleed brakes. The interesting thing was that I often had to play with how I released the clutch to get the fluid from the reservoir to flow down.
After a couple hours I was about to give up, as the flowing of the fluid was getting trickier to keep up and I still seemed to be able to occasionally squeeze little bits of air out, but I decided to try the clutch before I tried the other method.
It was stiffer than it has been since we started this game, and so I started it up. All the gears shift as smooth as hot butter, even better than when we got the thing! I took it for a little spin and had absolutely no trouble shifting to-and-from any gear.
It's fixed!! Thanks everyone for posting, and I appreciate all the advice that you guys have given me!! Especially JD Seller. Your tips were what did it!
Here's where the main discussion has taken place: http://forums.yesterdaystractors.com/viewtopic.php?t=1058206 |
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JD 2950 cab tractor clutch issue
