Zetor Clutch (Again)

[BBarbour]

Thanks to all who helped the last time I had problems with my Zetor 4341 clutch, but its at it again! I changed out the clutch master cylinder per the suggestion of the dealer, and what a chore getting it bled. That was just 2 months ago. Well, now the pedal goes to the floor and no clutch! I think it is the slave cylinder, and probably was all along. There is a rubber sleeve that slides over the end of the slave toward the clutch lever end and it seems to fill with fluid. Is this normal? Or do I have a leaky slave and that is why the clutch won't move? Anyone know or have had similar problems? The fluid reservoir is full and I can't believe that the master cylinder is kaput again. Thanks all BWB

 

[BobQ]

The slave should not leak! The boot you speak of is to keep out the dust. I think you have found your problem.

Keep us updated!

Bob

 

[mudcat]

Yep, It's the slave. /forums/images/graemlins/crazy.gif

 

[BBarbour]

You think it IS the slave or NOT the slave? The rubber boot stays on OK but I can't figure out why the fluid builds up inside of the boot nor why the clutch hydraulics keep failing. If it is dust inside the boot, then has it caused the slave to leak or have the seals or whatever in the slave worn out? I need to get it fixed by this weekend or I can't move 3x4x8 hay bales out to my cattle in the pasture /forums/images/graemlins/frown.gif. Thanks again for your input.
Bruce

 

[BobQ]

It is the slave that is bad. There is an o-ring behind the rubber boot that keeps the fliud in, so to speek. The rubber boot just protects that area of the shaft and seal. If fluid is collecting behind the boot, it is passing the o-ring seal.

Bob

 

[BBarbour]

Thanks Bob. Kind of thought that was what you were saying. The hydraulic piston on the 3-point hitch is leaking and they sent me a rebuild kit, so I hoped there was much the same for the slave, but I guess not. The dealer says that the older models were even worse with having to replace the slave and the master more frequently then it should be. Seems that the newer models have not provided much of an improvement to this problem. Funny, my neighbor has a Zetor 3540 and has never mentioned a problem with either part.

Hey, any idea why the manual says use DOT 3 fluid and the cap on the reservoir for both the clutch and brakes say "Warning! Use only DOT 4 fluid!" ? Thought that may be some of my problem but can't figure why the fluid type would affect the operation of the clutch.

Bruce

 

[BobQ]

Break fluid absorbes moisture at about 1 percent a year, the moisture then settles to the bottom (the slave is most likely the lowest point). The moisture then corrodes the parts. Dot 4 absorbes water at a slower rate then Dot 3. Definatly use dot 4 in place of dot 3. Dot 5 is more complicated, it is silicon based and may not get along with the system components.

If it is not to hard, bleed the system every couple of years to get new fluid in, and the moisture laiden old fluid out. The new fluid will be clear, the old dark.

Hope this helps.

Bob

 

[BBarbour]

Spoke with Peter (technician at Zetor) today. Said the newer slaves are an improvement over the ones use until 2003 so the o-ring does not leak (as much?). Also said the master cylinder was probably not the problem, but the reservoir needs to be kept full above the outlet to the clutch master cylinder, which in fact may be above the min. line on the reservoir, so he said if the level is not high enough then air sucks in and that is how the pedal fails. Asked him about DOT 3 or 4 and he said the warning on the cap is placed there by the master cylinder manufacturer but 3 is just fine and that 3 & 4 are compatable so either or both together works fine - but like you said, stay away from 5 unless you flush the entire system and flush with alcohol, although there are not enough studies in that indicate there is a non-compatability problem, don't take a chance.

Thanks for the tip about water absorption. Since the tractor is 2 years old, might as well see if I can drain it now. Never heard of this before. Is that why those guys at the oil change places are always trying to get you to buy the brake flush deal too?

Bruce

 

[BobQ]

I am glad it worked. Brake fluid loves to absorb moisture, buy a small container and keep it tightly kapped! Keep the master full and keep it tightly kapped! Definatly use the Dot 4, it is still glycol based but more stable.

Bob

 

[BigCrzyRdNeck]

i am looking a getting a new zetor but with a shuttle should i have any of these problems with it if i get one. it will be my first shuttle ive been old school till i started using a loader.