question Z5245 - Clutch will not disengage and now pedal won't go down

[maple fox farm]

Clutch not working on 1992, 5245

I have read many of the posts on stuck clutches and they were very helpful. However, I don't think i saw one where the clutch pedal (eventually) got stuck in the up position. I'm going out to try some of the things i read about but in the mean time i figured i would post incase a stuck clutch and a stuck clutch pedal were good diagnostic symptoms.

So, the tractor sat outside for a while, clutch would not disengage with pedal down. Got it out of gear, started it and drove up a hill with the pedal pressed in and it let go; great! Then, sat for a long time outside and again, the clutch would not disengage when I pushed the pedal down when trying to start it. Got it out of gear, fired right up, slammed it back into gear with loader bucket driven into the ground, wheels started turning with pedal pushed down but the wheels just started digging down and the clutch would not let lose. But wait, it gets better! I decided to brace the clutch pedal in the depressed position in the hopes that in a few days, it might just let go in the middle of the night. So, a week or two later I went to check if it worked, it did not, and now, after letting the clutch pedal up, it will not go back down. I can stand on the pedal, and it won’t move a millimeter (not going to start jumping on it, I have enough problems already).

There’s plenty of hydraulic fluid, replaced the slave several years back, master is not leaking. It’s not technically difficult to split these things but it is a pain and I’d rather not do it until I know there are no other choices.

Any help and ideas would be most appreciated!

 

[Joachim]

Hello and welcome Trevor!

I can see these possible causes of the error straight away:
- wrong brake fluid (DOT4) used instead of DOT 3 - DOT 4 can cause the brake hoses/clutch hoses to swell inside and then fluid only goes to the slave when the pedal is pressed, but not back again on its own
- rust and/or wear on the driver (toothing) of the drive clutch disc and/or the transmission input shaft of the drive
- rust on the master cylinder or the slave cylinder

When was the brake fluid last replaced?
- this must be done every 2-3 years, especially if it is left outside a lot and/or in high humidity very important

What brake fluid is used?
- I strongly recommend using only DOT3 on these machines!

Was "brake cylinder paste" (ATE) used when assembling the cylinders?
- this is urgently needed to prevent rust on the cylinders

And it would be nice if you could briefly introduce yourself and especially your Zetor in words and especially pictures.

 

[Renze]

What brake fluid is used?
- I strongly recommend using only DOT3 on these machines!

Why is that ?

I have always used DOT 4 (i dont even know where to get DOT 3 locally) and never had problems. DOT 4 is just a higher spec version of DOT 3 with a slightly higher boil point, but both are Glycol based.

Now DOT 5 is Silicon based, which makes it a totally different fluid. It is dyed to make clear that it cannot be mixed with DOT 3 or DOT 4 Glycol based brake fluids.

 

[maple fox farm]

Hello and welcome Trevor!

I can see these possible causes of the error straight away:
- wrong brake fluid (DOT4) used instead of DOT 3 - DOT 4 can cause the brake hoses/clutch hoses to swell inside and then fluid only goes to the slave when the pedal is pressed, but not back again on its own
- rust and/or wear on the driver (toothing) of the drive clutch disc and/or the transmission input shaft of the drive
- rust on the master cylinder or the slave cylinder

When was the brake fluid last replaced?
- this must be done every 2-3 years, especially if it is left outside a lot and/or in high humidity very important

What brake fluid is used?
- I strongly recommend using only DOT3 on these machines!

Was "brake cylinder paste" (ATE) used when assembling the cylinders?
- this is urgently needed to prevent rust on the cylinders

And it would be nice if you could briefly introduce yourself and especially your Zetor in words and especially pictures.

Thanks for the quick reply!
99% sure it’s been dot3 for as long as I’ve owned it, about 13 years. I’ll find some partly full bottles in the shop to double check.
Fluid is probably 3-5 years old. Would that prevent the plates from separating or stop the pedal from going down?
When you say swell, are you saying that there are rubber hoses in the assembly line, I was pretty sure all my lines were metal. Are you saying the metal one’s expand?
I replaced the slave to the clutch years ago, but it came fully assembled. Are you saying to put paste on the piston rod?
If it is rust on the clutch driver teeth and or rust on the input shaft, does that mean I have to split the tractor?
Thanks for all your help !

 

[Joachim]

When you say swell, are you saying that there are rubber hoses in the assembly line, I was pretty sure all my lines were metal. Are you saying the metal one’s expand?

betwen master and slave cylinder you have rubber hoses (NBR). NBR can swell inside if it comes in contact with DOT4. Same thing the rubbers inner the cylindres.
DOT 3 will be fine - no problem for NBR rubber.

I replaced the slave to the clutch years ago, but it came fully assembled.

Yes and no. Yes, the cylinders come fully assembled. But there is only a little preservative oil under the dust protection sleeve. This does not work forever. That is why we use brake cylinder paste from ATE on all components that can come into contact with brake fluid and are made of bare metal.

ATE brake cylinder paste 180g

ATE brake cylinder paste 180g tube for lubricate and preserve cylinders in caliper and master cylinder

www.xn--batzng-eua.de

The paste (here green colored) also protects the rubber dust protection sleeve very well against ozone and thus against cracking.
All of this together prevents the penetration of moisture or water and thus rust.



If your clutch pedal is acting up again, do the following test:
Open the bleeder nipple on the slave cylinder - if brake fluid is coming out under pressure, then the hose to the master cylinder is blocked and/or the master cylinder is not correctly adjusted.
Incorrect adjustment means that the small inlet and return hole in the master cylinder is not clear, the brake fluid cannot flow back on its own.
It's a simple test.

If that doesn't work, you'll probably have to separate it to get to the clutch plates and thrust bearings.

 

[maple fox farm]

betwen master and slave cylinder you have rubber hoses (NBR). NBR can swell inside if it comes in contact with DOT4. Same thing the rubbers inner the cylindres.
DOT 3 will be fine - no problem for NBR rubber.


Yes and no. Yes, the cylinders come fully assembled. But there is only a little preservative oil under the dust protection sleeve. This does not work forever. That is why we use brake cylinder paste from ATE on all components that can come into contact with brake fluid and are made of bare metal.
View attachment 1207 View attachment 1208

ATE brake cylinder paste 180g

ATE brake cylinder paste 180g tube for lubricate and preserve cylinders in caliper and master cylinder

www.xn--batzng-eua.de

The paste (here green colored) also protects the rubber dust protection sleeve very well against ozone and thus against cracking.
All of this together prevents the penetration of moisture or water and thus rust.



If your clutch pedal is acting up again, do the following test:
Open the bleeder nipple on the slave cylinder - if brake fluid is coming out under pressure, then the hose to the master cylinder is blocked and/or the master cylinder is not correctly adjusted.
Incorrect adjustment means that the small inlet and return hole in the master cylinder is not clear, the brake fluid cannot flow back on its own.
It's a simple test.

If that doesn't work, you'll probably have to separate it to get to the clutch plates and thrust bearings.

Ok, thanks, I’ll try that

 

[Renze]

How this sounds like to me: The clutch is depressed, thereby the slave cylinder went out. Either a seized slave cylinder or a rusted throwout bearing yoke shaft is creating more friction than the clutch springs can overcome.

I would check if you can push back the slave cylinder. Then try to pull back the actuation shaft.

If it was a matter of clutch plates rusted to the flywheel it wouldnt build up the clutch till you cant depress the pedal.

 

[maple fox farm]

I really appreciate this answer. It makes a lot of sense. the one thing I don’t understand is the last sentence you wrote. Specifically, the part where you said, “it wouldn’t build up the clutch till you can’t depress the pedal.” Did you mean “bind” instead of “build” or am i not understanding the point?
Thank you very much for your help and time.

 

[Renze]

the one thing I don’t understand is the last sentence you wrote. Specifically, the part where you said, “it wouldn’t build up the clutch till you can’t depress the pedal.”

I said build up. The master cylinder pushes fluid into the slave, and when you take your foot off the pedal, the fluid from the slave comes back. If it doesnt, it draws new fluid from the reservoir. Then you cant push the clutch pedal down another time, because the slave is already extended to its limit.

So yes, because the throwout bearing yoke shaft or the slave cylinder piston is binding, the fluid column between slave and master cylinder builds up, so you have a fully depressed clutch with a pedal that is back up like nothing is wrong.

Release the slave bleeder if you try to tap back that clutch bearing lever. If it comes back as soon as the fluid oozes out the bleeder, you have a stuck master cylinder piston or a rubber brake line failure, it happens that the inner mantlet comes loose from the woven plies, becoming a one way valve. (Oh, Joachim already said that) I had that on a lawn mower gas hose.

Plan of attack:

Crawl under the tractor and open the clutch bellhousing inspection hatch. Remember how it looks.
then bleed the clutch slave. Does the oil squirt out and you see the throwout bearing come back ? Then a deteriorated rubber brake hose has become a nonreturn valve, OR your master piston is seized (though ive never seen that in real life)

You can test it by depressing the clutch with an open bleeder screw, to see if there is a fault between pedal and slave. Rule that out first.

 

[maple fox farm]

Thanks a bunch, that makes total sense. I’ll investigate tomorrow.

 

[land_locked_sailor]

I had the exact same problem. Turns out, I have to grease the clutch release every month or so. Under the access panel on the clutch side is a tiny port with a red cap. Pump a few squirts of grease down there and then jump on the clutch pedal until it breaks free.

 

[Joachim]

@land_locked_sailor
Adam,
... but only a few drops of oil should be added there (I'm serious, see the tractor manual ) and these only lubricate the clutch thrust bearings. If you overdo it here and the tractor is in an unfavorable position, the oil can run to the clutch discs and then ruin the linings there.

So if you add a few drops of oil there once or twice a year, that's completely sufficient.
Otherwise, just lubricate the clutch shaft on both sides of the clutch bell a little (!!) twice a year, ideally with an EP grease and only a little grease. If you lubricate too much here, a huge amount of grease will collect in the clutch bell... not good.

 

[land_locked_sailor]

That's actually great to know. I didn't use straight oil, but some heavy duty grease. My grease gun has a tip that allows me to squirt down the hole.
Thanks!

 

[Joachim]

I dont be sure grease is working there...
Better just use gearbox oil (SAe 80W-90 API GL4), thats what Zetor prefer for this.

 

[ianyoung77]

My operator's manual says every 100 engine hours
Clutch releasing sleeve lubricate / 1 SAE 30 SAE 10 W/30

Is this what we are talking about? Squirt some through the tube under the red cap on the LH side inspection panel which the parts manual calls "Cover with tube"?

 

[Joachim]

Yes - but one squirt will be there more thän enough every 100 hours.