Thread: Hydraulic Clutch Linkage Problem

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A couple days ago my son lost the clutch on his 95 Z-28. He said he noticed it not shifting right the last couple days. (T-56) (I assumed that was because the slave cylinder wasn't traveling far enough as it was going bad.) The clutch didn't slip & there were no tell tale noises of something going bad inside the bell housing. We had it towed home and yesterday Jeff put a new clutch master & slave cylinder in. There are no bleeder valves so we've been trying to bleed the system by bench bleeding, installing & pumping the pedal, etc. We've had it in and out of the car several times trying everything we can think of but still no werkie. Is this a normal problem bleeding with with new parts? Is there a trick to making this easier or do we just keep trying to bleed the air out until it works?
Is there a chance we have other issues? I didn't think so because what little I can see through the slave cylinder mounting hole everything seems to look & feel o.k. inside the bell housing. That and there were no signs of mechanical problems with the clutch itself before this happened.

Jeff has a tune-up date with the dyno next week & really wants to get this deal figured out soon.

Thanks in advance for any helpful info.


Both master & slave cylinders are the plastic units if that makes any difference at all.

Are you sure there is no bleeder on the slave? It might be obscured but I bet there has to be one somewhere. Otherwise, how could you get any trapped air out of the system?

I'd look closely again.

Don

Look for something like a set screw on the slave. There has to be a bleeder of some type
Who is the slave made by. Call them up and ask them how do they bleed their cylinders.

alot of the plastic units do not have bleeders.

you fill it at an angle, make sure the master is full, make sure the line is as full as you can get it. Hook everything up and slave installed.
You'll need two people for this one.....
one person under the hood with plenty of fluid, and you need to get under the vehicle.
Get enough clearance to get under the vehicle, and with some sort of pry bar push the slave to fully retracted (slowly as possible) this will force fluid out of the master, so expect it.
As you release make sure the person up top is keeping the master full.
Repeat this procedure 10-20 times or until air stops bubbling out of the master.

go for a drive and work out the rest of the air if any.
I've done this hundred of times on cars and trucks.
Drew

Thanks for the replies. Drew, yes we've been pumping the slave push rod by hand and getting a few bubbles through the reservoir. Still not working but maybe we just need to repeat the process a few more times to get all the air out.

hehe, push HARDER!

good luck, the whole job stinks.
Plus of the many fluids to get in your mouth, brake fluid is by far the worst.

A friend of mine hooked me up with this link. Looks like the best method so far.

http://home.comcast.net/~buschman_00...utchbleed.html

thats great except for two things....
first it implies that that slave has a bleeder (if it did we wouldn't have this problem).
and he needs to understand the difference between psi and inches of vac, it could be really confusing when the new guy actually adds 20psi to the hydraulic line :-)

Originally Posted by DeepRoots

thats great except for two things....
first it implies that that slave has a bleeder (if it did we wouldn't have this problem).
and he needs to understand the difference between psi and inches of vac, it could be really confusing when the new guy actually adds 20psi to the hydraulic line :-)

Yea that's true but I think his basic principle will work, I sure wish they would have just put a bleeder on the thing & been done with it.

you might try assy.the ubit on the car then break the lines.don't remove them any try to get the air out thay way.

The lines can't be cracked open. They are o-ring connections held in place with roll pins.
Nothing about this deal seems to be easy. Yesterday we set the assembly up on the bench with the slave cylinder low and the reservoir tied off high. Every hour or so I would compress the slave cylinder against the bench & lean on it while pumping it back out with the master cylinder. Repeat a few times & them let it set awhile, while I went back to work on my own car. I got a few bubbles every time I went through this routine. Jeff took over when he got off work. He said the last couple time he didn't see any bubbles, so he's going to reinstall it today & try again.

Do you think the lack of bleeder is because they are aftermarket parts? I can't imagine any setup not being made to service like that. I went on some Camaro sites and looked up bleeding slaves for you and they discuss it just the way we have always done it, through a bleeder valve.

Don

If the cylinders are metal they have bleeders, if they are plastic (like ours) they don't . If you buy a stock GM unit (we didn't) they come pre-bled and ready to install. (Jeff didn't know that until after he bought this set-up). I've been told it will self bleed once in the vehicle because the master is mounted on the firewall right above the slave, but it is a very very slow process. That's why it's hard to get it going. Once it starts working (somewhat like priming a pump) it will work fine. They say you can do a maintenance bleed by simply pumping the master cylinder a few times using short strokes & then a full stroke. That forces the air out of the master cylinder & up the reservoir tube.
The problem is this bleeding process only removes a few little bubbles at a time, which is why the first time bleed is such a pain.

This is what it looks like...

yeah, alot of the plastic slaves I've seen do not have bleeders.

a metal slave with bleeder is only around $30 for my applications, I don't know about yours... that is always an option.

Jeff says if we can't get this deal going by tomorrow he's just going to buy the pre-bled GM assembly & be done with it. I have a good feeling about this one though, it's a whole lot firmer on the bench now. Hopefully it will work when reinstalled. He plans to install it tomorrow, so we'll keep bench bleeding until then.