Clutch Slave Help!

[KDMatt]

I'm getting my car ready for summer (driving season is upon us) and naturally, this year, I've noticed that my clutch pedal is a bit too 'loose' ... and the engagement is pretty near the floor, so I bit the bullet and decided to replace the clutch slave cylinder.

The fluid that came out of the line was thick and black (good thing I'm doing this!) ... however now I've got a new problem.

My new slave is on, but my engagement point seems to be past the top of the pedal ...

I'm sure this sounds confusing, so here's what i mean...

You know how with most cars if you suddenly dump/let out the clutch without feeding the car any gas you'll kill it? Not anymore with my car.

... and in case you were wondering, I have adjusted the pedal travel too, it now travels upward all the way and still the same thing happens...

oh, and in case you were also wondering, I swapped out the new rod and reused the old one again -- no change.

It's a BrakeBest brand slave and it looks identical to the original.

Hrm... part of me is almost tempted to grind down the rod or something.

In any case, thoughts?

[Zs-ondabrain]

Loosen the lock nut on the rod connected to the pedal inside the car. Twist the rod into or toward the pedal, away from the clutch master.

This will allow a full engagment. Keep adjusting it till it's good for you. Then tighten the lock nut again.

Also make sure you bleed the clutch master as you probably have an air pocket in there. Just did this on the green bean and all is better now.

[KDMatt]

Loosen the lock nut on the rod connected to the pedal inside the car. Twist the rod into or toward the pedal, away from the clutch master.

This will allow a full engagment. Keep adjusting it till it's good for you. Then tighten the lock nut again.

Also make sure you bleed the clutch master as you probably have an air pocket in there. Just did this on the green bean and all is better now.

I appreciate the response.

I just made this adjustment. The locknut/rod were already adjusted all the way toward the pedal, so conversely I adjusted it all the way toward the master.

This has not had any effect on my problem. In fact, all it's done is shorten the amount of pedal travel I can feel.

Any more ideas?

.... I'm starting to think the slave I got is iffy (maybe I could/should use the seal from the new one and just fix the old slave?)...

Edited May 15, 2010 by KDMatt

[Zs-ondabrain]

ya, I realized how dumb my post was after I reread yours. DUH :stupid:

Brain fart. :classic: So it's holding pressure and letting the clutch engage? Weird. I'd have to say "Iffy" master. Ususally the problem is just the oposite. Won't engage.

Nothing Jambing the rod? Maybe using a spacer between the firewall and the clutch master would give you a little more rod travel? Kinda like shaving the od, but without damaging the rod, in case you swap it for another unit.

It's late and my Family BBQ ran longer than expected, Brain dead and going to bed.

Dave

[KDMatt]

No worries Dave, I know how that goes. As it stands I'm not driving the Z right now (sadly... hopefully next week?) so I'm not in a HUGE rush ... but I am trying to get lots of stuff done on it this weekend.

I don't think the issue is the master because it was working fine (in fact, oppositely) before I swapped slaves. Before the swap I just barely had to lift the pedal off the floor and the clutch was hard on ... Now even if I let it up all the way, it's still only 3/4 engaged.

Incidentally, what I forgot to mention is that installing the replacement slave was a bit difficult because the rod didn't seem to want to retract as far inside of the slave cylinder housing as the original did. I'm beginning to think this is my problem.

I'm gonna pull off the new slave tomorrow (as I'm also kind of brain dead), and pull it apart, and see if maybe the cup or spring is a bit different on it... I'm thinking I might "frankenstein" the two slaves together to make one good one that works correctly.

The main issue with the old slave (now that I've taken it apart) is that the seal on the cup is bad, so fluid was slipping past it and going into the main boot.

[IdahoKidd]

You're not overlooking the obvious, you did bleed the line and the cylinder after installation didn't you? When you step on the pedal, how far down does it go before you feel the clutch begin to engage? I replaced the slave on my 77 recently, and did have to adjust the linkage under the dash a little, but there was more than enough adjustment to move the pedal around almost the full length of the throw.

It sounds like the car runs and you can actually tell when the clutch is engaged and disengaged? If so, I wouldn't fool with spacers or shims or different rods, although I might check to see if rod isn't cocked a bit or not seated correctly in the cup or in the throw out arm. It could be a bad slave, but I'm guessing probably not. Installation issue or a bad clutch (pressure plate). Tough to know without previous history.

Do post the outcome for us though. It helps the next guy and it gives the rest of us an "oh, yeah" revelation moment.

[Zs-ondabrain]

I think he's getting instant pedal as it's only doing a 3/4 engage, which means no dead pedal space.

But being brain-dead last night I thought he replaced the Master, not the slave. If the slave had to be forced into place to instal it, then YES, the rod needs to be shaved or something, to allow full release on the fork.

I really shouldn't respond to posts on 1 brain cell.

Dave

[KDMatt]

Ok folks, so here's what happened.

I took apart my new slave (after, again, uninstalling it) ... and it turns out the cup/seal assembly on the new one was longer than the one in the original. It looked like the manufacturer had attempted to compensate for this by machining the cup deeper, but, obviously, it wasn't deep enough.

I was able to correct this (through tedious and painful trial and error) by taking a drill, and quite literally drilling out the cup.

I ended up reusing the old rod again (since it had a slightly more uniform shape and design) and voila! All is well in the kingdom. The cup is drilled down an appropriate amount so that now I get good engagement, and, if I dump the clutch at idle, it kills the car (mixed blessing?), as it is supposed to. Huzzah.

Moral of the story: Can you buy a brand new slave cylinder for $15 from O'Reilly's? Yes... but for God's sake, don't!

... now I just need to bleed the damn brakes...

It never ends.

[IdahoKidd]

Hey, thanks for the reply and congrats for the solution. I bought mne at O'Rielly's and it went right on. Had to adjust the pedal throw but that was largely due to the lock nut being loose.

[KDMatt]

Hey, thanks for the reply and congrats for the solution. I bought mne at O'Rielly's and it went right on. Had to adjust the pedal throw but that was largely due to the lock nut being loose.

Out of curiosity, do you remember which brand they sold you?

[IdahoKidd]

I don't. It was $13 bucks, came with the push rod and rubber hose. Plain white box as I recall. I probably have the reciept on my desk, if I could only find it.

[KDMatt]

I hate reviving an old thread (especially one of mine), but as I was topping off my tranny fluid last night, I suddenly remembered something ...

I have a five-speed swapped from a later year Z. :stupid:

I can only imagine this is why my clutch slave was so much different.