Slave Cylinder Failure Confirmation/Advice TIA
 

It's been two years since I put the motor in my car...We didn't align the slave rod correctly on the first try, and one of my "helpers" thought if he just pushed the pedal harder it'd pop into place. Needless to say, after he left, I had to fish the rod out of the bell housing and remove the slave cylinder. I dissassembled it, inspected all the components (piston, coned o-ring, and spring) Everything looked okay, so I put it back together and re-installed.

TODAY (13k miles later), I'm backing the car out of the garage (for a much needed FD cruise) and as I'm depressing the clutch to coast a little..."SNAP"...WTF?! car stalls...pedal is on the floor. Hmmm...okay, that's weird.

I jack the car up, remove the starter, and start unbolting the slave adaptor plate...ATE Super Blue starts seeping out. Okay, I think this is good...at least the fork didn't snap or anything. I release the rear nipple, and try to push the rod back in...won't budge :scratch:

I remove the assembled and dissassemble...all the pieces still look good, I put it back together and piston can move again...although not the smoothest action.

My question is...what could have happened??? I use an ACT extreme pressure plate (way to extreme for the street...if anyone was wondering, does feel like I'm in a race car everytime I drive though, haha). Last time I drove, no signs of failure. First 5' of my drive today BAM FAILURE!

Next Question is...what are my options? Rebuild kit, New unit, or (I've read) FEED replacement? Anyone know where to buy a FEED unit? and the advantages? Rebuild kit worth it? Few more bucks and get a new unit?

If you read this far, please leave opinion.

Are you sure the fork didn't break? I've seen several crack toward the ends that fits into the t/o bearing and it's hard to diagnose until it's removed because it's usually only one of the two fingers that break. This will also give you a hard clutch pedal travel.

well, the hard clutch travel only happened once...I didn't reinstall after the "second" rebuild, I just moved the rod in and out of the cylinder and that's where the rough action statement came from.

If the fork broke, would it cause my slave to leak? I guess if the rod came out...no?

the reason most people think the rebuild kits suk is that they never hone the cylinder. how does the bore look/feel any gouges?? i put the rebuild kit in my slave/master with no probs. i think it is like 10 bucks

Is a machine shop the best place to do the hone job? Or can I take it to a dealer?

cylinder is smooth as glass on the inside...but the piston has color on it???

http://i7.photobucket.com/albums/y28...p/DSC07883.jpg

http://i7.photobucket.com/albums/y28...p/DSC07882.jpg

Damn...the more I think about why this happened, I start to think the fork broke and "allowed" the rod to come all the way out :(

piston color does not matter as the rubber seal is what rides on the bore. yea if the fork broke it would push out. it should have a good amount of drag to it when you move it by the way. hyd tend to go soft when the seal fails as the pressure bleeds past the rubber.

time to get a good mirror and look at the fork....

^thanks...I think it's time for that JDM tranny (nice 5th). I was having high RPM 1st to 2nd "fast" shift problems/grinds...and now that I think about it more, I believe I had some vibration as I'd touch the pedal. Kept telling myself it was due to the extreme PP. I have a feeling this will be a long project...as I might pull the motor to get to the tranny, and make some "changes".

Bingo.

I replaced my clutch fork with the new 'upgraded' model when I put the ACT clutch in. Hopefully it holds... I'm not running the extreme pressure plate though.

what is this upgraded model you speak of?

The part number for the stock clutch fork changed a few years back, and supposedly they are stronger now. Looked the same to me though...

IMHO, it's far better to get hydraulics new. I've beaten the horse of hydraulic component rebuilds in the past, and have had to re-do my work then finally just buy the part new. The slave and master are pretty reasonably priced, especially if you can find a local parts store that sources the new Tokico parts (Tokico made the hydraulics for Mazda, BTW).

With a heavy pressure plate, you increase the hydraulic load the entire system sees. It will typically wear the components out faster, and if you have old hydraulics, you'll likely have a failure pretty soon.

I've also seen components fail all at the same time. If one goes, do the lot. If you put in a nice, tight slave, you'll increase the load the old, worn master sees, so it fails sooner. Then, you increase the load on the rubber clutch hose....

Dale

actually the rubber hose was the first to go...replace with SS, the rest is history.

Not Slave, Not Fork...to Bearing
 

Figured I'd bring this back to see if I can get some answers...well, the slave looked fine...the fork wasn't broken...it was the Throw Out Bearing. I haven't taken a picture of it yet...but it royally failed. Ball Bearings started to drop out before I got the PP off. Basically, the bearing that connects to the wedge collar stayed with the PP, and everything else on the fork.

Can anyone explain why/how this would/could have happen?

TIA

I would like to see some pics.

what? is my misery your enjoyment ;)

I'll see about snapping some pics tonight...should have done it last night; stupid.

Any ideas PHIL?

If your slave was not fully disengaging then your throw out bearing might have been under constant pressure. You said at the begging of this thread that you had some problems with the slave install. I think 13K of constant pressure on the bearing could have this repercussion? Also when you installed the throw out bearing did you put it in parts washer or brake cleaner etc.? Because I've seen them fail from this before too.
-J-

^that's a negative. (part/washer etc)

I did have an issue with the initial install, but rebuilt the slave before reinstalling...I'm not sure I follow how the slave couldn't fully disengage?

I did hear some gumbling with the clutch pedal pressed in. And some gear grindage at high rpm fast shifting between 1-2 and 4-5 (shifted fine normal street driving). 2-3 and 3-4 were always butter. Minus the unhappy TO bearing gumbling.

am I painting a better picture now?

meaning the piston was getting "hung up" in the cylinder. ie still holding more than normal pressure on the bearing causing it to heat up dry out and break.
-J-

how was the pedal free play before it failed??

You know me.. I love to see others suffer! LOL!

I'm not 100% and just wanted to see some pic;)
Only thing I could think of is that if your ball bearings came out of the throw out bearing, it could be your high pressure plate which needed more force, which in turn created more heat, causing pre-mature ball bearing wear and eventual failure. But thats my guess. I say inspect the ball bearings and see if you see anything unusual..

no free play in the pedal...pretty stiff from the top to the floor.

the reason the BB's came out is because the "inner" bearing (we'll call it) came out of the assembly.

I'm sure the pics will do the failure justice, ha!!

no free play is not good. you should have at least a 1/2 inch

^thats what i was trying to say...... its not only at the pedal but its probably holding pressure on the bearing.
-J-