So i recently acquired a 2005 cobalt ss that the guy no longer wanted to mess with. Long story short, guy had a clutch put in about 6 months ago and shortly before i bought it he would have to pump the clutch to get any pressure to be able to move it, so after doing some inspection i found the slave cylinder to be leaking. When i pulled the trans it had what looked like a stage 2 or 3 clutch in it and a factory gm stamped slave, nothing seemed to be wrong with the friction disc or pressure plate so i figured i would install the new slave and be good. After everything was put together i drove it about 5 miles and the slave i just put in was dumping fluid. I checked the seal on the elbow pipe and made sure it all clicked together and sealed, checked the pipe from elbow to slave with a bore scope and saw nothing so that leaves the slave. Could the pressure plate be too stiff for the slave and be blowing out the seals? Will be pulling the tranny again in the near future but would like a little insight before i pull the trigger on a guess

 

The throw out bearings for the f35 suck ass. Youre not the first ive seen to have a brand new one fail.

 

Is this going to be a trial and error kind of deal or is there a better option than oem? Its not a daily and i have all the tools and equipment

 

I dont think theres anything better than oem. Idk if anyone has ever tried an f23 one but i know they dont explode. Ill let someone who actually has an f35 chime in.

 

I feel for you. Fortunately for me when I did my clutch the slave that came in my kit worked perfectly.

 

This a kinda bs statement dude. 99% of oem bearing failures are from incorrect installation. Ive fixed atleast 20 of these and have installed atleast 50-70 clutches in f35 cars. Every single f35 failure have all been from someone doing something wrong during installation and thats why places are no longer warrentying them unless professional mechanics install them.

Im not saying there hasent been bad ones out there because its the nature of manufacturing but a lot of time they get tweaked furing install or over extended because of a resurfaced flywheel etc etc

 

Any advice then? This is the first time dealing with a tob/slave intstall on my part so could be something i missed.

 

Agreed 100%.

Clutch / hydraulic manufacturers have a tough product. A person who isn't qualified installs them, they don't work right and the maker gets blamed.

I've installed dozens upon dozens of clutches in all makes / models and I have never once had one fail.

 

I can see your point and from being a mechanic for several years have seen many parts fail out of the box from alternators to blower motors to sensors and electronic throttle bodies. Manufacturers can have defects which is what im trying to figure out here as to whether i got ahold of a bad part or if the pressure plate has too much resistance for an oe slave. Majority of the clutches i have dealt with have been external so i havent had an opportunity to mess with these. I appreciate the input

 

Oh I agree 100% with a lot of out of box failures especially on "rebuilt" parts.

I have to say though, that with brand new parts I'm really struggling to recall an out of box failure that I have personally encountered.

It does happen though.

The TOB/slave though, there's not much to it. Very simple device that's oh so easy to mess up during installation.

 

Its really strange honestly. Using a bore scope i can see it engage and disengage fully and the pressure is all there but its dumpimg fluid. Got even worse after i drove it another 2 miles. Suppose ill bite the bullet and throw another one in there and keep my fingers crossed. Luckily its not too bad of a job to do. Anything i can keep an eye out for or any advice is greatly appreciated

 

Yeah that's a stumper, sounds like you got a dud for sure.

I just made sure the bellhousing surface was clean where the slave seats.

I put a dab of loctite on the 3 retaining bolts, made sure the clutch pipe wasn't cross threaded and it was seated fully.

Never ever try to apply pressure to this setup until it's bolted up to the engine.

 

Cool cool. Ill probably dig into it next weekend and hopefully come out on top. Would be nice to actually take it for spin rather than look at it lol. Thanks for the input all

 

Did u lube the seal before wrenching it down

 

Which one?

 

Input shaft seal. In the center of the TOB/Slave is the seal for your input shaft but I personally don't see how this could cause the brake fluid to leak out. Correct me if I am wrong.

 

Cant recall. I believe so but i may have over looked that. Suppose it could have attributed to it leaking though if it wasnt riding on a film of some sort

 

Because a lot of times not lubing the seal can cause it to not sit properly and the throw out bearing wont be perfectly centered and when you engage it it will cause the seals to blow internally and then it pisses fluid.

The throw out bearings in the f35 have to be perfectly centered. Also did you suck the trans in or did it slide in easily to the dowel pins and thrn u suck it up.

 

I made sure is was on the dowels before pulling it together. Only had bolts a few threads in to keep it lined up.

 

If a person is using the bolts to pull a trans in then you're doing it wrong.

If you're on the dowls and can put the bolt damned near all the way in by hand then you're doing good.

 

its possible you could of gotten a dud. i mean it is possible. but ive literally deamed that whole shitty oem throw out bearing thing a myth because it is. Most of them i have found are usually due to something done by the installer.

the one thing you want to make sure of is you DO NOT resurface a flywheel because the tolerance is to easily blown. Thats one of the most common i find. i find guys wrench the trans together and tweak the throw out bearing or the tweak it trying to line it up. it doesnt take much to **** that thing inside. also like i said if you didnt lube up the seal with some assembly lube it might now of seated properly and gotten tweaked.

 

Got a new one ordered today at a local dealership that should be in by the end of the week. Will definitely be taking my time this go around.

 

Update: pulled trans over the weekend and found the seal on the slave had blown out completely. Installed new one and have been driving around town since saturday with no issues. Well, issues related to the clutch engage/disengage. Hearing a slight whine in first but all other gears seem good. Suspecting bad fluid and hopefully not a bad bearing on that gear

 

Glad you got it on the road.

The general consensus I've picked up around here when I had many MU3 questions is that these transaxles are kind of noisy and that's just how they are.

If things drive good, your fluid checks out without any etch a sketch tint to it then I would just accept a little gear / bearing noise as a-ok and drive!