So here's the deal. I've had my 2009 LNF for some time and I love it. Well, I came across one on craigslist for really cheap due to the slave cylinder going out. We bought it, pulled the tranny, and threw in a new slave that quickly blew the seal. After trying three slaves (different brands), it's obvious that that's not the problem. It would seem that the pressure plate on the clutch is defective upon inspection. (It's a SPEC stage 2 that has seen better days). Our next move is to go ahead and replace the clutch. It'll be a while before we plan on making big power so we were just going to throw in a stock clutch replacement for now, only, the only ones I can find are for 2005-2007 LSJ balts instead of 2008-2010 LNF's. If I use the same flywheel that's already in the car, can one of the LSJ clutches work? After some research, it seems the only difference between the two clutches is the pin patterns on the flywheel. Is this true? If so, can I just get a kit with another flywheel and call it a day? Any help is apprectiated.

 

The LSJ and LNF both use the same flywheel that has 8 bolt holes. I would recommend to use a new flywheel and new flywheel bolts(because they're torque to yield) when installing a new clutch. This allows for the clutch to have a new mating surface to break into. Is the thin metal spacer behind the TOB still there?

 

Lnf flywheels are on nation wide back order.

 

$200 to me and I'll send you a new LNF flywheel third party.

 

So just a little update. Replaced the clutch (flywheel is in great shape so we left it alone) and the problem persists. The slaves are blowing out the end so my thought is that maybe it's being over extended. Is there a way to adjust the master cylinder to reduce the amount of pressure being delivered to the slave? Or is the master defective maybe? It seems that would be the problem since everything else in the hydraulic portion of the clutch assembly is brand new. Any ideas? Or even better, has anyone else ever dealt with a problem like this?

 

It shouldn't overextend if there's a correct pressure plate in there. Are you sure the TOB is sitting flat on the case of the trans? I've seen them blow out because of issues like that, but not really any other reason to cause repeat failures like that.

Is there an adjustable rod on the master cyl? ZZP sells one and it's a band-aid fix for the poorly designed aftermarket clutches, if it's overextended you may need to shorten it back to stockish length.

 

Yes, we're sure it's sitting flush. That was the first thought we had when we blew out the first one. So the ZZP part might fix the problem?

 

I meant see if there's already one in the car.

By default, the floor of the car is the stopping point for the clutch pedal. So it's not fantastic but it's almost impossible to overtravel a stock master and do damage. IF the pedal is going through the carpet or something, maybe. But still, a good condition slave should be able to handle a hair more travel without popping. IF the adjustable rod is already in the car and extended out too far, it might be a lot more travel than stock.

 

I'll double check but I'm almost positive that it's the stock rod

 

I had a spec on a f23 doing the same thing, threw it away and bought an exedy.

 

We did remove the spec. Put a brand new stock clutch in and still blew out a slave. It makes no sense to me.

 

How are you bleeding it? Are you filling it up before you start the bleeding process.

 

Yes, we fill up the reservoir first. Then we do the manual bleeding method involving one person operating the clutch and one on the bleeder valve. I used the same method on my Balt and it worked well.

 

I think 64 Nova was asking if you did a "bench bleed" first where you fill the slave/TOB before installing. IIRC, John Powell posted a method to do this but it seems like that's usually not recommended. I'd have to go look at the CrateEngineDepot paper to verify and I don't want to right now.

How hard is the person operating the clutch pushing the pedal? If they're pushing fast and there's still air in the TOB then it could blow it out. The best way is to apply vacuum to the reservoir and slowy move the pedal in and out. CED has the definition of slowly, again IIRC. You shouldn't need to operate the bleeder. Besides, it looks to me that the bleeder wouldn't really help to get air out of the TOB.

 

I just picked up a vacuum bleeder today. We're going to give it a shot tomorrow when the new slave arrives. I will update after

 

I'm having that same issue I'm on slave #3. What did you figure out? Any help would be great I'm stuck

 

Turned out to be the master cylinder over pressurizing the slave cylinder. Put a new master in with the new slave an the problem went away. Been good for 10,000 miles

 

Hm that's weird. I actually watched the slave over extend. So I'm thinking of putting a stop on the pedal just enough for it to die gage and shift.

 

This is why I always say to replace ALL hydraulic components when replacing a clutch.

Glad you figured it out man