WRE

Hey all,

I hopped in my C5 after work tonight and started it up just like normal. I leave the car in first gear with the parking brake on when I park the car. It was in this same condition when I started the car, though with the clutch pedal fully depressed of course. Immediately after the car started I heard a pop/snap/hiss, then felt the car lurch forward. Luckily the parking brake was on because my reaction to shut the car down was not quick at all!

The clutch pedal returns fully, but clearly does not have as much pressure behind it when being depressed. I cannot shift into any gear if I start the car in neutral, and the car begins moving immediately if started in gear. There is fluid visible if I open the reservoir on the firewall.

I think this is either a master cylinder or slave cylinder failure, does that sound correct? Right now my car is at work, is there anything I can do to drive it home (hour or less temp fix) or is a tow home inevitable? I know if I had to I could drive it home without a clutch, but that is not something I want to do for fun. I have AAA and free tows, I just absolutely hate having to have a car towed.


Thanks for the advice

WRE

I guess I should add some information on my C5

it is a stock 2002 convertible with 105,000 miles. The previous owner replaced the clutch and hydraulics at around 50k miles because the clutch pedal would not return from the floor. From memory, I think that was in 2014 when the work was performed

WRE

So I have been doing some research. I think it is the slave cylinder that has gone out on me. If it were the master cylinder, then the pedal would stay stuck to the floorboard. In my case, the master cylinder is still developing line pressure, it just isn't pushing the clutch because the slave is leaking internally.

Does this sound logical?

coupeguy2001

Try to bleed the slave.
If the master is putting out, you would get a lot of fluid, and the pressure good or bad will be evident.

My opinion would be to just replace both, and press on

WRE

I don't think I can bleed the slave without removing most of the drivetrain, correct?
I was hoping there would be a temp fix that would allow me to drive the car home from work. Once the car is home I will be replacing the salve and master - possibly the clutch too

coupeguy2001

Don't think there is a temporary fix. Have it towed home.
There has to be connections on the master, and where the line goes to the slave? loosen that line, dont take it off all the way.
wrap that in a couple rags, and have someone press on the pedal.
You will feel the pressure in the rag, and the rag will have brake fluid on it.
Don't get any on your paint. it is the best paint remover there ever was.

Then refill the clutch master with fresh fluid. and try it again. If there isn't any pressure, change the clutch master.
There is still a provision under the car to bleed that line. You can always open it, and pump fluid through it till you get fresh fluid.
With having your pedal"pop", I would think that the master is no good.

ccporter

i would just have it towed and look into once you have the car home. not really worth the risk of getting into an accident or tearing something else up, i would check and make sure your clutch line didn't pop apart, that would be about the only thing you would be able to fix easy with out being able to get the car in the air, and even then it is a pain to put the connector back together if that is what is.

WRE

Well I had the car towed home tonight. It was actually no big deal at all getting the car on the tow truck. The driver had towed several corvettes before and knew exactly what to do.

The car is now up on jackstands and I've had a chance to poke around. The bellhousing is covered in fluid and clutch dust, everything else in the surrounding area is completely clean. I guess it's time to buy some part and turn some serious wrenches....

ccporter

It's not that bad to put a clutch in, just make sure you do a little research. And I would highly recommend check the angle before you separate the drive train

WRE

Yes, I have a lot of research to do! What angle do I check?

ccporter

huesmann

He means that you should maintain the same angle of the engine tilted back and the TT/transaxle so that they are the same when you pull the input spline out and when you put it back in. You can use jacks (bottle or floor) to keep the engine tilted at the same angle. Make a note of how high your jack at the transaxle is, and put it back that high when it's time to stick the input spline back into the clutch disc.

WRE

Well, I went to work this weekend and removed the entire drivetrain. The inspection cover on the bellhousing was covered in fluid and clutch material, as was the inside - as expected. The slave cylinder is completely dry, and looks brand new though. I drive my car in the rain, this fluid isn't just rain water is it? I would be a little bummed if I took the drivetrain out and it ended up being the master cylinder.

While I have the car apart, I figured I would look at the clutch too. A few spots are worn down to the bottom of the wear indicators. It sure looks like there is a lot of clutch material left though. Hoe many miles approximately are left on the clutch? It currently has 40k

neutron82

if doing it by yourself take the torque tube loose from the trans/diff and put that in first... it doesn't weigh much and is easy to maneuver without all the added weight of the trans/diff/suspension on the back of it... this way you don't have to worry about any angles and once you get that stabbed the trans shaft will go into the torque tube pretty easy and it's all downhill from there

ccporter

I wouldn't put a clutch back in that had more then a few thousand miles unless it was out because of non clutch related issues and was something more then stock style clutch. They aren't that expensive to risk having issues down the road. But that is just me.

huesmann

Agreed. If it's worn, replace it. I don't see how a failed master cylinder would drip any fluid into the bellhousing, though—the hose from the master connects to the slave outside the bellhousing. It's gotta be from the slave, unless the fluid isn't brake fluid.

WRE

My only thoughts on the fluid (if it isn't clutch fluid) is that it is either oil from the rear main seal or rainwater?

I wish I could see what color the fluid was, but I didn't do a good job maintaining the clutch fluid so it is pretty dark to begin with. Then add in all the clutch dust and you get a nice brown grainy liquid....

Bobtam

This is the safest way to do it.

ccporter

Just curious to see how your getting along with getting it going again.

WRE

So a few developments....

First off, I did a little more poking around and believe my original diagnosis was wrong. At this point, it really doesn't matter since I'm replacing everything clutch related, but I probably could have fixed the car much quicker had I done some more in depth diagnostics. What I noticed, is a stream of clear fluid dripping down the floorboard from under the steering column. So my master sprang a leak, and the slave cylinder has been good this whole time.

So what was all that fluid in the bellhousing? Well my oil gauge pegged to 130 psi about a year ago. I'm thinking that the sensor finally began to leak. This oil then dripped down the back of the engine, down the plastic covers on the front face of the clutch inspection cover and pooled in the inspection cover. Who knows though, I did find another thread about having a bad slave, they also described their slave as completely dry when inspected.

Since my LS1 clutch that was in the car only had 40k miles and was working fine when pulled, I decided I'd push the cost of a new clutch down the road and reinstall my old parts. Something went terribly awry though. When I torqued down the pressure plate (in 4 passes, following the manuals star pattern) somehow one of the mounting surfaces wedge itself against the alignment pin about 1/16" or so so off of the flywheel surface. Bringing the pressure plate bolts to full torque then actually bent that mounting flange of the pressure plate. I tried some shadetree mechanic techniques (hammer) to flatten that flange back out. I could not get the pressure plate to bolt up without having some sort of displacement in that flange. That small displacement made the clutch fingers misalign by a large amount. So I took the hint and ordered a new ls7 clutch kit along with some ARP bolts.

The good news is that the torque tube bushings look brand new! I also ordered a C6 tunnel plate from ebay. I painted it with some ceramic paint, and am going to try and use the stock tunnel plate, upside down, as a heat shield for the C tunnel plate. Hopefully it clears the exhaust. My transmission mount had some cracks in it so I am replacing that too.

Other items I am about to order are a CAGS "delete" resistor and a curt to hitch. Anything else I should buy while the car is this far apart?