tpnguyen

I have a 95 GXE w/ manual transmission and a slipping clutch. Here's the history of the problem:

Around Sept. of last year, I lost clutch fluid due to a leak of some sort, which hindered my ability to change gears. Took it to the dealer, and they said my slave cylinder went out. Had them replace both master and slave cylinder (just to be safe). Worked fine for a couple months, but then, over the X-mas holiday, lost all my clutch fluid again (maybe I should check it more often). Had to take it to a different dealer since I was out of town, and they said there was a leak in the hose connected to the slave. They bled my clutch and added fluid, and told me to take it back to the first dealer to fix the leak since they didn't have the part. On the way back home, the clutch started slipping. So, took it back to the original dealer to fix the leak and the slipping clutch. They replaced the hose and replaced the clutch disk/pressure plate (which needed replacement anyways, had 130K+ on it). Unfortunately, it still slipped. I've taken it back at least 5 times, and so far they've given me yet another new slave cylinder (because they thought it was leaking and letting air into the system) and a new clutch disk/pressure plate (because they believe it was installed improperly the first time). I'm going to have to bring back in again because it's still slipping, and nobody knows why it's doing that. Do you?

Description of the problem:

When the car's been sitting for a while (say, overnight) it drives fine, and the clutch feels light with uniform pressure. It engages at around a third of the travel distance from the floor. After about fifteen minutes or so of driving, the clutch pedal travels higher and higher before it engages, until it's almost at the very top. Here, the clutch starts slipping under acceleration (identified by increased RPM without an increase in speed), and especially when switching gears. I've also noticed that the pressure is no longer uniform, in that the first half of the clutch pedal travel requires more pressure and is more "springy" than the bottom half, and snaps back a lot harder at the top. The problem goes away after the car has cooled down (again, overnight), and starts back again after about fifteen minutes.

Sorry for such a lengthy story, but I hope I've given enough info for someone out there to figure out this problem. If you have any ideas, please let me know!!!

P.S. - I've made one modification: a B&M short-throw shifter. This couldn't possibly be the root of all my problems, could it?

sryth

Hmm...pretty confusing.

The only difference (you've noticed) between when the clutch slips and when it doesn't is that the engine is warm.

The only things I can think of are:

1) Maybe a seal is going...and it's letting oil through when it gets nice and hot.

2) Long shot: Maybe there's air in the clutch system that expands when it gets hot. Clutch is fine when it's cold, but when the air expands it partially disengages the clutch.

Have you noticed any oil on the ground after driving?

If you have some time, try this: Have someone push the clutch pedal to the floor while measuring the distance that the clutch fork moves. Drive around for 15 minutes and do it again...does it move less?

I don't know how accurately you'll be able to measure this, though.