When I am stopped (at a red light, for example), the car wants to lurch when in 1st gear, even though I have the clutch pedal fully depressed. I know this is not a problem with the clutch master cylinder leaking by where you lose pressure on the pedal. Car has 245,000 miles and still has original clutch. Car/transmission work fine so long as I put it in neutral when I stop. Doesn’t seem to do this w/reverse. Clutch also passes the “stall test” where you let it out in 4th gear with the hand brake on. What’s going on here?
What makes you think there’s not a problem with the clutch master cylinder?
Tester
I have had that problem before with other cars. When you hold down the clutch pedal in that case the fluid leaks by and you lose resistance in the pedal and it just sits flat on the floor.
If the leak is slow, the clutch slowly engages as the leaking fluid allows the clutch arm to move. but it should do the same thing in reverse…
In any case, you shouldn’t be riding the clutch waiting for the light to change…
Another possibility, the pilot bearing gets hot and starts seizing up, that’s the tugging you feel…But again, should do it in reverse too…
I read my Haynes manual and it said to check if the clutch was releasing by putting the hand brake on w/ engine running let the clutch up about a half-inch and see if the shifter would move smoothly from 1st to reverse and back again several times. It passed this test. I like the pilot bearing theory, though, even if it’s not doing it in reverse, because the problem is intermittent.
You could have a problem with the clutch disc with loose friction material that is grabbing against the flywheel or pressure plate; with loose antichatter springs near the hub; with intermittant runout of the disc because of structural failure; or with dry, gummed up, splines in the disc hub and/or transmission input shaft.
Sometimes you have to go a a fishing trip to eyeball the exact cause. At least you would have a new clutch disc, TO bearing, pressure plate, and pilot bearing.
The problem is you have to pull the engine on this car to get to all that stuff.
Try putting the transmission into reverse when the engine is hot with clutch pedal depressed. If the vehicle starts to creep backwards the problem is with the clutch master cylinder.
Tester
This clutch has gone as far as any good one should.
It’s earned retirement.
I would change the master and slave cylinders too after 18+ years.