engine and drivetrain Problem With Clutch...

[jamesb]

I'm having problems switching gears on my 76 '02  - it often grinds when I'm shifting, or won't go into gear at all.  When it's turned off, it slides into gear, no problem, but once I turn it on, and with the clutch in, it's in gear and starts moving (or stalls).  Definitely need to take it in for repair, but thought I'd get some insights first, so the shop doesn't take advantage.  What do you all think - new clutch, adjustment, or worse - something up with the tranny?  Thanks.

[bmwfan]

Does the clutch pedal have any free play, moves down freely before any resistance, if not, then maybe need an adjustment. Should have 1 to 1.5 inches of free play.

Did this just start? ECT...... What's the pedal " feel " possibly clutch slave cyl.

[jamesb]

Thanks for your reply.  Yeah - it moves pretty freely - very little resistence.

[Kile Brekke]

It's possible that the slave cylinder has air in it, or is leaking. 

When I first got my car it constantly would get air in it, but would not leak actual fluid. 

This confused me at first which made me think horrible thoughts about the clutch or transmission itself. 

 

I would pump the clutch rapidly before attempting to downshift or come to a stop to mitigate the problem. 

 

I also noticed while driving on the freeway, if I kept the clutch depressed about a half inch or so, it would not suck air and would keep the hydraulic system air free. Almost the like it was keeping subtle pressure in the line to not allow air in. 

 

I can't exactly explain it, but it worked temporarily for me before I had the slave and master cylinder replaced for good measure. 

[jamesb]

Thanks for you post, Kile - I'll try that as well!

['76mintgrün'02]

While you are under there, peek inside the pedal box, or look for wetness on the under side of it.  My clutch master cylinder was leaking when I got my car, as was the slave cylinder.  My fluid level in the reservoir would drop to the level of the outlet for the clutch system, due to the leaks.  I also had considerable rust to repair in the driver's side floor and the pedal box itself.  I bought a pedal box rebuild kit while I was at it, due to a broken spring and worn bushings.  One problem can lead to many repairs, but the end result is quite gratifying.

[Mike Self]

Since your '76 has a one piece carpet, making it difficult to check the inside of the pedal box without pulling the carpet, take a pencil or popsicle stick and poke it down next to the clutch or brake pedal into the pedal box.  If it comes up wet, your clutch M/C is leaking.  That pedal box will hold over a pint of brake fluid before it overflows (ask me how I learned this!).  

 

I suspect from your description you have a leaking clutch slave or M/C.  If you find one is leaking, I'd replace both, as what you don't replace will become the weak link, and the new part will hasten the old one's demise.

 

cheers

mike 

[TobyB]

Yeah, sounds like a problem in the hydraulic system of the clutch, for sure.

Not too hard to work on, and a good place to start learning to work on your

own car, as the shop rate for a repair is going to be at least 50% labor.

 

Kile, when the seals in the master and slave wear or shrink, they

do exactly what you describe- if you pump the pedal quickly, the

seals will get pressed out against the edge of the bore, and seal.

But if it gets a chance to relax without pressure on it, then it can start

leaking, or draw air.

 

t

[Kile Brekke]

Kile, when the seals in the master and slave wear or shrink, they do exactly what you describe- if you pump the pedal quickly, the seals will get pressed out against the edge of the bore, and seal. But if it gets a chance to relax without pressure on it, then it can start leaking, or draw air.

 

 

Toby, thanks for the technical explaination. 

I got so used to keeping my foot resting on the clutch pedal slack that even now—2 years later—I still sub-consciously find my foot drifting over to rest on the clutch while on long drives. 

 

I guess I just feel so guilty giving it a proper rest on the floor!  

 

Jamesb, 

Moral of the story is, if you are not visibly leaking fluid from a worn out hose, or connection, and find that pumping the pedal temporarily helps your issue, then either one, or both of your cylinders are most likely bad. Either way, it would be prudent to do them both at the same time. I took advantage of the scenario to also replace the flexible lines out of the reservoir—mine looked like a shredded chinese finger trap.