T-Series Can't disengage clutch

[jimmiekeyes]

I have a 1980 MGB with hydraulic clutch. It wouldn't disengage so we just finished rebuilding the master and slave clutch cylinders. We bled the system carefully and reinstalled both cylinders. the Master cylinder is full and there is no air in the system. The slave cylinder travels just about 1/2 inch and the clutch simply will not disengage even after all the rebuilds.
We know it could be a bad clutch but the clutch grabs so solidy it is hard to believe that is the case
HELP!!!!
Jim Hurley
jdhkeys@terranova.net
305 853-1215
Tavernier, Florida

 

[Guest]

Clutch plate could be rusted to the flywheel. Has the car been run recently?

 

[Gunner]

Gerry
How can that be checked? Any way to get to the thing and free it up>?

 

[Guest]

Some folks tow the car in high gear with the clutch pedal in and hope it frees up. Others suggest jacking the rear up, crank the engine up and with the pedal in and the tranny in 4th, use the brakes to add load until the clutch breaks free. I cannot promise results from either. If neither of these work then it may mean pulling the engine for a clutch job. How did this happen? Car sit up for a while or did it just happen over a short period of time?

 

[jimmiekeyes]

The car was running and slowly began to become difficult to shift. It is used every day so no rust. we concluded that the rebuild may not have been sufficient and I've ordered a new slave cylinder and hose. We had an awful time getting the hose to come off the car and never could get it off the old slave cylinder. So our intention is to pop the new slave cylinder on with the new hose and bleed it again,
Hopefully that will give us enough throw on the clutch to disengage. Right now the best travel we get on the slave cylinder is 3/8ths of an inch. Nowhere near enough.
Jim Hurley

 

[Guest]

Hope that works for you. Normal slave stroke is about 1/2 to 5/8". If you are only getting a partial stroke this may be your problem. Good luck!

 

[piman]

Hello Jim,
it does sound as though your problem is related to the slave cylinder\hose. It shoud be possible to operate the clutch arm using a lever to eliminate the possible clutch rusted to the flywheel. Jack up the back, with the car in gear, use a lever and operate the clutch and see if the rear wheels will turn. If so the clutch is mechanically ok. Another possibility is a problem with the release arm but the above check should tell you that.
The easiest way I have found to release a rusted clutch is to start the car in gear, keep the clutch down and accelerate and brake simultaneously (heel and toe) It helps to warm the engine up first.

Alec

 

[maynard]

I had a similiar problem. Turned out the driven plate fractured and a piece lodged between it and the pressure plate.

 

[Moose33]

Morning..

Did you figure out your clutch issue?

If so, did any of the above methods work?

I'm asking 'cuz mine is just the opposite, won't go into gear (grinds). But I'm reading the posts and will be trying some of the tips Sunday.

 

[MattP]

Moose, I feel your pain, I just had the same problem with my 77 B start suddenly today. I posted before finding this; I will be anxious to hear how the tips work out.

 

[aeronca65t]

Check the lines that connect the slave cylinder to the clutch (flex and metal line). I just changed one in my brother's Midget that had a tiny pinhole in it. The clutch would work just a little bit and then get worse until more bleeding. Very frustrating.
Bleed from the top of the system: by this I mean that you have someone pump the clutch up and down, hold it down and loosen the hose-fitting that goes into the clutch master cylinder(and then tighten it before releasing the pedal).
Air sometimes gets trapped in the high end of the system and this will get it out.
Also, be sure that the clevis pin and hole (at the top end of the clutch pedal) are not worn. A tiny bit of wear in this area translates into a lot of lost mostion.