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MG MGA - Clutch problem

I have a 1957 MGA 1500 and I have the following problem with my clutch:
- on 3 occasions pressing on the clutch has resulted in pushing the piston in the slave cylinder totally out of the end of the slave unit and causing the clutch to lock in the disengaged position.

Is there any way to adjust the position of the lever arm on the clutch itself so it reached further into the slave unit?

Do I just need to adjust the master cylinder so that it does not push so far.

When the clutch is working the point of engagement is very close to the floor - i.e., you only let up the pedal about a half inch. Maybe this is the way it should be.

I am going to reload the slave unit and bleed the connector to the master cylinder again to see it this will happen again.

Recently it seemed to work well, then when the car was hot it made a binding noise when the pedal was fully depressed - then it blew out the cylinder and was stuck --- resulting in the need for a tow!

Any advice would be appreciated.

Thanks,
Bill Chandler -- Ann Arbor, MI
W Chandler

Sounds like a faulty flexible hose acting like a non return valve?
Mike
Mike Ellsmore

Sounds like damage or wear in the release bearing lever to pivot and/or slave cylinder piston pushrod to release bearing lever. Probably also a worn release bearing face.

A fairly common problem given the age and mileage on our cars.

The result is too much slack in the release bearing mechanism requiring too much travel in the piston and hence pedal.

It could also be (compounded by) the hose as Mike suggests, but swelling rather than acting like a valve.

Everything except the hose and the pushrod/pivot requires engine removal to fix!
Neil MG

I will go along with Mike Elsemere. Check your flexi hose, it could very well be partially blocked. Is the pedal very hard to push?

Frank
(Mike looking forward to meet you)
F. Camilleri

Bill

I had to be towed open after pushing the piston out of the slave cylinder. I am afraid in the end I did take the engine out and I found there was wear in all possible places, some quite significant. A couple of points:-

1) There is one bit of wear you can fix easily and that is the pivot hole in the pushrod itself and also the pin can also both be quite worn. So check and if required replace rod and pin.

2) I am afraid the length of replacement rods seem to vary quite significantly so perhaps you can get a longer rod that may help in the short term.

3) I have a friend who has been in the trade for 40 years and he told me a trick. When in the old days this arrangement was more common the mechanic would take the rod out and hammer a nut onto the end of the rod. Not only did this make the rod longer but as it goes into the 'V' of the piston making it wider makes if effectively longer again. When I took my rod out after my failure I found it already had a nut hammered on the end, but it had still failed as the other wear was so bad.

The above will at least help in diagnosing the issue and also should give you enough improvement to see you through the summer driving season.

Paul
Paul Dean

Bill, when it first happened didn't you at least give the clutch arm a wiggle by hand to check for bush wear. I take it this problem did not just happen , it must have been bad for some time!
Mike
Mike Ellsmore

I had a friend that had this problem. The first time he pushed in the clutch it worked fine but the second or third time it would push out the piston. His rubber hose was bad and it would let the pressure go to the slave cylinder when you pushed on the peddle but would not let all the fluid go back to the master cylinder when you released the peddle. After replacing the hose it worked fine and is working fine after a year.
GK George

I was very fortunate that the same thing lead me to my first MGA.
It was way back in 1973 and I spotted an MGA in a motel parking lot with a for sale $75.00. Motel owner said that he was tired of replacing transmission twice in the last year and his son was not driving it any longer.
It was a Friday about 10 AM and I towed the car to my store. I drove the car home at noon to show my wife our new car.
YOU GUESSED IT. Clutch slave had popped out jamming the clutch open.
Our daughter learned to drive on that car and the clutch gave no further trouble.
Sandy
Sandy

Mike Ellsmore, sorry for the wrong spelling of your name.

Frank
F. Camilleri

This thread was discussed between 06/07/2015 and 07/07/2015

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