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MG MGB Technical - Clutch slave piston popped out!

So my daughter is helping me bleed the clutch on my '77 B. She may have been pumping the pedal a little aggressively (not sure on that), but all of a sudden the slave piston popped out and got itself stuck a little sideways in the cylinder.

I just wondered why it would have done that. Any ideas?

Thanks in advance,
~Dave
David Steverson

The only way this can happen is if there is a problem in the bell-housing i.e. the release bearing has broken or some other failure in the mechanical linkage between slave push-rod and cover plate, or possibly the flex hose is acting as a check valve and so wasn't letting the slave piston return with the pedal, so further operations of the pedal were adding fluid to the slave, rather than the same fluid going back and fore as it should. It only takes a couple of pumps in either of these cases for the slave piston to be pushed out of the end, normally it should stop about 3/4" or so from the end. Unless this had just started happening it would be detected as sluggish engagement of the clutch in normal driving.
Paul Hunt

Paul, you "hit the nail on the head". I just came from the garage after pulling the clutch fork dust boot. The release bearing came off the clutch fork end somehow.

Great.

Now I just have to decide whether to attmept just pulling the engine or the rengine/transmission as a unit.

Regards, David
David Steverson

I know a lot of people recommend pulling both together, but having done just the engine I wouldn't do it any other way as I can't see how I could have pulled both using the trolley hoist I had. Even pros with a roof hoist only pulled the engine, saying the least interference the better.

Whichever you do, if the clutch flex hose is an unknown quantity I'd strongly recommend changing it while the engine is out, it is a pain with it in, and can be nigh-on impossible if the nuts around the chassis bracket are corroded.
Paul Hunt

Interestingly Paul, I had read all those archived comments about pulling the engine seperately or as a unit. I have never tried the former, so I gave it a go.

Yesterday was a holiday here in the US, and I used it to pull the engine only, fix the bearing issue and re-install. It took me about 5 hours total (with no help), counting stopping for a leisurely lunch break.

I am now a firm believer in the engine only (when needed) camp.

I am going to replace that hose this week, but will have to do it the hard way as the engine is back in. Oh well.

~David
David Steverson

Well David I have to say you don't muck about, do you?
Thread started 6th, problem confirmed 7th, engine out and back on the 8th. A very impressive performance.
Don't suppose you hire out your skills?
Regards
Roger
Roger T

This thread was discussed between 06/09/2009 and 09/09/2009

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