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MG MGA - Clutch woes

I'd welcome comments on a perplexing issue I have. By way of background, the car was running fine on Saturday morning & afternoon and I took part in an MGA run of around 120 miles or so organised by the MG Car Club Scotland (by regular BBS contributor Paul Dean). A great run (albeit in some pretty wet conditions) and including a pretty arduous steep hill climb with sharp hairpins. The car managed this climb pretty well and drove for another 30 or so miles thereafter to the rendezvous cafe at the end of the days run. On leaving all the other MGAs at the cafe the clutch seemed a bit stiffer than normal and a few miles further on going back home there were the signs of the clutch slipping and nursing it home was unfortunately out of the question. A recovery vehicle picked us up and trailered the car back to Edinburgh. The clutch pedal is now very stiff and it does not seem to be moving the slave cylinder rod. The master cylinder push rod has the recommended play/movement (circa 1/8th inch). The clevis pin at the end of the slave clyinder push rod is bound & tight and can't be pushed manually. Plenty fluid in the master cylinder. Both the slave cylinder and hose have been replaced within the past 12 months. I'm keen to establish whether worst case I need a new clutch (have I burnt out the clutch doing the steep hill climb?) or do I simply have a hydraulics issue? It seems as if somehow the clutch could is stuck somehow in the disengaged position? My next steps were going to be to replace the slave hose again, re-bleed, and see if there is any improvement/resolution. I'm a relative newbie to these cars - any wisdom on the matter would be very welcome! Thanks. Tim, 1961 Coupe Edinburgh
Tim Prime

I would do the easy check first, crack a joint in the clutch hydraulics and see if the pressure in the system relieves. If so, then the problem is hydraulic, and will probably not be your new hose.

Check the hose anyway just because it's easy. Then look to see if the piston is cocked / jammed in the slave. Remedy is a new slave of better quality (steel piston, not aluminium)

If all is good, take out the master cylinder to check all is well inside. I had problems in Croatia a few years ago and on dismantling found that the primary seal on the MC brake side had come out of its groove and the piston was cocking slightly in the cylinder and causing leaks and strange clutch behaviour. I also noticed that the pedal spacing was causing a non-parallel action of the MC pushrods, and this is something I still have to address.

If the MC is good, only then does it make sense to take out the engine and see what is happening with the clutch
Dominic Clancy

Dominic.
Your info regarding stuck piston brings back old memories.
It was early one friday morning and I saw an MGA for sale $75.00. It looked very good neat and clean without any body rust at all. On talking to the owner he said it's a bad transmission and during the last 12 months I have paid to have that transmission rebuilt. It's gone again and my son will not have it any longer.
I purchased it and towed it home . Before lunch that day I was driving it and all was well. The clutch slave piston was half out and jammed. All it took was pushing it back in and bleeding.
I found that the push rod was too short allowing the piston to pop out.
My daughter enjoyed it for the next 5 years without any major problems at all.
Sandy
Sanders

Thanks both. I'll tackle in the sequence suggested by Dominic and report back on findings/progress. Might be a week or two due to other commitments. Cheers. Tim
Tim Prime


Following my breakdown the other Saturday I'm pleased to say that it doesn't seem to have been the clutch that was the problem. The slave cylinder piston was stuck somehow and once I'd removed it a good clout released the piston. It had only been installed last year so maybe it was defective in some way. I've replaced it and also the hose (which was also new) and all seems much better although I've still to take it out for a proper run to go through all the gears. A bit of tweaking also still needed to the length/travel of the clutch rod at the master cylinder.

Thanks for all the advice & encouragement.


Tim
Tim Prime

This thread was discussed between 31/07/2019 and 18/08/2019

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