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brake causes clutch to stick.

Posted: Wed Nov 28, 2012 7:38 pm
by eth
Hi all, I have been a proud moggie owner for just over two months now and I have noticed a bit of a rock between the brake and clutch, this has now developed into a bit more of a problem. If the brake and clutch are depressed together the clutch won't return until the brake is released, rather concered as I heavily rely on engine braking as I'm sure the rest of you do ... save thoes with servo discs. I would go out and investigate but the weather is more than discouraging at the moment, also a good chance to thank everyone for this great forum to which I hope to one-day contribute. So, I put it to you.

Many thanks in advance, Ethan.

Re: brake causes clutch to stick.

Posted: Wed Nov 28, 2012 8:10 pm
by simmitc
Easy diagnosis: worn clutch pedal shaft and/or worn bushes in the brake pedal. If you look at the parts list, you will see that the brake pedal sits on the shaft for the clutch pedal. Long term solution is to replace the worn parts. Short term, you might get away with a light lubricating product such as WD40 or 3-in-1 silicone. You can remove the small cover over the master cylinder in order to get access to lubricate the offending parts. When you are ready to renew the bushes, I recommend doing all the clutch linkage at the same time, as it is almost certainly worn as well.

Re: brake causes clutch to stick.

Posted: Wed Nov 28, 2012 8:33 pm
by lowride stepside
Its worth a squirt

Re: brake causes clutch to stick.

Posted: Wed Nov 28, 2012 8:40 pm
by bmcecosse
As above - oil it! And check the return spring is present on the clutch linkage. But if you have to rely on engine braking - your drums are in need of a good overhaul! The 8" front drums are very definitely ok for sane Minor motoring. The 7" drums are a bit more marginal - but should still stop you - once. They just may not do it over and over again going down a long hill..... :oops:

Re: brake causes clutch to stick.

Posted: Wed Nov 28, 2012 9:18 pm
by MarkyB
WD40 is too thin to do any lasting good, get the master cylinder cover off with a screwdriver that really fits, after removing any muck in the screw head.
Then you will be able to see what is going on and apply something better to the affected area, 3 in 1 is good, maybe followed by a dab of grease for long lasting lubrication.

Re: brake causes clutch to stick.

Posted: Thu Nov 29, 2012 12:12 am
by eth
If you said my brakes needed o/h 2 weeks ago I would have definitely agreed with you; rusty, leaky, spongy, warped, worn and crumbling would describe them in a few words (most of them also applied to the suspension). Trust me I'm not laughing I can't believe it passed an mot, it won't need one of those pointless things again thankfully.

She is a 1958 traveller (daily driver) uprated with 1098 engine, g/box, axle and 8" brakes. With all the work I've done on the brakes and suspension she stops and handles pretty well, so as engine braking is concerned I just love to hear that raspy note :D

I didn't change the master cylinder when I did the brakes, I ran out of weekend and it isn't giving trouble, although I will be changing it out of precaution in the next week or so. Sounds like it might be preferable to replace the m/c and fix the pedals properly at the same time while im there. Will report back with findings soon!

Re: brake causes clutch to stick.

Posted: Thu Nov 29, 2012 2:32 pm
by mike.perry
If the master cylinder is OK leave it alone. Changing it is not a job to be done for fun

Re: brake causes clutch to stick.

Posted: Thu Nov 29, 2012 11:59 pm
by oddbod
I know this is sacrilage, but I was told by someone who has kept Moggies going in the past, that it was easier to cut a piece out of the chassis, replace the Master cylinder then weld the chassis up again, not one for a Concours car, but OK for a daily driver!! :wink:

Re: brake causes clutch to stick.

Posted: Fri Nov 30, 2012 12:07 am
by bmcecosse
Nonsense! Where do you hear such rubbish??

Re: brake causes clutch to stick.

Posted: Fri Nov 30, 2012 10:34 am
by simmitc
~I agree with Roy. Complete and utter rubbish, "advice" of the worst kind.

Re: brake causes clutch to stick.

Posted: Fri Nov 30, 2012 11:25 am
by ASL642
Well I must admit that's a new one on me - never heard that "advice" before! :roll:

Re: brake causes clutch to stick.

Posted: Fri Nov 30, 2012 11:26 am
by oddbod
Why rubbish? I am aware that changing the Master Cylinder is a difficult job, and not always successful,why not make it easier by cutting out a piece of chassis and replacing?

Re: brake causes clutch to stick.

Posted: Fri Nov 30, 2012 2:00 pm
by JOWETTJAVELIN
And what happens when the bodyshell distorts due to having taken a massive chunk out of the structure?

Sounds like cowboy mechanics of the worst kind.

Re: brake causes clutch to stick.

Posted: Fri Nov 30, 2012 7:49 pm
by eth
I understand that the m/c is a fiddle but that seems a little extreme cutting the chassis leg sounds more like desperation. Also is it good advice to discourage me from changing a pattern m/c of unknown age? It didn't look like anyone had touched it in years :-? Do they fail without warning?

Re: brake causes clutch to stick.

Posted: Sat Dec 01, 2012 8:21 am
by MarkyB
Not normally, the seals wear and they start to leak.
Air constantly getting into the system when you are trying to bleed the brakes is another symptom.

Instant brake failure is caused by a hole or fracture in one of the pipes including the flexible ones.

Re: brake causes clutch to stick.

Posted: Sat Dec 01, 2012 11:51 am
by Trickydicky
I replaced mine last year, I followed the instructions in the technical help section and on my own did it in one day, the biggest problem I had was getting the airlock to move to enable me to bleed the brakes. Once that was done I would say replacing a M/C is not the trauma some make it out to be.

The biggest reason why they fail is due to the bore of the M/C becoming rusty and pitted which then causes leaks. Rather than fit a seal set I would personally replace the M/C for this reason.