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MG Midget and Sprite Technical - Clutch Woes
|Just taken my Mk3 midget out for its first run this year, and the clutch pedal had very little movement before biting. Some gear changes wouldnt happen (bit of grating when moving gear level although clutch pedal was fully depressed) until I pumped the pedal a few times.
The m/c is full, is this problem hydraulic and where is the best place to buy new m/c and s/c if needed. I would sooner fix the problem with a one stop shop, Ive had the car for 15 years and nothing clutch wise has been trouble or replaced in that time. Thanks for any advise.
|Just sounds as if it needs bleeding. But if it's been a while since it had any attention I would drain and refill the system first and then bleed it properly. I also wouldn't dive in to replace master or slave cylinders until I had tried bleeding it as is. Unless, possibly, there is black debris showing in the m/c reservoir,?|
|Yes I would try bleeding first, although if it was OK the last time you used the car I would not think that air could get into the system while laid up. It sounds more like worn rubber seals to me. Usually fitting a repair kit is a cheap but laborious job. If you have to do that, inspect the M/C bore carefully as the bare steel ones can corrode inside, especially when inactive. If you are still pumping the pedal after that, then look at the slave cylinder.|
|L B Rose|
|A thorough flush through and out and full change of fluid if you can't remember when you last changed the fluid.|
Also what about the rubber flexi-hose, if not changed in 15 years, or probably especially if replaced, then I'd change that to a Goodridge type PTFE (instead of a modern made potentially piss-poor rubbish rubber type).
|Thanks all for advice. I will check colour of fluid, and flush and bleed first. I was assuming seal problems, hence looking to maybe change both cylinders. If fluid change sorts it and pipe work looks OK I’ll leave it at that, then change m/c then s/c if necessary. I would like advice on best place to buy new cylinders. If I have to go that route I will be back to ask questions regarding remote bleed screw as I understand that makes things easier.|
|Hi Colin you may already know this but I've cut a slot leading up to one of the bolt holes in the clutch slave. Makes it sooo much easier to get the slave on and off. I read it somewhere so can't claim credit . If you are interested I'll send a rough drawing|
And I keep meaning to do the remote bleed device but I'm still hurting my back and fingers doing it through the slot or underneath.
|B M Le Page|
|Powertrack Ltd is a good source of high quality brake and clutch components including clutch slave and master cylinders: https://www.powertrackbrakes.co.uk/index.html|
Ideally look for original equipment Lockheed (these days 920 Engineering, was recently known as AP Caparo).
|Remote bleed for the clutch.|
This is on a type 9 box with home made concentric slave cylinder but the principle is the same. When adding to a normal slave cylinder use a rear brake hose and it is a convenient length and has the correct fittings at either end.
|Once again, thanks for advice.|
Brendon, I would appreciate a drawing of slot mod.
Mike, Powertrack contacted for a quote.
Guy, required hose noted and added to above quote.
My son, a motor vehicle technician will be assisting me (he is better at getting under cars than me) but it will be a week or two before he can so I will be quiet for a bit!
|Quick fit slave and remote bleed system.
|If it turns out that your carbon thrust has failed you may want to consider a roller release bearing.
If the car has been sitting unused for a while it 'might' be a bit of rust on the flywheel making the clutch plate drag
If you go up the road and slip the clutch a bit in 4th gear, if it is a touch of rust doing this will clean it off and fixit
|Willy, it does tend to “rust” together during winter. I have on occasion had to get engine nice and hot and wedge clutch pedal down overnight to free it. I will take it out and slip the clutch a few times before I do anything I think.|
I do wonder if leaving it “under pressure” for a period affects the seals, but it seemed a gentler method of freeing clutch than some recommendations.
I like Willy's idea -
. it an easy, simple, no cost thing you can do in comfort
. it involves driving the car instead of just farting about with it
. it keeps your hands and rest of body clean
. it saves anyone from grovelling around on the ground
. it saves potential for bodily damage and causing aches and pains.
If that don't work I'm still for firstly replacing the fluid with a thorough flush and replacing the flexi-hose with Goodridge type, which you could use something for the simpler potentially longer lasting remote bleed hose.
I'd avoid anything that involves modern made potentially piss-poor rubbish rubber like rebuild kits of rubber seals, new m/c and s/c with modern rubber seal, rubber flexi-hoses. They might be all fine but why risk replacing your existing potentially good m/c and s/c. I'd bin the existing rubber hose for the sake of present and future confidence with a fit 'n' forget Goodridge type flexi-hose, that's what I did 13 years ago with my clutch (and brake) flexi-hoses.
Photo is of the bleed valve fitted to mine, a variation of the idea, I release it from its p-clip holder and have it drain into a (curry sauce) jar resting in the engine bay so I don't have to get down to get dirty.
Just a suggestion but if you fix your bleed to the engine it removes the risk of stressing the pipe.
|I thought that at first as well, Alan, but then I think Nigel has used a Goodridge type of braided flexible hose.|
|ETA: didn't see Guy's post, yes and yes.
Thanks Alan I never thought of that but the photo is before I turned the p-clip to give an arc to the hose and fitted a nipple cap, it might not show but there is plenty of slack on that hose.
Most will want to look away now as I winge again about quality control, my bad luck, paying professionals to do work and my lack of physique.
There, that cleared the room, I can moan to the wall.
The remote isn't where I thought it'd terminate or as short as I expected but having to take the (les than 2 year old) Titan concentric slave out myself because I got one of the two in 20,000 units over 20 years that was faulty (neoprene instead of Viton seal fitted when manufactured), and fitting a closing grommet that had been missed out by the bodywork man doing mechanics, I know there's plenty of slack on that hose, the engine would be knocking on the bonnet before the slack was lost. Plus its this plastic inner not rubber.
I did consider replumbing the supply to and vent from the slave with more mix of solid pipe but as I was totally pissed off with it before I started and literally suffered from working too long in a dampish extremely cold mate's garage I left it as it was.
|Just an update on progress:
New master and slave from Powertrack fitted. Ordered a rear brake hose to fit a remote bleeder but didn’t need it a an access hole fitted with a rubber plug exists beside the clutch pedal and allowed my son to bleed through the original nipple (the old fashioned way as he forgot to bring his pressure bleeder)with me underneath checking for bubbles. After two bleeding sessions now have a working clutch, but would like the biting point a little higher. To this end we will reconvene in a weeks time to pressure bleed, after a couple of short runs with a bit of clutch slipping during the week.
Thanks to all for help and advice.
|Why not have a transparent tube, one end on the bleed nipple, the other end poked into the top of the master cylinder. No chance of leakage and no chance of emptying the master cylinder.|
|You could do that with a complete new system like mine was, apart from the pipe between cylinders, but we bleed into the same jar we drained into. Also any drips from the tube fell to the ground and not in the engine bay. We did keep checking the master cylinder level.|
|With the quality (or otherwise) of new seals even with a completely new parts there can be discolouration of the fluid if not muck so I'd not trust the loop direct from bleed to master cylinder as you're not flushing out the fluid and what it contains.|
Perhaps I'm being too picky.
But I've put litres through and out of the clutch on mine whilst cleaning the master cylinder yet it's not taken long to start discolouring and fluid getting black within a number of months.
|I always find that when bleeding the fluid that comes out, along with any air, also has lots of almost microscopic air bubbles in suspension. I wouldn't want to feed that back into the master cylinder.|
|Glad it's sorted Colin. I had similar issues and like you, finally resolved by a new Powertrack supplied NOS Lockheed master cylinder, a Rimmer Bros supplied Taiwanese slave cylinder and a new 3" slave cylinder pushrod, which had been in the spares box for a while. It took a day or two usage to shake out those microscopic air bubbles still present after a couple of bleedings. |
Can recommend the vacuum type bleeders for ease of use and speed especially with a remote bleeder.
|As it happens I just had a roughly similar issue. Master cylinder suddenly leaked badly. I did the usual repair job, but could not get the clutch to disengage. About 0.5L of fluid went through the system and no more air was coming out. I lost my temper and pumped the pedal vigorously about 20 times. After that the damn thing worked. I think the problem is that new seals are a bit sticky at first and the spring behind the piston can't return it quickly enough, so next time you press the pedal it's in the wrong position. I can actually hear the brake piston slowly returning while bleeding.
|L B Rose|
This thread was discussed between 12/04/2021 and 09/05/2021
This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.