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MG MGA - Another Clutch Problem
Last Sunday morning I went for a nice drive, accompanied by my wife. Heading back home I was finding it difficult to engage gears along the way. The clutch pedal free play seemed to have abnormally increased, when nearing home, I had no clutch at all. I was only about half a mile from home, so, with the engine switched off, I engaged second gear, re-started the engine, and very slowly drove away with extreme caution. When I arrived home I pushed the car inside the garage and had a look under the bonnet. I felt that the piston inside on the clutch side on the m/cyl. was stuck halfway inside the bore. Not touching anything else I left the car in the garage hoping to have a good look the next day.
The next morning I checked the master cylinder again and saw that the piston has returned to its original position. The clutch is now functioning normally.
Only a couple of weeks ago I had removed the master cyl from the car, and honed both the bores professionally. I also replaced all the rubbers inside each bore.
I have no idea what was the cause of the stuck piston, and I am a little worried that it might happen again.
I am posting this on the forum, asking for
any help and advice from any of you kind gentlemen, members of the forum.
It can happen sometimes, if you have covered the cups in brakefluid and left it for a little while before assembling the cyl. the air gets to the cup and makes it swell a bit giving your symptoms
Sometimes they just come right on their own after a while but not very often-- but usually you have to pull it apart again and replace the cups on that piston
A good tip is to not manhandle the rubbers at all unless your hands are dead clean,and dry. assemble the dry cups onto a dry piston and only get it wet just as you go to assemble it
|Thanks Willy for you advice. From what you said I have to dismantle the master cylinder again, which of course it means that I will have to start the nasty bleeding process all over again. I dreaded that. I guess if the piston is stuck again in operation, I have no |
other alternative but to re-bleed. Bleeding the clutch is my nightmare.
Me too -I'm dreading bleeding the clutch when I change my master cylinder. I'm hoping eezibleed will do the trick as it give continual(ish) pressure rather than the short blasts with the conventional way of bleeding, that can allow air being pushed towards the bleed nipple, but then returning back to where it came when the pedal is released.
There is also an interesting moss video worth a view if you havent seen it.
If you do the MC tilting trick and not disconnect the pipes you may get away without the need to bleed. Just give the unit time to settle after you have finished to alow it to bleed itself. Worked with me.
|Thank you Graham & Steve for your input. If in the end it comes to a rebleed of the clutch, I shall follow Steve's advice and tilt the M/cyl. to avoid another bleeding process. However, I decided to leave things the way they are for now, and not touching anything for the time being. I have placed a small strong piece of wood and a small ball peen hammer in the boot of the car, and if there is a repeat of the problem, I will be able to tap gently on the master cyl. body hoping that the piston will shift back to its position. If it is found that the problem is recurring then I'll have no choice but to replace the rubbers on the clutch side.|
|On some slave cylinders that are giving a problem bleeding I have found that by un bolting the slave and let it dangle for a few hours the bubbles will work their way up and out.Some times it takes a day or so.|
|I had the clutch piston stick again halfway inside its bore. Naturally that means I shall have to replace the rubber seals. So, the M/C tilting trick, as mentioned by Steve Giles, will have to come into force. I certainly do not fancy bleeding the clutch again. One question for Steve, if I may, am I right in saying that before tilting the cylinder I have to syphon some of the fluid out? Your reply will be appreciated Steve.|
|Attention Steve Gyles.|
Steve can you please have a look at my last post on this thread. Many thanks.
It will help to syphon some of the fluid but you should not need to empty the chamber. Just sufficient that when you tilt the MC there is not a mega flow out of the front when you withdraw the piston. Only really an issue with Dot 4 type fluids that could damage the paint work. I have silicon so that is not a problem. I just place some rags under the unit to soak up any spillage.
|Steve, thank you for your kind reply. Sorry for being a nuisance. I too have silicone fluid in the system, and old rags pose no problems to me. I will be flying off to France visiting my son & his family, the week after next. So, I will tackle the M/C when I get back in July.|
This thread was discussed between 02/06/2017 and 12/06/2017
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