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Bleeding My Clutch

508 Views 3 Replies 2 Participants Last post by  TheDinkyToy
Hey all,

So I spent the other night changing my clutch slave cylinder. First thing of many I plan on doing to my '5 (fixing first, enhancing later)

Anyway, so this evening the OH helped me bleed the clutch. I used this method:

Fill up brake/clutch fluid. Push and hold the clutch, open bleeder screw to release pressure, close bleeder screw, clutch up. Repeat lots of times.

Took about 3-4 times before the fluid started coming out. Then I continued for a while, air bubbles kept coming out, eventually the clutch hardened up properly, but while the air bubbles eased off they never really stopped, had to fill up the clutch fluid twice (never let it run out!). Eventually I gave up and closed it all up and the clutch is working well as far as I know.

My only theory is that the pipe that was on the bleed nipple wasn't fully closed and air was getting pushed into the pipe from there... possibly. Other than that I can't think what the problem was. I believe the master cylinder is fine and the slave cylinder is new. Anyway, my question is, is it okay? should I be worried?
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If you doubt that you got all the air out then give it another bleed. This time use the following method.

Fill up reservior. Put pipe on bleed nipple and crack off the nipple but not so its loose. Just so it's easy to undo when you need to. Nip it shut

Get your OH to sit in the seat and explain that she needs to do the following. You say pump. She pumps the pedal several times nice and quickly all the way up and all the way down. You say hold it down she says yes when she is pushing on the pedal. When she has said so you open the nipple when the pedal hits the floor she needs to say down immediately. You close nipple off, if needs be open and shut it before she says the pedal has hit the floor. Do this until you get no more air out of the system. It's not a long pipe so should only take 3 or 4 trys before you get solid fluid out. Needs to be quick open and shut though even if it takes a bit longer than usual it's worth a try.

The problem with clutches is that if you don't get all the air out you tend not to get full disengagement of the clutch causing drag and possible premature clutch wear.

Does this make sense? It's really easy if you know how. Sorry if you don't understand but it's the only way to describe what I know in my head.

HTH.

Kirsty.
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If you doubt that you got all the air out then give it another bleed. This time use the following method.

Fill up reservior. Put pipe on bleed nipple and crack off the nipple but not so its loose. Just so it's easy to undo when you need to. Nip it shut

Get your OH to sit in the seat and explain that she needs to do the following. You say pump. She pumps the pedal several times nice and quickly all the way up and all the way down. You say hold it down she says yes when she is pushing on the pedal. When she has said so you open the nipple when the pedal hits the floor she needs to say down immediately. You close nipple off, if needs be open and shut it before she says the pedal has hit the floor. Do this until you get no more air out of the system. It's not a long pipe so should only take 3 or 4 trys before you get solid fluid out. Needs to be quick open and shut though even if it takes a bit longer than usual it's worth a try.

The problem with clutches is that if you don't get all the air out you tend not to get full disengagement of the clutch causing drag and possible premature clutch wear.

Does this make sense? It's really easy if you know how. Sorry if you don't understand but it's the only way to describe what I know in my head.

HTH.

Kirsty.
Awesome thanks, can she do the last push a bit slower than the rest so I have time to do the open/close? I'll try this this weekend.
The pedal, once the pressure is released by opening the bleed nipple will fall to the floor quite quickly. The return spring tension will slow the travel down somewhat. I guess it's only test and adjust. If you get it wrong it will just take you a bit longer thats all, a few more attempts. Once you get a rhythm going it's really quite an easy process.

I've only ever done it wih another mechanic. It shouldn't be a problem though u just need to be ready to open and close as quick as you can giving time for the air to escape.
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