Bleeding a hydralic clutch

MEMBER
AUDI A4

Is there a special trick to bleeding the hydralic clutch. We installed a relacement 5 speed and used the original slave and master cyl. And cannot seem to get any good fluid flow from the bleedr. I have even applied about 10 p.S.I. To the resivoir to force fluid but still unable to obtain any pedal.
1998 audi a4 v6

6 Replies

MHPAUTOS

MECHANIC
31,937 POSTS

Hi there,

As long as the master & slave cyl are in good order there should be no reason why you don't have a good pedal. Now bleeding a clutch is a bit different to bleeding brakes. To bleed a clutch top up the fluid, depress clutch, open bleeder, with pedal still on floor, and with fluid / air expelled close bleeder, raise pedal and re peat 5-6 times, or untill no air is evident. If you can not get a good pedal after this you have air entering the system some where so you will have to inspect the relevant cylinders for a problem.

Mark (mhpautos)

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Sunday, September 9th, 2007 AT 12:50 AM

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Sunday, September 9th, 2007 AT 8:37 PM

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Sunday, September 9th, 2007 AT 8:40 PM

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Hello Mark,
After removing the slave and master cyl. I discovered I was not getting fluid from the resivoir to to master cyl. What I found was the nipple on the reservoir where the hose connects was still closed off from the factory which did not allow fluid to flow to the master cyl. I appreciate the time you spent and much thanks appreciated. All is well and have a happy customer. That was a first for me especially since the car has 140,000 miles and has had the clutch changed once before.
Thanks again, Bob

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Sunday, September 9th, 2007 AT 8:47 PM

DOUBLEDART

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On Audi A3 1.8 the master cylinder was renewed. Bleeding was tried by pedal pressure - then venting which did not work. Back bleeding by injecting fluid into the vent screw - this gave half to full pedal which varied for no apparent reason. Pressurising the master cylinder and venting did not improve this. The master cylinder has a tapered slot running the full length of the pressure side above the piston. It is almost impossible to remove air from this void. The cylinder was dismantled, a 1.5mm hole was drilled into this void through the wall of the cylinder and c/sk screw fitted. The screw was accessible with cylinder assembled to the car and was very near the back flange. This was used as an additional vent - Superb clutch, never been so good.