Clutch and Brake Bleeding Techniques

[Dan Cordon]

With all the talk about clutch bleeding, I thought I'd share my 
technique that I use for bleeding systems. I've used this on brakes for 
dozens of cars, and even a few months ago on my audi clutch (after MC 
rebuild).

Below is a link (sorry for the length) to a picture I made of the setup. 
Really, you just need a clear piece of tubing that fits snugly over the 
bleeder valve and a cup of water. You can use non-clear tubing, but it's 
not as cool :o)

1) Press one end of the tubing over the bleeder valve.
2) Place the other end of the tubing hose below the water in the cup
3) Open the bleeder valve
4) Depress (or have friend do it while you watch) clutch/brake pedal a 
few times. Keep reservoir topped off. Continue bleeding until fluid 
coming out hose is clear.
5) Close bleeder valve
6) Repeat for other circuits if necessary.

http://www.its2.uidaho.edu/cordon/dan/images/car_images/brake_bleeding.jpg

The key to making this work is keeping the end of the hose in the fluid. 
By doing this, the cylinder will draw fluid from the reservoir *instead* 
of sucking it up the hose.

NOTE: In this setup, fluid in NOT drawn from the cup. It's just used as 
an means to keep air from drawing back in to the cylinder.

I've done this by myself many times with success, though I prefer to 
have another person operating the pedal. This way I can watch things to 
tell when they've cleared up and close the valve quickly when done.

Also, when doing my clutch circuit, I couldn't get any other method to 
work. This way worked great.

-- 
Dan Cordon
Mechanical Engineer
University of Idaho - Engine Research Facility