jnsluft

On my Cab, while installing new brakes, I found a leak in the rear of the car, inside the passenger side tire. I see this machined metal box with two brake lines going into and out of it. It also has a spring going back to the rear axle.

This is the brake pressure control valve, and it drips fluid.

I contacted my local dealer and they said there is only one in North America, in Toronto Canada.

What can I do to repair, replace, or remove it?

Rusty Spokes

Looks like that pressure control valve part number 893614151A is unique to our Cabriolets and may be a few dollars cheaper from VW.




On this website they talk about replacing an "O" ring in there. A simpler design on the Audi 5000..but same principal. SJM Autotechnik, Audi Technical Service Repair Information

jnsluft

Sweet. That looks like the answer. I'm taking mine apart. I'll keep you posted as to what I find. Thank you.

jnsluft

I can't believe I found one on EBay. Brand new. $72 shipped. I'll do the swap and verify that there is an o-ring in my original leaking one, and that it can be replaced.

Rusty Spokes

Good find..take pictures of the old one!

hubturn

Actually, that is the brake proportioner valve. It regulates how the pressure is applied - as in the rears come on fractionally sooner or with more pressure than the fronts so that you don't swap ends on an icy road when you apply the brakes. I wish you the greatest of luck in not stripping out those hose end fittings, because new brake lines will be a royal pain. I had to cut my proportioner valve body to split it just enough to relieve the pressure on the fittings so that they would turn. It was no fun.

Rusty Spokes

I always thought it was interesting Audi used that rear brake proportioning valve and ABS too. Might be some cars sold in Europe did not ABS and the production assembly line just installed them on all cars? A bit of safety redundancy in case the ABS fails maybe too.