TheSilverFox

Is there a write up anywhere on how to remove the brake bias valve? Have found a lot of info on the valve, especially from Garrett. Plan is to take it out, gut it and replace.

Any tips on removal without making a mess with brake fluid? Thanks in advance for your help.

Rocket Rob

Its been a few years since I replaced mine but its not hard. Be sure to use flare nut wrenches so you don't round the fittings. And you will have to bleed the system afterward. I don't remember anything tricky or difficult. I was upgrading mine to the turbo version (60 bar).

jimq

I dont remember any fluid coming out when I went to a 60 bar valve

ja78911sc

Make sure you apply pressure on the brake pedal. I use a two by four wedged between the brake pedal and the front seat. This will minimize fluid loss.

The valve is next to the ABS pump in the front truck. Fairly straight forward and easy to access. I helped a friend remove his front TT brakes. His car had the valve removed (common mod with turbo brakes). The PO had a line made vs. gutting the inside of the valve.

We installed a new OE valve because he went back to the standard C2 front brakes.

Vandit

Put lots of paper towels under there to catch the brake fluid, and just have a large amount on hand to soak it up and keep it off the paint.

The line coming into the top is easy to remove. The one from the bottom wasn't, so instead I undid it from the other side of the elbow at the bottom. The challenge is being able to get the right amount of leverage to break the fittings loose.

The bottom line got a bit out of shape in the process, so upon first reinstall, the fitting was a bit wet, but I loosened an really retightened it and it stayed dry. Eventually, I should probably just replace that piece of hardline since it's not an expensive piece.

When you're gutting the valve, make sure you gut it entirely. All the pieces don't just fall out. You need a 19 and 22 wrench to open up the valve.

11mm flare nut wrench for the fittings.

I used a Channel lock wrench to hold the lower elbow while I loosened/tightening the lower fitting. Use the 22mm to hold the valve while loosening the upper fitting.

robt964

Is this valve on the ABS pump the same one you need to gut/remove when upgrading from tiny 2 pot rear calipers to 993 4 pots?

Thanks

boxsey911

Yes but rather than remove or gut it, most replace it with the 55 bar valve that was used on the C4 and late C2 (with 4 pot rears).

robt964

Thanks boxsey - Do you happen to have the part No. ?

boxsey911

Yes it's 964 355 305 10

robt964

Thankyou :-)

Gus

Took mine out, didn't have a lot of fluid loss - think it is better without - but I am running a 993 brake upgrade front and rear -
Also have the 993 master