Brake Proportioning Valve

i got them from a hydrolic shop. i dont remember the size. they have to be chemical resistant though


You want EPDM rubber, which you're not going to find at your local parts store. It's fully compatible with automobile brake fluid.

FWIW I'm the guy that provides the tool mentioned above to NPD. I've also got a number of prefab o-rings kits to rebuild the brake valves used on Fords.