I own a 1982 Pontiac Firebird base model which has recently started leaking oil from its Proportioning Valve. I have looked all over the internet for a replacement, and it turns out GM has discontinued the part. Now im faced with difficult and risky task of attempting to fix it, or turn it over to a repair shop as a last resort. The valve seems to leak out of a small circle with a hole the size of a needle inside which was covered by a rubber gasket. I have no clue what this does, and how to repair it.
First up is that the valve is not leaking oil, it is leaking brake fluid. That is bad. The proportioning valve controls the brake pressure to the rear brakes. Most of the braking is done with the front brakes and without the valve you could lock up the rear brakes on medium to hard stops and the rear end could loose traction, that would be a bad thing on a sharp turn. With that said please replace the valve I have never seen a repair kit for them. Have you looked at to GM for the part? They may also have knowledge on a conversion of the master cylinder with the valve built in.
