All of a sudden had pretty much no brakes and master cylinder looked like it was leaking. When I pumped the brakes with the lid off brake fluid shot up out of the front reservoir. Figured I had a bad master cylinder so got a new one, bench bled it and put it in. Same spurting out of the front reservoir with the lid off. Bled all brakes with vacuum pump twice but they still did not seem right. Bled brakes the old school way, back brakes bled fine but got very little fluid out of the front ones. Maybe the proportioning valve is bad somehow and not allowing fluid to the front brakes? Anyone have this problem before?
It's normal for the fluid to shot out with the lid off. Could be the proportioning valve needs to be centered or maybe bad front hoses???
Yes, A '70 does, but there was NO MENTION of a '70 disc brake set-up. Only what's listed on his I.D. Also, wasn't mentioned if using drum/drum or disc/drum. If either one of the two cars listed had drums to begin with they DID NOT have proportioning valves.
Been there. When I swapped front drums for discs on my 71 Skylark. Was the front of the reservoir completely empty? If so, the prop valve is indeed positioned all the way forward. Close the front bleeders, open the rears, then pump the brake pedal to build pressure in the front. You'll feel the prop valve center after a few pumps. Close everything up, then bleed as you normally do.
Thanks Brian! Followed your advice, got fluid out of the fronts, bled all around, got a better pedal and good stopping power. I reconnected the brake light wire which had broken off years ago and the brake light is on so I may try the procedure again.
