Wayne Akister, Strathmore, AB, Canada, 1970 Dodge Charger 440

Hi Rick, I've been reading and enjoying your tech for several years. While I thought myself somewhat capable, I've come across a problem that has me baffled.

> 1970 Charger, blown 440,put together two winters ago. Was a drum/drum PB car, converted to disc/drum. During resti, the following were replaced with new/rebuilt. Master cyl, booster, all lines, calipers, pedal assembly, proportioning valve, rotors, pads, flex lines, etc. Also added a Wilwood prop valve after the stock prop valve.

> Car worked awesome for two weeks, then suddenly seemed that the booster crapped out, (had to two foot the brake pedal to get it stopped). Replaced the booster, lasted two days, did the same thing.

> Parked it for the season, and during the winter, replaced the 8.75 with a new Strange Dana, with rear discs. At the same time, replaced the booster and master cylinder with a MP brakes set up, with the proper combination valve (set up for a 4 wheel disc). Re-plumbed the brake lines properly, vaccuum bled the system from the farthest point first, made sure the master was properly bench bled, etc, and I still hardly have enough brakes to stop the car from a crawl. The lines are hooked up properly, everything I can think of is new or has been checked out thoroughly.

> The only anomaly I have found is that the instructions from MP's combination valve indicate that the inlet from the master for the front brakes is supposed to be 3/16", and the rear 1/4". I have 1/4 supplying both. Is this a problem? It doesn't explain why the car braked properly for the first few weeks.

> Also, today I changed the master cyl to a different (rebuilt) unit, car does the same thing. Tried a vacuum pump hooked to the booster instead of using manifold vacuum, same deal.

> What gives? Am I overlooking something basic? The car has been sitting most of the season already, as I won't drive it until the problem has been determined for sure.

> My fingers are sore from scratching my head on this one.

> Any help on this would be appreciated, as the car is just begging to get out of the shop, and on the street where it belongs........

> Thanks