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View Full Version : brake vacuum booster pushrod misalignment



malovingood
12-30-2013, 09:10 PM
I recently replaced the brake master cylinder w/vacuum booster on a 1972 El Camino. It has a stock 350 motor. I have a problem with the Deco Moraine Power Brake Booster/MC I purchased from OPGI. It is part # CH25896 11" Booster w/disc Master Cylinder. They purchased it from Classic Performance Parts and said to contact CPP for help.

After installing the replacement brake vacuum booster directly to the firewall, I discovered the brake vacuum booster was tilted up at an extreme angle due to its mounting bracket. This angle resulted in the brake pushrod being out of alignment with the brake pedal. I connected the brake extension rod (or pushrod) but it tilted up at such an extreme angle it was touching the plastic shrould for the brake booster. This has resulted in my brake pedal not completely returning to the off position and I have noticed my battery has been going dead due to the brake light being engaged. After adjusting the brake light, this still occurs. There's no spring holding the brake pedal at rest.

Due to the extreme upward angle of the pushrod, I would think something is extremely out of alignment. The first brake booster I received may have failed due to this extreme angle of alignment. The pushrod has to be pulled up to connect it to the brake pedal. I may have to drill a lower hole in the brake pedal to ensure correct alignment or replace the brake pedal with one that has a lower or multiple alignment holes.

Has any of your other customers had a problem with the alignment of this Delco Moraine brake booster? I'm sure the brake booster is mounted flush with the firewall. I don't know what would cause such extreme misalignment. OPGI stated it was the right one for a 1972 El Camino. I could have the wrong brake pedal but I doubt it. When comparing the old booster with the new one the only difference I could find was that the mounting bracket on the new booster did appear to have a slightly steeper pitch to the mounting bracket.


The original brake booster had no identifying marks other than the top tab was marked with 851. On the side it was marked with "REM FG" and WR D3" below it. I don't know if I have to replace my brake booster a third time or replace the brake pedal and hope for the best. I would appreciate it if you could help me figure this out. It is becoming too costly and taking too much time to solve a seemingly simple problem. The pushrod was pulled up to connect it to the pedal and I feel that may soon cause a vacuum leak or be an unsafe installation.

CPPAaron
01-02-2014, 10:43 AM
When the cars were built they were made with a Power brake position on the pedal due to the pushrod angle. Power boosters like yours will have a hole 1" lower on the pedal arm for this. While converting a manual brake pedal to work with the new or reproduction booster it is required to add this second hole onto the pedal arm.