Steve W
Nov 24th, 03, 05:50 PM
The previous owner of my car put GM disc brakes on the front just before I bought it. Drums in back. No power booster. But the pedal was so hard, I had to almost use BOTH feet and 3 blocks to stop the car. So, I took it to the Chevy dealer and I had a power booster installed, which led to the MPBrakes vacuum pump (because the cam doesnt let the motor produce enough vacuum). New m/c, propotioning valve, etc. Everything seemed awesome, brake pedal feel was fine, no pulling...good to go. This was a few months ago.
Yesterday I'm driving the car and I'm making mental notes about the next things I'm having done...suspension, sub-frame connectors, motor, etc, and I start thinking about the brakes. I pull off on a side street, get the car up to about 45 mph and just NAIL the brake pedal. No skid...just an almost-abrupt slow-down. Tried it anywhere from 35 to 50 mph...and still, no skid. Acts almost like ABS, but not as fast. No matter what, I couldn't lock up the brakes. It slows OK, but I never tried a "panic stop" before. Now I'm wondering, why can't I lock 'em up? The brake pedal feel is crisp, not spongy and the m/c is full. Any ideas?
Side note: I have noticed that the vacuum pump comes on a lot more often now...if I'm idling with my foot on the brake, in gear, the pump is almost constantly on. Also, when the pump cycles on, the lights dim just a bit for a nano-sec. It wasn't like that before, and it didn't just 'all-of-a-sudden' start doing this, it was very gradual. In fact, I almost didn't mention it. Its almost as if the booster is requiring more vacuum to do the same job, and the pump is requiring more electricity to supply the vacuum.
I'm getting a new vacuum-producing motor (Fastburn 385) in January, so I'm not really concerned with the pump, if thats what causing the problem. But I should be able to nail the brakes and skid...don't you think? Would bleeding help? I still want to drive the car til January.
Yesterday I'm driving the car and I'm making mental notes about the next things I'm having done...suspension, sub-frame connectors, motor, etc, and I start thinking about the brakes. I pull off on a side street, get the car up to about 45 mph and just NAIL the brake pedal. No skid...just an almost-abrupt slow-down. Tried it anywhere from 35 to 50 mph...and still, no skid. Acts almost like ABS, but not as fast. No matter what, I couldn't lock up the brakes. It slows OK, but I never tried a "panic stop" before. Now I'm wondering, why can't I lock 'em up? The brake pedal feel is crisp, not spongy and the m/c is full. Any ideas?
Side note: I have noticed that the vacuum pump comes on a lot more often now...if I'm idling with my foot on the brake, in gear, the pump is almost constantly on. Also, when the pump cycles on, the lights dim just a bit for a nano-sec. It wasn't like that before, and it didn't just 'all-of-a-sudden' start doing this, it was very gradual. In fact, I almost didn't mention it. Its almost as if the booster is requiring more vacuum to do the same job, and the pump is requiring more electricity to supply the vacuum.
I'm getting a new vacuum-producing motor (Fastburn 385) in January, so I'm not really concerned with the pump, if thats what causing the problem. But I should be able to nail the brakes and skid...don't you think? Would bleeding help? I still want to drive the car til January.