I have a 1989 328 that I would like to learn more about the brakes. I know the manual says not to coast out of gear since the brakes need the engine vacuum to create boost. I had mine in the driveway and wanted to roll it forward a little, so I released the parking brake. When I went to brake, there were no brakes. When I started the engine, the brakes were fine. Is this due to the brakes not having any vacuum/pressure built up? Is this normal? Also, my ABS light is on again. It did it last year, and we could not find a problem. I had the dealer fill the resevoir to the top (overfilled). When I got home, it spilled some on the driveway, but the light stayed out for 10 months. I tried to overfill it again, but it hasn't helped. All braking is fine. Last year's thread on the ABS light (start from the bottom): http://www.ferrarichat.com/discus/messages/256120/276878.html
Mule, older ABS systems esp. need to "pump up" often times. You might be familar with when you first start your car, and start moving, you hear a pumping sound as you start moving (ABS priming). Perhaps you caught the car in the middle of that cycle?
All modern cars with power assisted brakes require the engine to be running to get the assist. Your brakes should still work, but may require a lot of pressure on the pedal to work.
Isn't there supposed to be a one way valve to stop the booster from bleeding down. That sounds like a BS excuse for the ABS to have to pump up! Pretty scary. David
That's the thing, Dave. It wasn't a loss of power brakes, it was nothing. I had the pedal all the way down and the car did not slow at all (lucky only about 3 MPH). I would think that non-power brakes should still grab some.
They sure should, especially since at 3mph you don't need much stopping power. The pedal s/b rock hard as soon as it engages, but you should have reasonable stopping power as long as you've got a lead foot! By law power brakes have to be fail-safe so that emergency stops can be made even tho the engine and/or power booster has died.
Yes, I can confirm this as we pushed my car down the hill to my house. (It won't start) If the car didn't have brakes, I don't know what we would have done to get in the truck. I still think it relates to the ABS pump not properly pumping and setting pressure.
