Brake Failure

[Howard]

Well, it happened. After bragging about how my Reatta has never ABS problems I guess I'm being punished now. The brakes have failed. The good news was I had warnings thus no harm came to the car, me, or another driver. The bad news, I don't know what the problem is. Several days ago the Yellow and Red brake lights were staying on much longer than usual upon starting. So long it fact that a warning message was flashed on the CRT. Then the lights went off. But the next time I stepped on the brake, the lights came back on. They would stay on a while, then go off. After making it home and raising the hood so I could hear all the brake noises, I noticed that it seem to take a long time for the pump to come on. Once it came on, it would charge the system then cut off. With each push of the brake pedal, the motor would turn on, charge the system and go off. I ordered a new Accumlator and while I was at it, I thought I would replace the two brake relays. A very simple job, just about anyone can do it. Once everything was installed, I turn the key. I heard some clicks just like before, but nothing happened like before. The pump finally turned on and charged the sytem. This time the pedal had to be pressed 8 times before the lights would go on. Good. When the lights came on, the pump would turn on and charge up. This morning, the lights turned off in less than 5 seconds, but backing out of the drive both lights turned on and now the pump will not turn on. I switched the relays around to no avail. My fear is that the pump has failed. How can I force the pump to turn on? I know that if I take the car to the dealership, the first thing they are going to tell me is the whole system is bad and want to charge me thousands of dollars. I want to know for sure that the pump is bad before taking the car into the shop. My hope is that the low pressure switch is bad. Not a cheap part, but much cheaper than a new pump. Speaking of prices. Where is the best place to buy brake parts. The new parts I got from the dealer was about $200. Not cheap, but I wanted them right away. What does a pump cost or low pressure switch and where can I buy them other than from a GM dealer? Thanks for your help Howard

[Barney Eaton]

Sounds like a pressure switch failure.. since you have changed relays and accumulator.<P>You can bypass everything and feed 12v directly to the motor to verify its working.<P>The pressure switch is supposed to turn the motor on at around 1500 psi and off around 2400. You might try just unplugging and replugging the pressure switch connector and see it that helps.

[Guest wally888]

1st. guess would be the Pressure Sensor however I'm about 3 for 10 guessing!<BR> If you go to retta .net/ brakes. give car the tests, you may get some clues. <BR> If the press. sensor is failing to send a signal to run the pump or shuting the pump down too soon......<BR> Someone reported straight wiring the pump to see if it would run or you could check for voltage at the pump terminals(when lights are on, key on)to see if is refusing to run, even w/ voltage.<BR> If you grasp the reasons for the Brake Tests look at test #6. If the Reservoir level does not drop at least 1/2 inch while the system goes from uncharged to fully charged, then the pump is probably not running long enough to fully charge the system. Why not? Probably the Pressure Sensor. Parts prices and sources are also in the Article. Good luck.<BR> If the Buick dealer has the adapter mentioned in the Manual, he can properly diagnose, bout $60.

[Guest]

Mine did somewhat the same but a little different. My tests show that My pressure has been a bit low. Takes a bit to pump up and I only get one pump before the pump has to kick back on. An acumulator puhed it up to 2 pumps. I had replaced the relay and it worked a bit better for a while but today the dreaded lights came back on. Upon opening the hood I found the pump was running but it sounded very different than usual. In fact I could hardly hear it with the motor running. I figured there was a problem when I saw the resovoir level was high. I am thinking My pump is not pumping enough pressure. I have parked it till I get a new one.

[Guest wally888]

Skip, eloborate on, "reservoir level was high?" If you mean just a 1/2 inch or so, where it would be w/o in pressure in the system/reservoir,( to the fill line) I suppose that would be normal if the pump provided no pressure.<BR> If it was at the proper level before the problem and it is above the fill line, where did xtra fluid come from? ( a blocked supply line?)<BR> I find it is difficult to hear the pump w/ the engine running. Just turn the key on and listen.Put your hand on it to check for heat. Mine never gets very warm. A failed Main Relay caused both of my lights to come on.<BR> Just trying to better understand the problem!

[Guest]

Yes Wally the level was about 1/2 inch above the normal triangle. I too have the problem hearing the pump so I ususally shut the engine off to hear it. Then it sounded like it was not pumping anyhting. Just running. It has done that twice since I have gottem it. That was what got Me to start testing Mine.

[Guest wally888]

Skip. Possibly a supply problem? Reservoir filter or line blockage, unless the system is making it's own fluid? Guess a lot of air could have entered system, taking up room.

[Guest]

I kind of figured that it just wasnt pumping out to the system or into the resovoir Wally. I am hoping that the new one solves the problem.