QuestionHi Don,
Vin#WBADK8305G9700590
I have an off and on problem with the brake pedal in that when I step on it, it goes further down, but not to the floor. This usually happens when I step on the brake gently. The mechanic replaced the rotors, pads and master cylinder and I still have the same problem. When I complained and he drove the car, it didn't occur and he said he doesn't know what's wrong with it. I went to another mechanic who drove my car and the problem happened. He said the abs sensors on the master cylinder need to be replaced. I told him I'm not sure the master cylinder that was installed has abs, but he said 80% of this model car takes abs. I'm concerned because he didn't even bother to look under the hood. Should I be concerned?
Also, is it possible the first mechanic installed the wrong master cylinder - would both abs and non-abs fit in the slot?
Thanks so much for your help!
Annette
AnswerWell we have a conflict of views.First off the master cylinder,although is attached to the brake booster,is independent of the abs unit.The lines from the master go to the abs unit from there it goes to the calipers.If you have sensor problems the the abs light will come on.Some symptoms of sensor failure are the rapid brake pedal movement and noise(growling) on dry conditions.Common problems of failure are also the wheel speed sensor hubs.The grooves in the bearing surface are rusted and unable to be read by the sensors.This "drop" of the pedal at times could be a problem.The pedal should feel soft(easy to push)but stop 3/4 .There should be some reserve.
I have had cars that the driver never really knew how the felt.I drove it and although it did stop the car I felt it didn't stop it well enough.Upon further discovery I found the brake booster wasn't working right and replaced the unit.Now the brakes feel as they should.
Another thought is the car is rather old.As it gets older parts often not looked at are forgotten.Remeber the basics.Rotrs need to be true and not undersized.Fluid should also be clean throughout the system(bleeding the entire system,including slave cylinder)
So in all yes, you should be concerned because you need to stop and no it probably isn't possible to put the wrong cylinder on.
