One thing that is correct is if the brake fluid is contaminated with a petroleum product every part that has rubber that contacts the fluid must be replaced at the same time, and all the steel lines must be flushed and dried, THEN all the new parts can be installed. That is always a very expensive repair and it's much worse on GM vehicles with anti-lock brakes. If any one or more parts are not replaced the contamination will leach out of the rubber and recontaminate the new brake fluid.
One clue you can look for yourself is to remove the cap on the brake fluid reservoir and inspect the rubber bladder seal. If it is blown up and mushy, that is a sign of contamination. If the amount of contaminant in the system is significant the symptoms will show up in less than a week, and often in a few days. As disc brake pads wear, the self-adjusting feature causes the fluid level to drop in the reservoir. That will usually pull that bladder seal down out of the cap. When people check the fluid level, like during oil changes or other routine service, they will typically pop that seal back into the cap. If there is grease on their fingertips, the fluid just became contaminated. Brake system specialists and other experienced mechanics will even wash their hands to remove excess fingerprint grease before working with brake fluid components.
I was recently involved as an impartial observer of a case of contaminated brake fluid that involved a very intelligent and reputable shop owner and my very conscientious former student who learned a lot from me about preventing fluid contamination. The problem you are going to have is proving no one else worked on the vehicle or had the opportunity to introduce the contamination. That can include carelessness at the dealership or sabotage at a quickie oil change place. Your other problem is you noticed a brake pedal problem before you took it in for service. To me that suggests a defective master cylinder or some other problem other than fluid contamination. Most commonly contaminated fluid results in a brake pedal that is hard to push, doesn't move very far, and the brakes will stay applied and self-apply harder as they get hot. It's kind of doubtful, but not unheard of, that you could have driven more than a few dozen miles with contaminated fluid.
The mechanic also needs to consider a failure in the anti-lock brake hydraulic controller. There have been reports years ago on GM trucks with the brake pedal intermittently going to the floor, and in one case the guy sailed through a red light, luckily harmlessly, then the pedal was fine again moments later. I never did learn what the outcome with that one was.
Thursday, August 1st, 2013 AT 11:42 AM