ricky1329

Seem. It doesn't make sense.

Brake oil contamination ???? You mixed two different brand name before ?

ricky1329

If you have any doubt about them accidentally mixing fluids, take a small sample of the "brake fluid" from the master cylinder (even better to take it from a caliper bleeder) and put it in a clear glass. Add some water, brake fluid is water-soluble and will dissolve completely. If there is any petroleum contamination it will "slick" or float on the top. BTW, most every other fluid (power steering, ATF, and, of course, engine oil) is petroleum-based so that will give you proof that it was contaminated if that was in fact the case. There is only one way that would happen and that is if the wrong fluid was manually put into the master cylinder. Hygroscopic water "contamination" (from age) can affect performance eventually (heat fade, etc.) but will not cause the seal swelling and the repairs they are describing. The simple costs you are describing are exactly what happens when you have oil swelling, ALL rubber, calipers, wheel cylinders, master, combination valve, everything has to be replaced that has ANY rubber. If water "contamination" was the reason, 90 percent of the cars on the road would have that problem. Petroleum contamination will do what you are talking about every time. If you didn't do it, someone else did, that just doesn't "happen". Good luck.

houbmw

Hey buddy, thanks for the reply. Honestly, I haven't touched the brake fluid but I ended up paying for it. The shop said they never touched the master cylinder when they replaced the rotors and brake pads. The dealer claims it was not them...so I have no idea on what to do besides blaming them lol.

houbmw

Also, can you mix different brand brake oils (maybe they topped it off and it got contaminated like that)?

ricky1329

Mix is not a issue but ensure both in same DOT ratings. Brake fluids with different DOT ratings should not be mixed; not all DOT fluid is compatible. This is because it will dilute and reduce the properties of the higher specification DOT fluid, or in the case of mixing of glycol with silicone fluid may cause corrosion due to trapped moisture.