Symptoms: Passenger front caliper not braking as hard as driver front caliper. Car pulls left, but not dramatically. It is easy to get the ABS to kick in by braking hard, and the driver side front tire is first to lose traction under hard braking, makes hard gripping and skidding sounds when doing so. Passenger front caliper is very hard to bleed — requires very hard pedal press to get fluid out. Actions taken: Mechanics have replaced pads/rotors. Said system was fine. Since giving up on mechanics, I have rebuilt the right-front caliper, and eventually changed out all calipers with a factory rebuilt, and symptom persists. Replaced all flexible lines when replacing calipers, problem persists. More symptoms: Driver side tire wears faster, passenger side brake pads are wearing more slowly. Problem has persisted for several years, three mechanics have worked on it and have been unable to resolve. (Actually they claim there’s nothing wrong after working on it, but the symptoms are pretty clear.)
Additional info.: Rotors on car now are about two years old. Have tried going back to the stock rotors, then re-replaced with these aftermarket rotors. No noticeable difference. 96K miles on car. As enumerated above, I’ve rebuilt the problem caliper, purchased a rebuilt caliper, same results. I’ve also replaced all the brake lines, but not the hard lines that run throughout the car, just the flexible part. I’ve also flushed the fluid, replaced rotors and pads.
Pulls when braking
I would start by looking for a bent or kinked brake line going to the problem caliper side. This is based on you mentioning that it is hard to bleed on that side. This would indicate a restriction. The brake system is hydraulic and thus should provide the same pressure throughout. You should be able to bleed both sides with ease. In fact you should be able to crack the bleeder and gravity should allow the fluid to come out. Typically when one caliper works and the other does not there is air in the system. If there is a restriction or kinked brake line, this can happen as well. I have seen a similar issue like this once and the cause was from the caliper being put on in a manner that twisted the caliper hose the wrong way. Might check that also.