Was in a rear-end collision that since then has affected my braking. I was at a dead stop and was hit by a driver going roughly 30-40mph. Took it to a mechanic and said the master cylinder was the problem. Insurance is refusing to pay for the work. No problems with braking before the accident. Is it common, or possible, that a rear end collision could cause an issue with the master cylinder?
My car has 167000 miles.
My car has an automatic transmission.
To determine if crash forces led to master cylinder failure you would have to determine exactly "what" failed within the master cylinder. If the master cylinder bore is scored or worn, for example, thus causing significant output pressure loss, that would not be crash related but rather is a consequence of long standing wear. Unless the mechanic has already explained exactly how he concluded the master cylinder is faulty, that is explained specific pressure tests that were performed and what the results were, I wouldn’t be too quick to conclude that that is even the problem area in the braking system. To address your other concern, damage to the brake master cylinder due to crash forces of almost all types is implausible and thus undoubtedly unusual. In your circumstance, I would first seek clarification from the mechanic who "tested" the master cylinder. Alternatively, if you want a certified mechanic from YourMechanic to get to the bottom of this, just request a brakes, steering and suspension inspection and the responding certified mechanic will look at what you have in person and assist you with a resolution. If you have further questions or concerns, do not hesitate to re-contact YourMechanic because we want you to make the most of your repair dollars and help you to get the best possible results.
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