Kilgore Trout said:
Wow! I always though you knew a lot about cars 300bhp/ton... Guess not...
Just because the rear brakes are only 40% of the brake force does not mean that they cannot be pushed to the limit of the braking that they were designed for. Ever heard of a performance envelope? They were pushed to the limit of their PE and failed...
not at all, it was more to just wind Tom up, lol.
As for the brakes them selfs, well that would depend. Unless cracked rear disc's is common on Mustangs (never heard/read it before myself) I would think it very unlikley that it is cracked.
As cracking would be associated with rapid heating and cooling over a short period of time, cracks can appear but it is far more common in cross drilled disc's as the hole introduces a weak spot where the crack will form.
It would be quite likley that any marks on the disc are just that marks, either from the pads or just part of the metal.
If the disc's are getting on a abit and are well used then blueing, glazing and uneven wear are much more likely. If they are already in this condition then there may cause for them to crack.
If there appears to be nothing wrong with the operation of the brakes then I personally wouldn't worry too much. If you do replace them make sure you do the pads as well.
It might be worth lifting the wheel off of the hub and having a closer look at the disc, if it is indeed cracked then it should become obvious. If it is just a mark then try cleaning that area of the disc with a cloth and some vapour degreaser. You may be able to do this with out taking the wheel off the car, depending what style wheels you have.
is this harmful to continue driving?
