Disc brakes temperatures
What is average, what is good, what is bad I bought a temp gun, to check tire temps and realized it could also be used to check wheels bearings and brake parts
Forum Discussion
JRscooby wrote:
I can't say what temps to expect but unlike drum shoes, the disc pads rub all the time not just when brakes are applied.
I did a Google check on that very topic because a friend of mine thinks like you do, and I think differently, I think there is suppose to be an air gap
Pads that touch mean friction and drag, they will wear more, wear it faster, and get hotter,
What I found was the statement and drawings, that when brake pressure is removed the bellows style piston cover retracts the piston and disc/rotor "run out" forces the pads away from the surface allowing for an air gap between pad and rotor, no value was given for the size of the gap
They do not touch when wheels are turning aka driving down the road
Think about this
A tire with a 4ft circumference will spin 1300 times in one mile, if you are driving 60mph that tire is spinning at 1300 rpm , if a brake pad is touching the disc rotor, it and the rotor are going to get hot, that is what friction does, brake pads have lots of friction capability or your vehicle would not stop
