One rotor 5-10 degrees hotter then other side

CODY GILBERY

MEMBER
2011 BUICK LA CROSSE
2.4L
4 CYL
2WD
AUTOMATIC
130,000 MILES

I recently noticed this on accident and recently took the car to local dealer that I bought the car from to inspect it to let me know if it was safe etc. Well they took it for a drive not sure what they all did they told me the brake pads were around 6mm. They also took a temperature device to check both sides and told me what I already knew one side is 5-10 degree warmer and after a little driving got it a little higher to 13 degrees difference. The dealer told me it was fine and they only see it as a problem if it is 50 degrees or more difference what is your opinion.

Also I did my little tests and jacked both sides up and both wheels spin freely even after holding the brake 10 seconds before testing. What is your opinion?

1 Reply

CARADIODOC

MECHANIC
33,871 POSTS

I've been a brake system specialist since the mid 1980's, and in all those years I have never known anyone to measure the brake temperatures. There are two incidents that come to mind where temperature is a concern, but in neither case did we ever measure it. One has to do with a sticking brake due to a blocked flexible hose or debris in a caliper. In that case, the diagnosis was started by simply feeling that one wheel is very hot and the other was cool.

The second problem was caused by the brake rotors being of very slightly different thicknesses after a perfectly fine brake job. The difference in mass caused the two front rotors to heat up at different rates, and that resulted in changing coefficient of friction unequal on both sides. After a half dozen normal stops in quick succession, at the next brake pedal application, the big heavy truck would suddenly have a very hard brake pull to one side. That was never a concern on older trucks, but since the late '1990's it has started to affect trucks of every brand. Here too we never actually measured the temperature. If we did, it would have to be done while out on the test-drive, and is therefore, not practical.

I don't know where the dealer's mechanic came up with the 50 degrees comment. I taught a Brakes Systems class for nine years, and never heard of that. I suspect you don't have anything to worry about. After a day of hitting up the neighborhood rummage sales, your two shoes are likely to be 10 degrees different. Too.