View Full Version : Drum Temperature

12-16-2019, 05:05 PM
Just wanting to know if others have noted their drum temps when traveling and making several stops. Big 5Rs drum brakes only. Mine seems to be about 50-80F over ambient after a few stops. Just wondering what normal might be. This is the first time I've actually checked the drum temperature. Only tire temp prior which runs about 5-15 over ambient. And since I've been running TPMS w/temp, have not even checked.

12-16-2019, 05:26 PM
When I had drum brakes, in the summertime mine ran anywhere from 80 - 120 degrees above outside temp like after a stop along the interstate coming down the off ramp and then maybe 2-3 more getting into a fuel stop parking lot.

12-16-2019, 07:21 PM
As long as there isn't any flames or smoke, you are probably good. There are way too many variables to give a good number, speed, ambient temperature, weight of trailer, how long you were on the brakes, and probably more. Shortly after we left the Western Region Rally at Coos Bay, OR this past June, a fairly new fifth wheel came blowing by us on the 101. Maybe 20 miles later we caught up with the same rig on the side of the road, smoke billowing out from his brakes. I suspect his excessive speed and the winding road may have contributed to the excess heat in his drums. The safest thing to do is not riding the brakes.

12-16-2019, 09:34 PM
Dot 3 brake fluid has a wet boiling point of apx 400 degrees Fahrenheit. At that point you will start to get brake fade. If you release the brakes and stay off them the temp will go back down and your full braking ability will return. If you are going down a long steep hill and over use your brakes you can reach that point within a few minutes. On a flat curvy road you would have to be really flying to over heat your brakes. On Road race cars you can actually see the discs glowing in the dark because of the heat they develop briefly, however it quickly dissipates when they accelerate and create cooling due to to the high air velocity going over them. All this is to say that 50 to 80 degrees over ambeiant is nothing to be concerned about. One of the advantages of disc brakes is that they shed heat much more rapidly than drums.