Brake Drum Temprature?

[Chuck in the Burgh]

I wondered if anybody has tried testing the temp on there drums after testing the brakes? Just finished intalling Ted's Floaters & new drums on the front of my '30 coupe. So I've been running it around the block (carefully) w/ only front brakes connected to balance the braking/adjustment of shoes. Well thought I would try my little infrared thermal gun to check the temp on the front drums for drag and comparative temp (brake shoe pressure). As I tweak the adjustment the temps gets close to equal. At 25mph, stopping hard 7 or 8 times on the one block circuit - I get temps about 340 degrees when I get back to the driveway, when I absolutely minimize braking on the same route, the temp range is around 180 degrees.
Has anyone tried checking temp this? Is the 340 range high, normal or ?? for a "hot" drum?
Thanks for any input, shoes were also arced when drums were turned.
Chuck in the Burgh

 

[Rich in Tucson]

Here is what Roger Kauffman, Technical Chairman for MARC, wrote in answer to a brake drum temperature question in Vol. 58 No. 1 (Jan-Feb 2011) Model "A" News:

"Dear Ed:
I have checked brake drum temperature (sic) several times with a digital infrared thermometer. I have found that good working brake drums should attain a heat range of 160 degrees and 180 degrees. Temperatures over 200 degrees lead to brake fade and paint blistering of drums. Anything less than 150 degrees indicates brakes need adjustment or repair and may not be working correctly. Brake drums should be checked after 8-10 consecutive complete stops after reaching 45 M.P.H."

Take it for what you will but his anecdote is consistent with my experience using Ted's floaters after several hundred miles of use.

You need 4 operational brakes to make any realistic comparison to what is advised above; the brakes were never designed to stop a car with just the fronts. You will be able to make side to side adjustments just fine with all four working. I cannot conceive of any method to compare your 2 brake result with the above and would not advise repeating your test - you are fortunate that the wheel bearing grease did not spontaneously combust and perhaps you ought to now consider changing it.....

 

[john in illinois]

I agree with Rich. 340* is way too hot. Did you arc the shoes to fit the drums? This is mandatory with floaters. Are the brakes too tight and dragging? Les Andrews #1 Mechanics Handbook has very good instructions on setting up brakes. For Ted's floaters,reverse the front to rear adjustment.The floaters are very tricky to set up. Make sure the adjustment rods at the top move freely. Sometimes you need to sand or polish these. If they stick the brakes will stay energised and overheat.
I have found 140* to 160* to be max average after hard testing. I do use temperature to fine tune adjustment.

 

[Chuck in the Burgh]

Thanks guys for the input. Shoes were arced to match drums after they were turned. I'll pull the hubs and double check everything and the grease, then hook up the rears. And check it out again.