How to keep Drum Brakes cool

When disc brakes first began to appear on racing cars in the early 1950s, there was intense speculation as to whether they would ever be as effective as drum brakes. Drum brakes had been refined until they were pretty efficient binders, even for big-bore road racers, hot rods and stock cars. Today, the brake battle is over, with discs emerging as the easy winner in terms of stopping power, longevity and weight. However, restorers, vintage racers and nostalgia rodders are still getting amazing results with drum brakes, using a mix of period technology and modern materials.

Extreme Heat
Drum brakes have some special problems that must be addressed for performance use. The most significant is heat buildup caused by hot air trapped inside the drum that builds in intensity as braking continues. This may result in one or more possible scenarios, none of them pleasant.


One, the brake linings can disintegrate and break loose from the pads. Two, the drum itself can warp from the heat. And three, the brake fluid can overheat in the wheel cylinders. Any of these can earn you a trip down the escape road or worse!

Performance Tips
The first trick is to let the hot air escape, and help cooler outside air get in. For track-only cars, the backing plates can be liberally drilled with ventilation holes. Just make sure the structural integrity of the backing plate is not compromised, although these are usually made from very rigid steel and can stand some radical ventilating. This approach will work even better if you also add a scoop or duct that directs air from the front of the car to the holes (scoops that attach to the backing plate are still available for the resto rod market).


If the holes are too big you may need to cover them with chicken wire or similar screening to prevent debris thrown up by the wheels from getting inside and jamming the brake mechanism. On the street, these holes present another problem, allowing rainwater to splash inside. Of course, you can always plug up a scoop for rainy weather driving.