Drum outer diameter: 243,1 mm. Inner Brake Drum Height: 40 mm.

What is the maximum brake drum diameter?

Brake drums have a wear limit which is the maximum inside diameter the brake drum is allowed to be. This number is often cast on the outside of the drum it’s allowed to be 422.1 millimeters or sixteen point six two inches. This is for your standard American trailer brake drum or drive axle drum.

What is the minimum allowable brake drum diameter?

Most drums are cast with enough thickness to allow 0.090″ of wear. In other words, the difference between a drum’s diameter when new and its discard diameter is 0.090,” but that doesn’t mean you can machine a drum right up to the 0.090″ limit.

When should you replace semi brake drums?

According to an Gunite maintenance and installation manual for heavy-duty brake drums by Accuride, if the brake surface diameter exceeds the allowable limits, the drum must be replaced. “The diameter should not exceed . 120 in., over the original diameter,” the company manual notes.

How thick should a brake drum be?

Ideally, your brake pads should be thicker than 6.4 mm (¼ inches) for proper functioning. If it’s thinner than this, consider getting a replacement soon. Most car mechanics also agree that the bare minimum brake pad thickness is 3.2 mm (⅛ inches).

What do the numbers on a brake drum mean?

Get your Fraser Drum Gauge and slide the bar to the desired length, the bar is set in inches and increments of 1/4″ (or 0.250 of an inch), so for example from 15 to 16 on the slide bar, one line between 15 and 16, is 0.250, the next line would be 0.500, and the following would be 0.750 and after that it would be 16.

What does it mean when brakes are cammed over?

Excessive brake drum depth and very thin lining of the brakes will cause the brakes to cam over. Cammed over brakes will cause the brakes to lock up and you won’t be able to move the trailer. When the s-cam cams over, it rotates past the rollers on the brake and wedges the brakes against the drum.