Glenn Mott
Junior Member
I am putting new brake drums on my 1930 fordor. What diameter should the rear drums be turned to?
Diameter of brake drum
- Thread starter Glenn Mott
- Start date
Purdy Swoft
Well-known member
Original model A brake drums are eleven inches in diameter
Charlie Stephens
Well-known member
As Purdy said they are 11.000 new. If they are indeed "new" just have the minimum clean up cut and be sure to arc the shoes to match.
Charlie Stephens
Charlie Stephens
Tom Endy
Well-known member
The cast iron brake drums supplied by Randy Gross are .010 under 11 inches. When the new drum is swaged to the old existing hub flange there may be a slight difference in the concentric of the hub and the drum. The drum should always be turned so that the drum and the hub are concentric.
Turning the drum and taking .010 off will not only make it concentric but also bring the diameter of the drum to 11 inches like Henry ordered.
Tom Endy
Turning the drum and taking .010 off will not only make it concentric but also bring the diameter of the drum to 11 inches like Henry ordered.
Tom Endy
MAG
Well-known member
A step we have found to be useful is to take a skim of the mating surface of the hub before swedging. This removes minor irregularities produced when the original drum was installed on the hub.
While you are truing the brake surface, check the diameter of the emergency brake area. They are often undersized and make installation difficult. Check it against the old drum.
While you are truing the brake surface, check the diameter of the emergency brake area. They are often undersized and make installation difficult. Check it against the old drum.