H-26. BRAKE DRUM DATA SHEET
When selecting a Webb replacement
drum, the manufacturer's name and
part number is helpful. If this
information is not available, a
replacement drum can be selected by
comparing dimensions. A drawing is
shown at the right, which indicates the
dimensions required to determine the
existence of a replacement drum. If all
of the dimensions shown are not
available, we must have at least
dimensions C, D, E, J, K, and O to
make a selection.
H-27. BRAKE DRUM SERVICE INFORMATION
To achieve maximum life and optimum performance, proper brake maintenance and brake
balance are essential. The following procedures are suggested as a means of obtaining
maximum service and to determine the need for replacement.
Inspection of Brake Drums
When relining brakes, the brake drum should be cleaned and inspected. To be suitable for further
service, the brake drum should pass the following checks:
A. The brake surface should be free of scoring, excessive heat checks, and free of cracks.
B. The brake surface diameter should be within the maximum diameter cast or stamped on the
C. The mounting holes and pilot must be round and true.
D. The mounting surface must be clean and flat.
If any of the above conditions are not met, the brake drum should be replaced.
Turning the Brake Surface
It may be desirable to turn or resurface the braking surface to remove small heat checks or other
surface defects. The following should be noted when turning:
A. When resurfacing a drum, allow at least 0.040 under the maximum diameter for additional
wear. This usually means the drum may be turned a total of 0.080 over the brake surface
diameter of a new brake drum.
New drum diameter
16.580Diameter after re-bore
limit is reached