When removing the parking brake drum, thoroughly clean and inspect the drum for the following conditions:
| • | Cracks |
| • | Scores |
| • | Deep grooves |
| • | Out-of-round |
Surface Finish
Clean slight scoring with a fine emery cloth. Heavy or extensive scoring causes excessive brake lining wear. The drum braking surface will need machining in order to remove these scores.
Do not machine the drum if the drum is grooved and the brake linings are slightly worn. Polish the drum braking surface with a fine emery cloth. Eliminating all of the drum grooves and ridges on the lining requires removing too much metal lining material. If the grooves and ridges match, leaving the drums alone is satisfactory service.
Inside Diameter Check
Measure the inside of the brake drum at two or more places around the circumference of the braking surface. Perform the measurements at the same distance in from the edge of the drum.
Taper Check
Measuring the drum for taper involves taking measurements at the inner and the outer edges of the machined surface at two or more places around the drum.
