8
Resurfacing the Brake Drum
A standard drum lathe may be used to machine the drum surface. Do
not exceed the maximum diameter cast into the brake drum. The drum
should be replaced if it must be bored more than the maximum diameter
cast in the brake drum.
Armature surface machining is a difficult process with most drum
lathes and is not recommended. If it resurfaced it should be machined to
a 120 micro inch finish and must have 0.060” above the stud heads. Do
not remove more than 0.030” of material.
Be sure to remove any metallic chips and contamination resulting
from drum machining. Clean drum carefully before reinstalling.
Heavily scored, worn or oversized drums can result in reduced
brake performance or loss of brakes. This could result in
property damage, serious personal injury, or loss of life.
!
WARNING
C. Brake Magnets
This component transfers the 12 volt power into action by engaging
itself to the armature causing the brake to engage with drum surface.
Inspect the magnet for standard or abnormal wear. Generally a magnet
“works” or it is “dead” requiring replacement.
9. SPRINGS / SHACKLES
All suspension components should be visually inspected at least
every 6 months or 6,000 miles. Check for loose fasteners and torque to
proper values.
Improper torque can cause component failure and the axles to
become detached from the frame. This could result in property
damage, serious personal injury, or loss of life.
!
Fastener Torque WARNING
A. Springs
Springs themselves require no maintenance other than inspection for
breakage or cracks. Painting springs and other components retards rust,
improving the appearance of the items.
If spring(s) are broken replace immediately as driving will cause
additional strain on the other springs.