AMMCO 4000E Drum and Disc Brake lathe - Manual (Page 15)

AMMCO Drum & Disc Brake Lathes • 13
Reconditioning Brake
Drums
Preparation
1. Measure the diameter of the brake drum with a
brake drum micrometer.
Figure 16 – Measure drum diameter
2. Determine if the drum will be within maximum
rebore limits after reconditioning.
Note: Most often, the DISCARD diameter is cast into
the brake drum, not the maximum machining diameter.
3. Inspect brake drum. Do not attempt to machine a
drum that is damaged or in poor condition.
Mounting Drums
1. Loosen the boring bar clamp nut and push the bor-
ing bar all the way into the clamp.
2. Mount the drum on the arbor using the proper
adapters, cones, and spacers. Use examples in Figure
18 for guidance.
3. Wrap the drum silencer band snugly around the
drum. Be sure it covers up to the right-hand edge.
Figure 17 – Attach silencer band
4. Position the cross slide by turning the cross feed
handwheel to its maximum clockwise (in) position. Then
back off the cross feed handwheel 2 complete turns .
Figure 18 - Mounting the Drum
Note: Also refer to the Double Chuck Adapter section
(page 10) when mounting drums or rotors using the
Ammco
® double chuck.
Hubbed Brake Drums
A
C
B
L
K
D
F
Tapered cone adapters fit in the bearing seats, making con-
tact near the middle of the bearing race whenever possible
rather than near an edge. Various adapters and spacers may
be used to fill out the shaft of the arbor.
Hubless Brake Drums
A
C
B
E
H
D
F
A cone fits into the center hole of the drum from the inside
to center the drum on the arbor. Select a hubless adapter
which will fit inside the drum, against the flat lug hole sur-
face and either straddle the bolt holes to avoid mounting
against a burr, or remove the burrs. Slip the hubless
adapter onto the arbor followed by a spring, the cone, the
drum, and another hubless adapter. Fill out the shaft with
spacers as needed.
J
I
G
Key to Mounting Adapters, Cones, and Related Parts
A. 1” Arbor G. Spring
B. Arbor Nut H. Inside Floating Adapter (sm.)
C. Self-Aligning Spacer I. Outside Floating Adapter (lg.)
D. Lathe Spindle Nose J. Centering Cone
E. Spacer K. Large Double Taper Adapter
F. Protective Boot L. Small Double Taper Adapter
Note: The self-aligning spacer should always be used next
to the arbor nut when tightening. To avoid overtightening,
wrench tighten the arbor nut counterclockwise until the
drum and adapters begin to turn on the arbor, then continue
to advance the wrench
1 ⁄
16
of a turn. DO NOT overtighten
the arbor nut.
Arrows for reading scale
Dial
Buckle Finger
Silencer Band for Drums