Great Dane 42101401 - Manual (Page 11)

OVERSIZE LINERS
To compensate for material removed when refacing
brake drums, X (1/16" oversize) and XX (1/8" oversize)
liners are furnished by the lining manufacturers. When
oversize liners are used the drums should be machined
in increments of 1/16" (radius increased 1/16").
BRAKE SHOE ROLLER CAM FOLLOWERS
Roller cam followers are available in four sizes, each
having been designed for a specific purpose.
STANDARD SIZE (1.250")
Standard rollers are used when installing standard
lining with standard drums, X lining with 1/16" oversize
drums, or XX lining with 1/8" oversize drums.
If the drums have been refaced and oversize rollers
later installed, the oversize rollers must be removed
and standard rollers installed when the new liners are
installed.
1/8" OVERSIZE (1.375")
Use 1/8” oversize cam followers when you install
standard liners with worn or trued drums that are 1/32"
oversize. Circle grind the liners a few thousandths less
than the drum diameter.
1/4" OVERSIZE (1.500")
Use 1/4” oversize cam followers when X liners have
been installed with 1/16" oversize drums and standard
rollers. The standard rollers should be removed and
1/4" oversize installed before the lining becomes worn
to the point when the brake cam is no longer effective.
1/2" OVERSIZE (1.750")
Use 1/2” oversize cam followers when XX liners and
1/8" oversize drums have been used. The standard
rollers should be removed when the liners become
approximately 50% worn, and 1/2" oversize rollers
should be installed.
CAM PLATE SHIMS
When standard liners are installed with worn or trued
drums, or when X or XX liners have been installed and
are approximately 50% worn, shims or a combination
of shims should be installed under each of the cam
wear plates to permit the cam to be returned to the full
release position. Shims are available in 1/64", 1/32"
and 1/16" thicknesses.
BRAKE DUST SHIELDS
The brake spiders used for mounting the brake shoe
assembly parts also become the mounting for optional
dust shields.
The use of dust shields should be determined by
conditions encountered by the trailer. Operations in
mud, sand, dirt, water, and other forms of foreign
materials should be the governing factors. When these
conditions exist during winter months and maximum
cooling is desirable during summer months, dust
shields are easily installed or removed.
BRAKE ADJUSTERS
AUTOMATIC ADJUSTERS
Several different brands of automatic adjusters are
common. Because adjustment differs, refer to the
maintenance and adjustment information from the
manufacturer.
Some automatic slacks are equipped with an adjust-
ment pawl which eliminates loss of adjustment. This
pawl must be removed prior to backing off on the
adjustment to prevent damage to the splined pawl
and adjusting screw.
WARNING Enlarging the drum diameter may
permit the cam to rotate beyond its maximum
lift when the lining becomes worn. This can
result in sticking cams or cam rollover.
To avoid this condition and to obtain maximum
lining wear, oversize roller cam followers or
wear plate shims (depending on the brake
design) should be installed when the liners
become approximately 50% worn.
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NOTICE: Failure to use dust shields during
months where gravel chips, etc., are used on
roads may allow drums to be scored by these
materials. Dust shields may provide the desired
protection.
NOTICE: Automatic adjusters may seem to be
over-adjusting and may seem to be more
sensitive until brakes are properly burnished.