Chrysler RAM TRUCK 2500 1994 Service Manual page 228

BRAKE SUPPORT PLATE INSTALLATION
(1) Apply thin bead of Mopar silicone sealer
around wheel cylinder mounting surface. Then trans­
fer wheel cylinder to new support plate.
(2) Apply thin bead of Mopar silicone sealer
around axle mounting surface of support plate.
(3) Install support plate on axle flange. Tighten at­
taching bolts to 47-68 N-m (35-50 ft. lbs.).
(4) Install parking brake cable i n support plate.
(5) Install axle shaft and retainer.
(6) On models with full float axle, install bearing
hub and axle shaft.
(7) Start brakeline i n wheel cylinder and install
cylinder on support plate. Tighten brakeline fitting
after cylinder installation.
(8) Connect parking brake cable to lever on second­
ary shoe and install brakeshoes on support plate.
(9) Adjust brakeshoes to drum with brake gauge.
(10) Install brake drums.
(11) Fill and bleed brake system.
(12) Install wheel and tire assemblies and lower
vehicle.
BRAKE DRUM SERVICE
BRAKE DRUM REFINISHING
The brake drums can be resurfaced on a drum
lathe when necessary. Initial machining cuts should
be no more than 0.12 mm (0.005 in.) as heavier feed
rates can produce taper and surface variation. Final
finish cuts of 0.025 mm (0.001 in.) are recommended
and will generally provide the best surface finish.
Be sure the drum is securely mounted i n the lathe
before machining operations. A damper strap should
always be used around the drum to reduce vibration
and avoid chatter marks.
BRAKE DRUM REFINISH L I M I T S
The maximum allowable diameter of the drum
braking surface is stamped or cast into the drum
outer edge (Fig. 19). Generally, a drum can be ma­
chined to a maximum of 1.5 mm (0.060 in.) oversize.
Always replace the drum i f machining would cause
drum diameter to exceed indicated size limit.
BRAKE
DRUM RUNOUT
Measure drum diameter and runout with an accu­
rate gauge. The most accurate method of measure­
ment involves mounting the drum i n a brake lathe
and checking variation and runout with a dial indi­
cator.
Fig. 19 Typical Location Of Drum Maximum
Diameter
Variations i n drum diameter should not exceed
0.076 mm (0.003 in). Drum runout should not exceed
0.20 mm (0.008 in.) out of round. Refinish the drum
if runout or variation exceed these values. Replace
the drum i f refinishing would cause the drum to ex­
ceed maximum allowable diameter.
WHEEL NUT TI0HTENING
The wheel attaching nuts should be properly tight­
ened to ensure efficient brake operation. Overtighten­
ing the nuts or tightening them i n the wrong
sequence could cause distortion of the brake rotors
and drums.
Impact wrenches are not the best tools for tighten­
ing wheel nuts. A torque wrench should be used for
this purpose at all times.
The correct tightening sequence is important i n
avoiding rotor and drum distortion. The correct se­
quence is i n a diagonal crossing pattern.
Seat the wheel and install the wheel nuts finger
tight. Tighten the nuts i n the sequence to 1/2 re­
quired torque. Then repeat the tightening sequence
to final specified torque.