Spicer 326837 - Manual (Page 8)

06SE01TBC6298 8
Brake Adjustment - Manual Brake Adjuster
NOTE: An assistant is required to make a brake adjustment.
To determine whether Dana Brakes require adjustment, applied
stroke is measured and compared to the maximum value for the air
chamber size in use on the vehicle.
1. Perform “Brake Maintenance Preliminary Steps”
described earlier.
2. With air chamber pushrod fully retracted, measure
distance from face of air chamber to centerline of clevis pin
hole. Refer to Figure 15. If the measurement is not within
ranges shown in Table 1, reposition clevis. Remeasure the
distance and repeat until within range. Record exact
measured distance as dimension “A”.
Table 1
3. Apply and hold an 80 psi brake application, and again
measure from face of air chamber to clevis pin centerline.
Refer to Figure 16. Record distance as dimension “B”.
4. Subtract dimension “A” from “B”. The difference is applied
stroke. Compare applied stroke to maximum value in
Table 2. If applied stroke equals or exceeds maximum
applied stroke shown, adjust brakes. If less than the
maximum, no adjustment is required and you may perform
Brake Operation Check.
Table 2
NOTE: If adjustment is necessary, Dana Brakes are adjusted to
achieve proper free stroke. The difference between free stroke and
applied stroke is merely the method used to move the brake adjuster
from rest. Applied stroke uses an 80 psi brake application; free
stroke is measured using a lever to move the brake adjuster until the
brake shoes contact the drum. If applied stroke exceeded the
maximum and adjustment is necessary, adjust the brakes as
described in steps 5 through 8 below.
!
WARNING: Block all wheels before beginning this
adjustment procedure
Distance: Clevis Pin Hole
Centerline to Air Chamber Face
All brakes (except Mack and
Trailer Axle) 2-5/8” ± 1/16”
(66.7 ± 1.59 mm)
Mack brakes 4-3/8” ± 1/16”
(111.1 ± 1.59 mm)
Trailer Axle brakes 6-1/2” ± 1/8”
(165.1 ± 3.175 mm)
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A
Figure 14
80 - 90 PSI
Air Chamber Size Maximum
Applied
Stroke Desired Free
Stroke
Type 30” Long Stroke
Type 30”
Type 24”
Type 24” (with 2-1/2”
extended stroke)
Type 24 (with 3”
extended stroke) 2.5”
2”
1-3/4”
2”
2.5”
3/8” to 5/8”
(Without Drag)
Type 20” and 16” 1-3/4” 3/8” to 1/2”
Type 12” 1-3/8” 3/8” to 1/2”
B
Measure This
Distance
at 80 psi,
Dimension B
Figure 15