DSH Brake
(Duo Servo Hydraulic)
Description
The DSH brake is a 12.50" x 2.50" (317.5 mm x 63.5
mm) hydraulic actuated brake. The duo servo design
permits the leading shoe to transfer all of its force
through the adjusting bolt to the trailing shoe. This
increases the braking action, because the force from
both shoes is transmitted into the anchor of the
trailing shoe. The brake has automatic adjustment
and can be supplied with an optional cable operated
lever for parking brake linkage. Figures 2.5 and 2.6.
WARNING
Some brake linings contain asbestos fibers, a
cancer and lung disease hazard. Some brake
linings contain non-asbestos fibers, whose long-
term effects to health are unknown. You must use
caution when you handle both asbestos and non-
asbestos materials.
Disassemble DSH Brake
WARNING
To prevent serious eye injury, always wear safe eye
protection when you perform vehicle maintenance
or service.
WARNING
Block the wheels to prevent the vehicle from
moving. Support the vehicle with safety stands.
Do not work under a vehicle supported only by
jacks. Jacks can slip and fall over. Serious personal
injury can result.
1. Make sure the vehicle is on a level surface.
2. Place blocks under the wheels not being serviced
to keep the vehicle from moving.
Adjust DLH Brake
NOTE: Each brake shoe must be adjusted separately.
1. The DLH brake is adjusted manually by rotating
the adjustment bolt star wheels from the back of
the brake. Figure 2.4.
2. The adjustment wheels are located opposite the
wheel cylinder offset.
3. Adjust one shoe by rotating its star wheel with a
brake adjusting spoon until a small resistance can
be felt when the brake drum is rotated. Then
adjust in the other direction until the brake drum
can rotate freely.
NOTE: The adjusting tool pivots against the dust
shield hole (or against the brake spider if no dust
shield is used) and rotates the star wheel in the
direction opposite to the handle movement. Move
the handle of the adjusting tool toward the axle
housing while the spoon of the tool is engaged in the
star wheel to adjust the shoes closer to the brake
drum. Move the handle away from the axle housing
to adjust the shoes away from the brake drum.
4. Adjust the other shoe after you complete the first
shoe adjustment.
5
Section 2
Hydraulic Brakes
Figure 2.4
Figure 2.5
DSH BRAKE
OFFSET WHEEL
CYLINDER
BRAKE ADJUSTMENT
STAR WHEEL
BACK VIEW
OFFSET WHEEL
CYLINDER
BRAKE ADJUSTMENT
STAR WHEEL
SPLIT DUST SHIELD
