BENDIX A2LS Manual

Browse online or download pdf Manual for Automobile Parts BENDIX A2LS. BENDIX A2LS 17 pages. Hydraulic drum brakes w/parking

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Bendix

A2LS

WHEEL CYLINDER END

SHOE RETURN SPRING

EXPANDER END SHOE

RETURN SPRING

WHEEL CYLINDER

EXPANDER

FIGURE 1 - A2LS

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AUTOMATIC ADJUSTING TWO LEADING SHOE DRUM BRAKE

DESCRIPTION

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The A2LS

drum brake is a hydraulically operated duo-duplex

brake with an automatic adjustment and parking brake

feature. The A2LS

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drum brake (automatic adjust, two

leading shoes) provides two leading shoes in either direction

of drum rotation and an automatic adjustment of the brake

shoes to compensate for lining wear.

Both the wheel cylinder unit and expander unit have cast

integral brake mounting lugs, each taking the brake torque

load. The wheel cylinder unit contains two single acting

hydraulic cylinders with automatic adjusters. The expander

unit contains a double acting hydraulic cylinder with a park

brake wedge expander. Wheel cylinder and expander units

have either a 1-5/8 inch (41,3mm) or 1-3/4 inch (44,5mm)

diameter bore depending upon vehicle brake requirements.

The units are hydraulically connected together with a bridge

pipe or crossover tube.

Hydraulic Drum Brakes w/Parking

GASKET

DIRT SHIELD

SHOE HOLD-DOWN CLIP (NOT

FITTED TO EARLY BRAKES)

The single web brake shoes are located by slots in the wheel

cylinder tappet head, the expander input tappet/piston and

abutment tappet, and are retained by the shoe return springs.

As with all Bendix automatic adjusting brakes, provision is

made for manual override of the automatic adjuster. This

should only be needed for initial adjustment of the shoes to

a specific drum clearance, or to back off shoes to enable a

lipped drum to be removed.

The brake assembly incorporates an integral backing plate

(dirtshield) to protect the brake from excessive water and

dirt intrusion. The backing plate (dirtshield) contains a steady

post for each brake shoe to insure that lining material is

kept parallel to the drum braking surface. Both brake shoes

are free to slide on their abutment faces against the backing

plate (dirtshield) and are therefore able to centralize

themselves to the drum. Lining material is 3/4 inch (19,11

mm) thick in the center of the shoe tapering to approximately

5/8 inch (15,9 mm) at each end. Lining inspection holes and

CROSS-OVER PIPE

RETAINING SPRING

CROSS-OVER

PIPE

CAP SCREWS

GROMMETS