20.4. Replacement of back brake shoes

 PERFORMANCE ORDER

Minimum admissible thickness of overlays of brake shoes – 1,5 mm.
For assessment of a condition of brake shoes without removal of a drum in a board of a brake there is an observation port.

We take a cap from a board.

For replacement of blocks we install the car on a viewing ditch or the elevator. We remove a back wheel and we weaken a cable of the drive of the parking brake system (see Adjustment and removal of knots of the parking brake system).

Before an otvorachivaniye of bolts of fastening of the brake drum to a flange of a half shaft we tap their heads.

For fastening of the brake drum bolts with the reduced head height are used. Therefore it is better to apply a six-sided tool head at which working sides begin from its end face at once to their otvorachivaniye (if necessary the head can be protortsevat).

Head "on 12" we turn off two bolts of fastening of the brake drum to a half shaft.

For dismantle of a drum the removed bolts can be screwed in two carving openings of a drum (unlike fixing openings carving openings are symmetrized). Bolts at a wraparound will rest against a flange of a half shaft and to shift a drum.

We roll bolts in carving openings.

It is also possible to remove a drum, …

… striking blows with the hammer through wooden whetstone to a drum end face. We strike blows evenly, turning a drum.

We remove a drum.

We show two ways of removal of brake shoes.
At removal in the first way …

… the screw-driver we disconnect the end of the top coupling spring from a block …

… also we take out a spring.

We remove an expansion level.

Passatizhami we turn a shaft of a rack of a forward block before coincidence it with a cut of an external cup.

We remove a spring with external and internal cups.

On the other side of a brake board we take out a rack.

Elements of a basic rack of a block.

We take away a forward block …

… also we remove the lower coupling spring.

We remove a basic rack of a back block.

We take away a back brake shoe …

… also we bring the lever of the manual drive of blocks out of a tip of a back cable of the parking brake.

At removal of brake shoes by the second way it is removed basic racks of both blocks.

We hook a back brake shoe the screw-driver (or we delay it a hand) and we bring its lower emphasis out of a basic plate.

We lower hands brake shoes down, bringing their top emphasis out of cuts of pistons of the wheel cylinder.

We remove the lower coupling spring.

We remove blocks assembled with an expansion level and a spring because of a half shaft flange.

We carry out operation accurately not to damage boots of the wheel cylinder.

We bring the lever of the manual drive of blocks out of a tip of a back cable of the parking brake …

… also we remove brake shoes with an expansion level and the top coupling spring.

Holding on a floor a leg one of blocks, we stretch a spring …

… also we bring an expansion level out of an emphasis.

We remove the top coupling spring.

For removal of the lever of the manual drive of blocks …

… rasshplintovyvay its axis.

We remove a washer, …

… lever …

… also we take out an axis.

Assembly and installation of blocks is carried out in the return sequence (depending on a way of dismantling). At the second way before installation of the second brake shoe we fix the first from movements, having established a basic rack.
At installation of new blocks it is necessary to press pistons in the wheel cylinder. This operation can be executed as follows:

accurately striking blows with the hammer to the piston through wooden whetstone …

… or having established blocks, we press on them, leaning two assembly shovels in a fillet of a brake board. At the same time the top emphasis of blocks presses pistons in the cylinder.

After installation of new brake shoes it is necessary to adjust the parking brake system (see Adjustment and removal of knots of the parking brake system).