11.6. Replacement of boots of drum brake mechanisms of back wheels
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Along with replacement of brake boots also replacement of their coupling and directing springs which as a result of constant cyclic mechanical and thermal loadings stretch/sink over time has to be made, stopping developing the required effort that conducts to a prikhvatyvaniye of brakes and acceleration of wear of drums.
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Components of the drum brake mechanism of a back wheel
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1. Weaken nuts of fastening of back wheels. A car back also establish to Poddomkratta it on props. Prop up forward wheels antiretractable boots. Remove back wheels and release the parking brake.
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2a. The design of the drum brake mechanism is given on an illustration above. Remove the brake drum from a nave. The drum has to be removed rather freely, in case of difficulties, accurately tap it the hammer with soft brisk, or screw in carving openings couple of bolts of M8 (see an accompanying illustration).
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3. It is simpler to make replacement of boots after removal from a pin of an axis of stupichny assembly (uncover the wheel bearing, give a shpindelny nut and remove a washer (see the Head Podvesk and steering).
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4a. Working according to the instructions stated further make check of a condition of components and replace brake boots. Act strictly in the stipulated order. Remember that all four boots of both brake mechanisms have to be replaced at the same time. |
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4b. Before starting dismantle of components, wash out them a special cleaner, then dry (DO NOT BLOW OFF BRAKE DUST COMPRESSED AIR AT ALL!). |
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4 pages. The screw-driver wring out the directing spring down, then develop an anchor finger the lock parallel to a groove in a spring – the last at the same time has to jump aside from a boot. |
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4d. Remove shoe assembly from a brake board (the nave is for descriptive reasons removed). |
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4e. Disconnect a coupling spring.
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4f. Delay a spring on a cable of the drive of the parking brake so that there was an opportunity to grasp a bokorezama cable, holding a spring in the compressed state (try not to cut a torso); now disconnect a cable tip from the executive lever of the parking brake.
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4g. Turn the executive lever of the parking brake, taking away it from a back brake boot – at the same time the fork of an adjusting bolt of a razzhimny level has to be released from the landing flute in a boot what to allow to separate boots. |
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4h. Remove the lever and a spring of the automatic regulator from a forward brake boot.
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4i. Remove a clamp and disconnect the executive lever of the parking brake from a back boot (do not lose the bent washer established under a lock ring).
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4j. Connect a new back boot to the lever (do not forget to enclose a bent washer under a clamp); nippers squeeze the ends of a clamp together. |
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4k. Clean an adjusting bolt and forks of a razzhimny level, then grease them with refractory lubricant. |
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4l. Hook on a spring of the automatic regulator for an opening in a new forward boot, then fill a lever finger in other special opening in a boot. |
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4m. Fill a short fork of a razzhimny level in the groove in a forward boot (track correctness of input of a fork in gearing with the lever of the automatic regulator. |
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4n. Connect the top coupling spring to both brake boots, part the lower ends of boots and fill a fork of a razzhimny level in a groove in a back boot (track correctness of an arrangement of a step ledge of a fork). |
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4 lakes. Grease the surfaces of a brake board contacting to boots with refractory lubricant.
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4P. Bokorezami squeeze a spring of a driving cable of the parking brake (do not cut a cable) and, holding it in such situation, connect a cable tip to the executive lever. |
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4q. Establish shoe assembly on a board of the brake mechanism, having put the top ends of boots in grooves in pistons of the wheel cylinder; connect the lower coupling spring to boots. |
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4r. Pass anchor fingers throughout openings in a brake board and boots, establish the directing springs; develop fingers, having recorded springs; track that the spring of a cable of the drive of the parking brake and the lower coupling spring were got under levels of an anchor bracket as it is shown in a picture. |
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5. Before installation of the reel it is necessary to check it for existence of zadir, furrows, traces of an overheat and other defects. At identification of serious damages which traces cannot be eliminated by processing of a drum with a fine-grained emery paper the drum should be given to a pro-point (with observance of the maximum admissible repair diameter). If the pro-point of a drum cannot be made without violation of requirements to the maximum admissible internal diameter (it is beaten out on a drum – see an accompanying illustration), it is necessary to make its replacement. If it is not possible to make a pro-point of drums, at least carefully smooth out them working surfaces a fine-grained emery paper. |
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Authors of the present manual recommend to make a pro-point of drums regardless of their state for the purpose of any removal of defects and elimination of ovality. |
6. Establish into place assembly of a nave with the wheel bearing, put on a washer and screw a new shpindelny nut, having tightened it with the required effort (see Specifications to the Head Podvesk and steering).
7. Establish into place a wheel, then lower the car on the earth and tighten wheel nuts with the required effort (see Specifications to the Head Routine maintenance).
8. Several times slow down the car at the movement it both to lobbies, and a backing for the purpose of carrying out automatic adjustment of brake mechanisms.
9. Before starting operation of the car, make sure of serviceability of functioning of brakes. |
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