22:11. Back brake support
Prevention
The brake fluid used in hydraulic system of coupling is poisonous therefore at its hit on skin it is necessary to wash out immediately this place a plentiful amount of water. If liquid got into eyes or in an organism, it is necessary to see a doctor immediately. Some liquids have property to ignite easily and can light up even from contact with hot knots of the car. Besides, the liquid used in hydraulic system of coupling dissolves paint and plastic therefore at hit of liquid on a paint and varnish covering of the car wash out it a plentiful amount of water. Also this liquid is hygroscopic, i.e. absorbs moisture from air and therefore the liquid which is stored a long time in open ware is not recommended to be used.
During the work of brake shoes brake dust which contains asbestos, unhealthy forms. Therefore when cleaning brake shoes do not use compressed air and do not inhale dust.
Removal
Prevention
At installation of a back brake support it is necessary to use new bolts of fastening.
| PERFORMANCE ORDER |
| 1. Lift a back part of the car and record on supports. Remove the corresponding back wheel. |
| 2. For reduction of losses of brake fluid uncover a popolnitelny tank of the brake system, close a tank mouth polyethylene and again screw a cover. It is necessary in order that the cover hermetically closed a popolnitelny tank. Alternatively, using a clip, press the brake hose going to a support. |
| 3. Clear area around the connecting coupling of a brake hose and a support. Weaken the connecting coupling fixing a brake hose to a support. |
| 4. Remove brake shoes. |
| 5. Unscrew bolts of fastening of a support, then screw together a support from a brake hose and take it from under the car. |
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Repair of a support
Piston arrangement in a back brake support
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1 – support;
2 – measuring template;
3 – piston;
4 – brake disk
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| PERFORMANCE ORDER |
| 1. Being careful, clear a support of brake dust and dirt. |
| 2. Note an arrangement of pistons in a support in order that they could be established correctly on the places. |
| 3. Take pistons from a support for what it is possible to use air under the low pressure given to the brake cylinder through an opening for a brake hose. At the same time instead of brake shoes establish wooden whetstone. Remove dustproof covers from pistons. |
| 4. Using the small screw-driver, take sealing rings from flutes in support openings. |
| 5. Wash out all details in methyl alcohol or pure brake fluid and wipe them. For a clearing of tubes and openings use compressed air. |
| 6. Check a condition of all details of a support and replace the worn-out or damaged details. |
| 7. Pay special attention to the cylinder and the piston. In the presence of scratches, рисок, wear or pointed corrosion it is necessary to replace the piston and the cylinder, and it means that it is necessary to replace a support assembled. |
| 8. Irrespective of a state, replace all rubber consolidations. |
| 9. At installation check that all details pure and dry and that each piston is installed in the opening. |
| 10. Dip pistons and new sealing rings of pistons into brake fluid and apply a thin film of brake fluid on openings for pistons in a support. |
| 11. Establish sealing rings in support openings. |
| 12. Before installation of the piston in a support turn it in such situation that the ledge on a flange of the piston was from above. For check of correctness of installation of the piston in a support of Mercedes-Benz recommends to use a special template (see the drawing). It arrange ny the piston excludes squeal during the work of brakes. |
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Installation
| PERFORMANCE ORDER |
| 1. Using the corresponding tap, clear openings for bolts of fastening of a support. |
| 2. Screw a support on the coupling of a brake hose. |
| 3. Establish a support into place and fix by bolts, having tightened them the required moment. |
| 4. Tighten the coupling of fastening of a brake hose to a support the required moment. |
| 5. Establish brake shoes and remove air from the hydraulic brake system. If during the work with the hydraulic brake system all precautions were observed, then it is enough to pump over only the corresponding back brake. |
| 6. Establish a wheel, then lower the car on the earth and tighten bolts of fastening of a wheel the required moment. Check the level of brake fluid. |
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