1. Tighten the hand brake, loosen the bolts securing the wheels. Raise the front of the car, put it on stands and remove both front wheels.
2. Clean the area around the bleeder 4 and the fastening of the flexible pipe to the clamp. Unscrew the flexible pipe from the clamp by half a turn and screw it back slightly. Remove the rubber cap from the air extractor. Pour the air extractor with a penetrating agent. It is also important that this product gets inside the air vent opening (photo 8.9).
Attention: This operation is not carried out if during subsequent work it will not be necessary to disconnect the clamp from the elastic conduit.
3. Using a hexagon wrench, unscrew the upper and lower bolts 1 and 9, with socket heads, securing the clamp. Remove the bolts, paying attention to the location of the bushings 2 and 10 (photo 8.10).
4. Pull out the lower part of the clamp first, and then the upper one. Suspend the clamp so that its mass does not bend the flexible conduit.
5. Remove shoes 13 and 16 from the return mechanism, not forgetting that the shoes are different from one another. A block with a larger rubbing surface is attached from the inside.
6. After removing the pads, you can remove the supporting springs (photo 8.13 and 8.14). These springs must be replaced if new pads are fitted. Use a metal brush to clean the dirt from the clamp of the return mechanism and remove the rust plates from the edge of the brake disc from the side of the pad contact plane. For this, a sharp scraper is used. Resting it against the return mechanism, we press the tip of the scraper against the surface of the disk and rotate it towards the tip of the scraper. The surface is leveled with sandpaper. If old pads are installed, it is necessary to remove rust from the mating surface of the pad with the clamp bracket. The pads are replaced in both front wheel brakes. Replacing the pads on one side can cause the car to skid to the side during braking, as the pads will have different rubbing surfaces. Old kolyaks must be installed in their place.
7. Clamp the flexible conduit with a small type wrench "Frenchman" with blunt edges so that brake fluid does not leak out after the clamp is loosened (photo 8.15).
8. Place a flat liquid tank under the clamp and unscrew the clamp from the pipeline. Plug the seat of the flexible conduit in the removed clamp and clean it thoroughly.
9. Then secure the clamp in a vise and unscrew the bleeder using a deep socket hexagon socket wrench. Sometimes a blow with a hammer from above into the air extractor helps. If the air bleeder breaks off during unscrewing, it can be drilled out, which can only be done by an experienced mechanic. Any damage to the thread or cone-shaped sealing surface in the air vent socket is unacceptable.
When reaming the air bleeder, use its inner hole for drilling. At the same time, it is necessary to control the depth of the drilled hole. so as not to damage the sealed surface. If, nevertheless, part of the thread has been damaged, it is necessary to replace the clamp or ream the hole and cut a new thread completely and with a larger diameter. A ball bearing of the appropriate diameter is inserted into the hole and pressed against the socket cone with a conventional bolt. After such repair, it is necessary to check the tightness of the connection.
After unscrewing and extracting the air extractor, it is necessary to remove the rubber casing from the piston (photo 8.16).
10. Grab the piston with tongs by the upper edge and, turning it to the sides, remove it from the hole. If the piston does not come out, then the only way out is to screw back the elastic pipe, turn on the air bleeder and try to push the piston out while pumping the brake pedals.
Attention: Do not take the piston with tongs by the polished surface.
11. Remove the piston gasket from the socket inside the hole, lifting it with a screwdriver (photo 8.17).
12. Rinse the plunger and clamp barrel with alcohol and check their surfaces. If there are slight signs of wear or corrosion, these can be sanded down with 500 or 600 grit sandpaper. In case of severe damage, the piston and clamp must be replaced.
13. If the elements are in good condition, it is enough to replace the gasket set. Before installing the piston gasket in the groove in the cylinder bore, it must be dipped in brake fluid so that it lies evenly in the groove and is not damaged during the installation of the piston.
14. It is necessary to put on a new rubber casing on the piston (photos 8.18 and 8.19). Coat it with a thin layer of silicone grease and carefully press it into the hole in the clamp (photo 8.23).
Insert the outer cuff of the rubber casing into the socket of the clamp body. Screw in the air bleeder.
15. Check if the end of the flexible conduit is clean, then remove the plug from the clamp and screw it onto the conduit, but do not tighten it.
16. Install support springs and pads.
17. Install the clamp on the bracket, placing the top of the clamp first and turning downwards. Install the upper bolt first, then the lower one and tighten to 40 Nm.
Attention: During installation and compression, do not press hard on the clamp so as not to bend the pad support springs. Bent springs cause noise when braking.
18. Press the elastic conduit connection so that it is not twisted or rubbed against other elements.
19. Unscrew the clamping wrench from the flexible pipe and bleed the air from the brake system.
13. It is usually enough to remove the air near the wheel where the clip was removed.
Attention: If only inspection or replacement of brake pads is carried out, it is necessary to extend the piston several times, pumping the brake pedal, and press, for example, with a hammer handle into the clamp. During this operation, the clip must rest against the back of the return mechanism, and not against the brake disc. To do this, we push the piston all the way, then it is given the opportunity to push it 15 mm to another person who presses the brake pedal, and push it back.
If the stroke is greater than 15mm, the piston may fall out of the clamp and it will be necessary to bleed the brakes. When a very large force is used to push the piston in, the piston should be rotated around its axis, grasping the top edge with tongs. Be careful not to damage the rubber cover. Then, using a flat bar with a long bolt, the piston is pressed in as far as it will go (photo 8.21).
After installing the brake clamp, it is necessary to bleed the air from the brake system each time. If only the brake pads are replaced, the brake pedal must be depressed several times to advance the pads to the disc by the appropriate distance. If this operation has not been performed, then at the first braking, the brake will not work, since the pads are moved apart. You must always remember this. Check if there is too much resistance in the system after installing the brake clamp and bleeding while the brake disc is rotating.
These clamps were used in older VW models. The gti versions are equipped with upgraded Girling type brake calipers with ventilated brake disc and anti-lock ABS (pic. 8.8).
Pic. 8.8. Front brake clamp type Girlihg
1 - brake pads; 2 - guide sleeve; 3 - bolt; 4 - rubber casing; 5 - bolt; 6 - bolt; 7 - ABS sensor; 8 - return mechanism; 9 - bolt; 10 - casing of the brake disc; 11 - holder of the return mechanism; 12 - spring; 13 - brake clamp.
Pic. 8.6. Texes Type Brake Clamp
1 - fixing pegs; 2 - screw securing the disc to the hub; 3 - spring ring; 4 - rubber casing; 5 - piston; 6 - piston gasket; 7 - clamp cylinder; 8 - latch; 9 - latch; 10 - air remover; 11 - air gel removal cap; 12 - brake shoe; 13 - repulsive spring; 14 - brake shoe; 15 - clamp frame; 16 - latch of fixing pegs; 18 - brake disc.
Pic. 8.7. girling type brake clamp
1 - protection; 2 - fixing latch; 3 - fixing bolt; 4 - clamp frame; 5 - fixing tin plate; 6 - fixing forks; 7 - spring ring; 8 - rubber casing; 9 - piston 10 - clamp cylinder; 11 - piston; 12 - rubber casing; 13 - spring ring; 14 - support; 15 - air remover; 16 - rubber casing of the air extractor; 17 - brake pads.
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