Checking the brake pads
The brake pad wear warning light indicates that you need to measure the thickness of the remaining brake pad material. Brake pads should have a service life of approximately 5000 km, i.e. further verification is not performed when the mileage approaches this value. As a rule, a decrease in the lining thickness by 1 mm corresponds to a car mileage of at least 10,000 km, and even then under adverse operating conditions. Under normal conditions, the mileage is much greater, i.e. pads last longer.
For a quick check, which should be carried out regularly, it is necessary to shine a flashlight through the hole in the wheel disc into the brake caliper. For a more detailed inspection, remove the wheel so you can see the block better. With a pad thickness of 7 mm, the wear limit has been reached and the pads need to be changed. During the test, the thickness of the base plate is also measured. Its thickness is 5 mm, i.e. the remaining patch has a thickness of 2.0 mm.
Brake lining thickness is measured between the edge of the metal plate (2) and brake disc (1).
Replacement of brake pads
This work should be done only when there is some skill in working with the brakes. traffic safety depends on it.
Audi models are fitted with two different caliper designs. Both are described in this section. These designs can be identified by the markings on the brake caliper. For ATE brake calipers (Teves) there is a designation "AND THOSE" and the emblem of the company Audi (4 rings). ATE also uses hexagon socket bolts, which are closed with rubber caps.
Attention: Brake pads should only be replaced as a set. Also, never swap the pads from one side to the other in order to even out possible wear. It should be noted that only parts should be used. recommended by manufacturers.
Girling brakes
Pull the cylinder body outwards by hand. This pushes the pistons back in. Before doing this, you need to remove some brake fluid from the brake fluid reservoir, because. fluid may leak out and cause damage. It will definitely happen. when the tank is filled with liquid to the brim. Brake fluid is poisonous! You can not suck it out with your mouth through a hose, you need to use a pear or medical syringe. The liquid must be drained into a special container.
Loosen the bottom hex bolt of the cylinder body (2). To do this, you need to hold the guide pin on the inside with an open-end wrench in order to unscrew the bolt with a box wrench. Unscrew only the bottom bolt, never loosen the top bolt (1). It must be replaced if it loses its reliability.
Swing out the cylinder body (caliper) (2) and take out the brake pads (3 and 4). Remove heat shields from pads (1). Be sure to pay attention to how they are installed in order to arrange them then in the same way.
Clean the guide planes or the area in the housing housing with compressed air, if possible, and if not, with a cloth. Do not use mineral solvents or sharp-edged tools. Check that the protective cap and clamping ring fit correctly. Damaged, brittle or hardened protective caps must be replaced. Before installing the brake pads, check the brake disc. In the presence of deep potholes or scratches, the brake disc must be removed and re-sanded, or replaced.
Install the heat shields in the old position on the pistons (when using new covers, install the same).
Install brake pads. You may need to push the pistons in further. For this there is a special clamp, which is shown in the figure. If it's not there (he goes to service stations), then you can push the pistons with a piece of wood. When doing this, make sure that the brake fluid does not spill out of the reservoir.
Swing the cylinder body down (so that he does not hit the pads) and secure it with new self-locking bolts while holding the guide pins with an open end wrench as described above. The tightening torque is 30 Nm. In this case, it must be borne in mind that the open-end wrench should not be too wide. This may mean that the key will be clamped without reaching the required tightening torque. The cap wrench, of course, must be replaced with a cap head with a torque wrench. New bolts are included with every Audi brake pad replacement kit. These bolts must be replaced in every case. The repair kit also contains two heat shields.
After installation, firmly press the brake pedal several times so that the pads are in their working position relative to the disc.
Check and correct the brake fluid level in the reservoir. It should be remembered that at the beginning of work, the pads should "get used to", so during this period you need to brake carefully.
ATE disc brakes (Teves)
Front brake pad wear is checked in the same way as described above for Girling brakes. If the brake pads are to be reinstalled, they must be marked at their attachment points (inside or outside).
1 brake hose
2 Protective caps for bolts
3 Guide pins, 25 Nm
4 brake pipe
5 Brake caliper cylinder
6 Ribbed bolt, 125 Nm
7 Caliper support
8 Brake pads
9 Mounting spring
10 Bracket for mounting spring
11 Hose clamp
12 Bolt
Remove both front wheels.
Insert screwdriver (2) in the mounting spring (1) and unhook it from the mounting in the brake caliper housing.
Remove the protective caps shown by the arrows from the guide pins to gain access to the bolt heads (fingers).
Remove the brake caliper after loosening the hexagon socket bolts.
Raise the caliper and reinforce with a piece of wire in a suitable place. Do not let the caliper hang on the hose.
Remove the brake pads to the right and left of the brake disc. The inner pad is removed from the piston along with the fastening clamp. The outer pad is removed from the caliper. Sometimes she is strong "sticks". In this case, pry it off with a screwdriver. Clean the guide surfaces or the area in the housing bore, if possible with compressed air or, if not, with a cloth. Do not use mineral solvents or sharp-edged tools. Check that the protective cap and clamping ring fit correctly. Damaged, brittle or hardened protective caps must be replaced. Before installing the brake pads, check the brake disc. In the presence of deep potholes and scratches, you need to remove the brake disc and regrind or replace it.
When installing the brake pads, proceed as follows:
Remove the remaining adhesive foil on the contact surface of the outer shoe.
Push the piston into the hole. Usually, a clamp is used for this, with which the piston is pressed. If the brake fluid reservoir is full, it may overflow. To avoid this, it is necessary to remove the liquid from the tank.
Install brake pads. External brake pads on a metal plate are covered with an adhesive film. It must be removed without a trace. When installing, do not damage the adhesive layer on the metal plate. The inner brake shoe is installed in the piston with the mounting bracket.
Carefully install the brake caliper onto the brake pads and brake disc and screw in the two bolts. Screwed-in hexagon socket screws (use old bolts) tighten in turn until a tightening torque of 25 Nm is reached. This means that you need to have a direct (not curved) hex wrench to use the torque wrench. If the wrench shown in the figure is used, then the tightening torque must be estimated "approximately".
Press the brake pedal several times to bring the brake pads into position relative to the brake disc.
At first, you need to brake carefully so that the pads can "get used to" to disk.
Visitor comments