Withdrawal
Remove the wheel trim. Loosen the wheel bolts with the vehicle on the ground.
Mark the position of the rims on the front wheel hubs with paint. Thanks to this, the subsequently balanced wheel is set to the same position.
Raise the rear of the car.
Remove rear wheel.
Attention: Changing the block from the inside to the outside and vice versa, as well as from the right wheel to the left and vice versa is not allowed. Swapping can cause uneven braking. It is imperative to replace all front wheel brake pads at the same time, even if only one pad has reached its wear limit. When reinstalling the brake pads, they should be marked when removed.
Unplug connector for wear indicator -arrow- at brake caliper on right wheel, but do not pull on cable.
Using a screwdriver, press off the plastic caps of the fixing bolts -7- and unscrew both fixing bolts with a 7 mm shank wrench.
Pry off the bracket with a screwdriver.
Remove floating caliper.
Remove the outer brake pad.
The inner brake shoe is attached to the piston by a spring -6-. Pull out the brake pad.
Detach wear sensor -7- on right side of inner brake pad.
If the insulation of the contact board is worn, the insulation of the wire is damaged, or the plastic part is worn, replace the wear sensor.
Installation
Attention: when the brake pads are removed, do not press the brake pedal, as this will cause the piston to come out of the housing.
Clean the guide surfaces and the seating of the brake pads in the housing shaft with a suitable soft metal brush or a cloth soaked in alcohol. Do not use substances containing minerals or sharp instruments.
Before installation, check with your fingers that there are no scratches on the brake disc. Scratched discs should be replaced. Before installing new brake pads, clean brake discs with a gray or bluish coating.
Measure the brake disc thickness.
Check the integrity of the piston dust cap -2-. Replace a damaged cap immediately, as penetrating dirt quickly leads to brake caliper leaks. This requires the removal and disassembly of the brake caliper (service station work).
Press out brake piston -2- with squeezing tool. This can also be done with a wooden rod (hammer handle), but at the same time be especially careful that the piston is not tilted and that the dust cap is not damaged.
Attention: When the pistons are depressed, the brake fluid is squeezed out of the brake cylinders into the expansion tank. Monitor the fluid level in the tank, you may need to suck the fluid.
To aspirate the fluid, you can use a vessel used to bleed air from the brake system or any plastic bottle that is intended only for brake fluid. Do not use drink bottles! Brake fluid is poisonous and must never be sucked out by mouth through a hose. Use a suction device After replacing the pads, the brake fluid level must also not exceed the MAX mark, as the fluid expands when the temperature rises. Leaking brake fluid gets on the brake master cylinder, destroys the paint and causes corrosion.
Attention: If the brake pads are heavily worn, check the ease of movement of the piston. In case of heavy movement of the piston, send the caliper for repair (service station work).
Apply a thin layer of lubricant to prevent disc brake squeaks (e.g. Plastitube, Tunap VC 582/S, Chevron SRJ/2, Liqui Moly LM-36 or LM-508-ASC) on the back of the brake pads. In this case, the lubricant is applied only to the back side. Under no circumstances should grease come into contact with the working surface of the brake pad or the brake disc. If necessary, wipe off the grease and clean the surface with alcohol.
Lightly lubricate the brake pad guides in the brake caliper, e.g. Plastitube.
(Drawing W 4426) Insert brake shoe with spring -b- into piston.
(Drawing W 4427) Attach the wear sensor -7- to the inner brake block of the right wheel. Make sure that the retaining clip -8- is in the correct position.
Insert the outer brake shoe -9- into the brake caliper and push the brake caliper onto the brake disc.
Inspect -7- the brake caliper mountings, if necessary, clean the threads of the bolts. The thread in the brake bracket can be cleaned by passing through it with a tap. Bolts with damaged or rusted threads must be replaced. Tighten bolts with a 7 mm open end wrench -8- to a tightening torque of 30 Nm.
Put protective caps on the bolts.
Connect the wear sensor connector on the right side of the vehicle to the connector on the brake caliper.
Insert the caliper into the brake caliper.
Place the wheel in compliance with the marked position of the disk on the hub. Lower vehicle and cross-tighten wheel bolts to 110 Nm.
Install the wheel hub cap.
Caution: With the vehicle stationary, depress the brake pedal several times until a hard resistance appears.
Check the brake fluid level in the expansion tank, top up if necessary up to the MAX mark.
Carefully let the new brake pads run in, for which, by lightly pressing the brake pedal, brake the car several times from a speed of 80 km / h to 40 km / h. Allow the brakes to cool down between successive brakings.
Attention: For the first 200 km, avoid sudden braking until the vehicle comes to a complete stop.