Replacement of brake pads on the rear wheels of the car Skoda Octavia A5 This requires a special approach, especially if your car is equipped with an electronic parking brake. Unlike the front mechanisms, you can not simply compress the piston with a strubcin, as this can lead to irreversible damage to the servo motor. The procedure for dismantling the caliper includes not only mechanical actions, but also a mandatory procedure for transferring the brake mechanism to the maintenance mode through a diagnostic scanner or a special sequence of actions with the brake pedal.
Ignoring the rules of operation with the electronic parking brake actuator (EPB) often causes expensive repairs. Incorrect removal of the caliper can damage the guides, the piston or the electric motor itself, which will lead to the impossibility of fixing the car in the parking lot. To avoid these problems, it is necessary to strictly follow the algorithm of actions, taking into account the design features of the suspension and braking system. Octavia A5It is a version with 1.6 MPI or a more powerful 2.0 TSI.
Preparing the car and necessary tools
Before starting any work on removing the rear caliper, it is necessary to reliably fix the car on a level ground. Use recoil stops under the front wheels and be sure to turn on the first gear or mode P (for automatic transmissions). Raise the back of the car on the lift or use reliable stands, as working under the car on one jack is strictly prohibited for safety reasons.
You will need a specialized toolkit that is different from the standard car kit. The main tool for working with the piston is a special adapter nozzle for compressing the piston, which rotates it when pressed. Conventional rods are not suitable here, since the mechanism requires simultaneous pressing and rotation.
- ๐ A set of heads and rattles (usually need heads on the
13,15and17mm) - ๐ง Special nozzle for compression of the piston of the back caliper
- ๐ Syringe for pumping brake fluid out of the tank
- ๐งผ Brake cleaner and lubricant for guides
- ๐ Diagnostic scanner with function support
EPB Service Mode
Pay special attention to the condition of the brake hose. If you plan to completely remove the caliper, check the hose for cracks and scuffs. Old hoses may not withstand pressure during subsequent pumping or simply burst when bending strongly, which will lead to leakage. brake fluid.
โ ๏ธ Warning: Before starting work, be sure to disconnect the battery's negative terminal if you plan to use a diagnostic scanner to avoid short circuits in the electronics system.
Diagnostics and translation into service mode
If your car is equipped with an electronic parking brake, the first stage of work will be the transfer of the rear calipers to service mode. Without this action, the piston will not be able to press without breaking the mechanism. In service mode, the electric motor is disconnected from the control system, and the piston freely moves inside the caliper body.
There are two main ways to activate this mode. The first, most reliable, involves the use of diagnostic equipment, such as: VCDS, Launch or Delphi. After connecting the scanner to the OBDII connector, you must go to the brake control unit (usually). 03-ABS Brakes) and select the function Basic Settings or Special Functionswhere you will find the item Parking Brake Service Mode.
The second method is available only for some modifications and requires strict adherence to the sequence of actions with the brake pedal and the parking brake handle, but it does not guarantee success on all versions. Octavia A5. Therefore, it is highly recommended to use a professional scanner.
- Yes, professional (VCDS/Launch)
- Yes, a simple ELM327.
- No, I'm planning to buy.
- No, I'll do it mechanically.
After activating the mode, you will hear the characteristic sound of the electric motors โ they will draw the pistons inside. This is a signal that the mechanism is unlocked and ready for mechanical dismantling. If there is no sound, check the contacts and repeat the procedure.
โ ๏ธ Note: If you have not transferred the caliper to service mode and try to disassemble it, you are guaranteed to break the electric motor drive, the replacement of which will cost a significant amount.
Process of dismantling the caliper
After the system is transferred to service mode, you can proceed to the physical removal of the caliper. Start by removing the protective caps from the guide fingers. Unscrew the lower guiding finger using the head of the appropriate size. The upper finger also needs to be loosened, but it is not necessary to twist it completely until the caliper does not fall on the hose.
Remove the caliper from the brake disc, carefully pulling it up. Try not to damage the brake hose, as it can be boiling or have a small range. If the hose prevents complete removal, you can unscrew it from the caliper, but then you will need subsequent pumping of the brakes.
- ๐ซ Do not hang the caliper on the brake hose - this can damage it and depressurize the system.
- โ Hang the removed caliper on a wire or hook so that it does not hang out
- ๐งน Clean the staples and disc seats of dirt and rust
If on your Skoda Octavia A5 installed version without an electronic handbrake, the process is simpler: you just need to unscrew two guiding fingers and remove the caliper. However, even in this case, it is important to be careful when working with a piston, so as not to damage the anther.
โ๏ธ Removing the caliper
Work with piston and replace pads
The most important thing is to prepare a new piston or clean the old one. If you just change the pads, the piston needs to be pulled inside the body. To do this, use a special nozzle that is inserted into the slots on the end of the piston. Turn the nozzle clockwise, while simultaneously applying an effort to press the piston into the body.
It is important to ensure that the piston enters smoothly, without distortion. If you feel strong resistance, do not use brute force โ check whether the mechanism is blocked or if the piston is clamped with an anther. If necessary, use lubricant for guides and seals, but only special, compatible with brake fluid.
| Piston type | Design Feature | Compression tool |
|---|---|---|
| Mechanical (without EPB) | Straight piston | Clamp |
| Electronic (EPB) | The screw mechanism inside | Rotating nozzle |
| Combined | Spring and screw | Fixed adapter |
Replacement of brake pads shall be accompanied by checking the condition of the brake disc. If there are deep risks, production or beat on the disk, it must be replaced or drilled. Installing new pads on a worn disc will lead to rapid wear and creak.
Before installing new pads, lubricate their back and edges with a special high-temperature lubricant to avoid vibrations and creaking when braking.
Installation and reassembly
The installation of the caliper is carried out in reverse order. Put the caliper on the brake disc and new pads, making sure they move freely in the guides. Wrap the guiding fingers, having previously cleaned them of the old lubricant and applying a new layer. Tighten your fingers with the recommended moment to avoid them being twisted or jammed.
After mechanical assembly, the system must be put back into operating mode. If you have used the scanner, perform the function Exit Service Mode. The electric motors will work and push the pistons to the point, pressing the pads against the disk. If you did this manually, just press the brake pedal several times to make the pistons fall into place.
What to do if the piston is not retracted?
If the piston is not retracted even with the nozzle, it is possible that the mechanism has jammed due to corrosion or damage to the thread. In this case, it may be necessary to completely replace the caliper or repair it with an analysis of the mechanism. Do not try to drill or break the piston, this will destroy the part.
Check the level of brake fluid in the tank. When replacing the pads, the piston goes deeper, and the liquid can rise above the maximum. If the level is too high, pump out the excess with a syringe so that during the subsequent ride the liquid does not overflow over the edge.
System check and test drive
After assembly, be sure to check the brakes. Press the brake pedal several times with the engine shut down to make sure that it is rigid and there are no failures. Start the engine and make sure that the indicator of the parking brake on the dashboard goes off after removal from the handbrake.
Before leaving for the road, conduct a test braking at a safe area. Pay attention to the absence of extraneous noise, vibrations and steering the car away. If everything is in order, you can continue to operate.
- ๐ Conduct several cycles of braking with different intensity
- ๐ Listen to the brake system, if there are no creaks
- ๐ Make sure the car does not move away from the vehicle when braking sharply.
The key to the successful replacement of the rear pads on the Octavia A5 is the correct use of the service mode of the electronic handbrake, without which further work is impossible.
Common mistakes and how to avoid them
Many car owners make the mistake of trying to compress the piston without removing the lid of the tank with brake fluid. This can lead to overflow of the tank and leakage of liquid that is aggressive to paintwork and plastic. Always monitor your fluid levels before starting work.
Another common mistake is using the wrong lubricant for guides. Conventional lithium lubricant or WD-40 is not suitable, as they break down rubber anthers and cause jamming. Use only specialized synthetic lubricants designed for brake systems.
โ ๏ธ Warning: Never use WD-40 or regular caliper guide finger lubricants, which will cause them to break down and jam the mechanism.
It is also important not to forget about replacing the anther guides. If they are torn, dirt and moisture will get inside and the fingers will jam. This will lead to uneven wear of the pads and overheating of the brakes.
FAQ: Answers to frequently asked questions
Can I remove the caliper without a scanner?
On electronic handbrake (EPB) cars, this is extremely difficult and risky. Some drivers use mechanical methods to remove the piston, but the risk of damage to the mechanism remains high. Better use the scanner.
Do I need to bleed the brakes after replacing the pads?
If you did not unscrew the brake hoses and did not remove the caliper completely from the highway, pumping is not required. It is enough to press the brake pedal several times.
How long does it take to replace rear pads?
A skilled craftsman spends about 40-60 minutes per wheel. It may take 1.5-2 hours for a beginner to find tools and learn the instructions.
What if the EPB error does not disappear after replacement?
It is possible that the shoe wear sensor was damaged or not connected. Also check if the adaptations were correctly reset through the scanner.
Can I use old shoes if they are not already worn?
Yes, if they have no traces of wear, cracks and uneven wear. However, it is recommended to change them on one axle for uniform braking.