Car rear brake system ล koda Octavia A7 has its own unique design features that distinguish it from many other VAG models. Owners are often faced with the need to replace discs due to increased loads or natural wear, but the process requires specific knowledge and tools. Ignoring disassembly rules can lead to a breakdown of the mechanism, which will cost much more than the consumables themselves.
The main difficulty lies in the fact that the rear caliper Octavia A7 equipped with a piston that is not simply retracted, but rotates when pressed. This is due to the function of the handbrake integrated into the caliper. If you try to simply press the piston without rotating, you are guaranteed to break the threaded mechanism inside, which will require a complete replacement of the caliper or its complex repair.
Symptoms of wear and need for replacement
You can understand that it is time to change the brake discs by a number of characteristic signs that appear while driving or when braking. Drivers often notice a wobbly steering wheel or a vibration in the brake pedal, which indicates disc deformation or uneven wear on the working surface.
In addition to vibration, you should pay attention to extraneous sounds. A creaking, grinding or hum that increases when you press the pedal often indicates that the friction lining of the pads has worn down to metal or deep scratches have appeared on the disc. In such cases, braking efficiency drops critically, and the risk of overheating increases.
- ๐ Vibration in the steering wheel or pedal when braking at speeds above 60 km/h
- ๐ Extraneous metallic sounds (grinding) without pressing the pedal
- โ ๏ธ Increased braking distance and โwobblyโ brake pedal
- ๐ Visual detection of deep grooves or cracks on the disc surface
You should not delay repairs, as damaged discs can damage new brake pads and also lead to jamming of the caliper. Regular diagnostics help you avoid costly consequences and maintain safety on the road.
Tools and preparation for work
To successfully replace rear brake discs with ล koda Octavia A7 you will need a set of specialized tools, since a standard jack and wrenches will not be enough. Pay special attention to the caliper piston release tool, as it is a key element of the process.
You will definitely need a puller or a specialized set for screwing in the pistons, which simulates the operation of a brake caliper. You also cannot do without a torque wrench to properly tighten the mounting bolts to avoid distortions or loosening of the wheels while driving.
- ๐ง Special puller for caliper pistons (VAG or equivalent)
- ๐จ Socket wrench for 17 and 13 (for caliper mounting bolts and guides)
- ๐จ Wheel wrench and reliable jack with stands
- ๐งผ Brake cleaner and wire brush to remove corrosion
Before starting work, the car must be placed on a flat surface and secured with the hand brake on the other wheels. If you change discs on one side, then on the opposite side the handbrake should be lowered so as not to create unnecessary tension in the cable drive.
โ ๏ธ Warning: Never work under a vehicle that is only supported by a jack. Be sure to use safety stands (โgoatsโ) under the sills or body reinforcements to avoid the car falling if the jack is accidentally lowered.
- Special VAG puller
- Regular key
- Pliers
- I buy a service at a service station
The process of removing the old brake disc
Start by removing the wheel rim and brake caliper. Unscrew the two caliper guide bolts with a 13mm wrench, then carefully remove the caliper from the bracket. It is important to hang it on a wire or hook so as not to damage the brake hose from its own weight.
The next step is to remove the caliper bracket. It is secured with two 17mm bolts, which often stick due to dirt and moisture. Use penetrating lubricant ahead of time to make the loosening process easier. After removing the caliper, you will have direct access to the brake disc.
Sometimes the disc may be stuck to the hub due to corrosion. In this case, do not try to knock it down with a mount, as this can damage the hub bearing. It is best to use a plastic hammer and gently tap the disk around the perimeter on the inside so that it moves away from the landing place.
โ๏ธ Dismantling of the brakes
If the disc does not lend itself, you can try to slightly twist the wheeled hub bolt so that it presses on the disk from the inside and squeezes it out. The main thing is to act carefully so as not to damage the thread on the hub.
What to do if the disk is too heavy?
Use penetrating lubricant (WD-40 or analogue) 15-20 minutes before work begins. Try to heat the hub with a construction hairdryer, but do not overheat the bearing. Sometimes helps a sharp blow with a rubber kiangu on the disk through a wooden pad.
Features of working with the caliper piston
This is the most critical stage of working with the back calipers Octavia A7. The piston has an internal thread and requires simultaneous rotation and pressing. If you try to push it with pliers or a regular filmmaker, you break the mechanism.
You need to use a special tool that captures the slots on the end of the piston and rotates it clockwise when pressed. The movement should be smooth, without jerks. Once the piston goes deep, make room for new, thicker pads to install.
- ๐ฉ Use only a quality tool for a VAG group
- ๐ Rotate the piston strictly clockwise (usually)
- ๐ก๏ธ Make sure the piston does not jam during the screwing process.
- ๐งด Lubricate the guide calipers before installation
Once the piston has gone into place, you can move on to installing new components. Make sure the piston is up straight and does not protrude beyond the body. This will ensure that the new pads fit properly to the disc.
The correct technique of screwing a piston is the guarantee that you will not spoil the caliper and save money on its replacement or repair.
Selection of quality spare parts and consumables
When choosing brake discs for ล koda Octavia A7 It is important to focus not only on the price, but also on the type of design. There are ventilated and unventilated discs, as well as options with perforation or notches. For normal operation, ventilated discs of original quality or proven brands are best suited.
A high-quality disc must have a smooth working surface and a sufficient thickness. The packaging always indicates the minimum permissible wear thickness. If you buy perforated discs, make sure they are suitable for your type of braking system, as some modifications have different seating positions.
| Brand | Disk type | Approximate price | Service life |
|---|---|---|---|
| Original VAG | Ventilated | High | 60,000 km. |
| ATE | Ventilated | Average | 45,000 km |
| TRW | Ventilated | Average | 40,000 km |
| Zimmermann | Perforated | High | From 50,000 km |
Do not skimp on the brake system, as this directly affects your safety. Cheap analogues often have uneven material hardness, which leads to rapid wear of the pads and overheating.
โ ๏ธ Note: When buying discs, be sure to check the article against the catalog for your specific engine modification and year of release, as the dimensions may vary even within the same Octavia A7 model.
Installation of new disks and assembly of the node
Before installing a new disc, thoroughly clean the hub of rust and dirt. Use a metal brush and brake cleaner. A clean landing surface ensures that the disc does not beat when the wheel is rotating.
Apply a thin layer of high-temperature lubricant to the hub landing site, but avoid grease hitting the disk's working surface. Install a new disc, fix it with a screw (if provided by the design) and proceed to install caliper brackets and pads.
Install new brake pads in the bracket. Make sure all springs and locks are in their places. Tie the brace to the swivel fist with the force specified in the technical documentation, usually about 30-35 Nm for brace mount bolts.
Before installing a new disc, lightly wipe it with a solvent to remove the conservation oil from the manufacturer.
After assembly, be sure to pump the brake system if you unscrewed the fittings during the work or if the brake pedal became too soft. Push the pedal several times until you feel elastic before starting the movement.
New brakes and final checks
After replacing the discs and pads, proper running is necessary. During the first 200-300 kilometers, avoid extreme braking and extreme loads. This will allow new parts to get lost to each other and ensure maximum braking efficiency.
The first trips are better to make in a calm mode, smoothly pressing the brake pedal. This will help to avoid overheating of new disks, which can lead to their deformation (the effect of the "blue disk").
- ๐ฆ First 100 km avoid emergency braking
- ๐ก๏ธ Watch the temperature of the wheels after the trip
- ๐ Check the level of brake fluid in the tank before leaving
- ๐ Check the nodes for leaks after the first trip
After 500 kilometers, it is recommended to re-check the tightening of the caliper mounting bolts and hub bolts. Vibrations can weaken the fastener, so preventive checks will not be superfluous.
Common mistakes when replacing
Many car owners make the same mistakes when trying to save money on the services of the service station. One of the most common is ignoring cleaning of the calipers guides. If they are rusted, the caliper will not properly press the pads, which will lead to rapid wear and overheating.
Another mistake is using the wrong lubricant. For guide calipers, you can not use ordinary lithium lubricant or graphite, since they destroy rubber anthers. Use only special high-temperature lubricants for brake systems.
Why do new pads squeak?
New shoes can creak in the first kilometers of the run. This is a normal phenomenon associated with laundry. If the creak does not pass, check the presence of anti-script plates and the correct installation of guides.
Also, do not forget to change the caliper mount bolts if they have a disposable design with a tightening deformation. Repeated use of such bolts can lead to their failure during operation.
Using the right lubrication and cleaning the guides is 50% of the success of the long service of the brake assembly.
How do you know if itโs time to change the back brakes?
The main signs are vibration during braking, the appearance of deep furrows on the surface of the disc (more than 1-1.5 mm) and a decrease in braking efficiency. It is also worth measuring the thickness of the disk with a rod and comparing it with the minimum permissible value indicated on the disk itself or in the manual.
Do I need to change both back discs at once?
It is recommended to change the brake discs in pairs on one axle. This will ensure uniform braking and prevent the car from being pulled aside during emergency braking. If you replace only one disk, the load is distributed unevenly.
Can I use perforated wheels on the ล KODA Octavia A7?
Yes, perforated discs are acceptable and even recommended to improve heat and gas removal during heavy driving. However, for a quiet urban drive, conventional ventilated discs can be more practical and cheaper to maintain.
What to do if the caliper piston does not screw in?
Check if you are using the tool correctly. Make sure you rotate the piston clockwise. If the piston does not go, it may be damaged or a mechanism has jammed inside the caliper. In this case, do not make excessive efforts not to break the thread.
How often do you need to change your rear brake pads?
Rear pads on Octavia A7 They last longer than the front, usually between 40,000 and 80,000 kilometers, depending on driving style and operating conditions. Regularly checking the thickness of the friction layer will help avoid unexpected wear.