The braking system is a critical component of any vehicle, and Skoda Octavia Tour is no exception. Over time, brake fluid loses its performance properties by absorbing moisture from the atmosphere, which leads to a decrease in boiling point and the risk of brake failure. Many owners of this model mistakenly believe that the fluid can be changed rarely, but this misconception can cost their lives.
The replacement procedure requires care and adherence to a certain sequence of actions, especially taking into account the hydraulic features on cars with ABS and ESP. Unlike newer generations, where the โpullingโ procedure through a diagnostic scanner is often used, on Octavia Tour the process can be performed mechanically if you follow the pumping rules.
Why is it necessary to change brake fluid and when to do it?
Brake fluid is hygroscopic, meaning it actively absorbs moisture from the surrounding air through pores in rubber hoses and seals. This leads to the fact that over time the water content in the composition increases and the boiling point decreases. During intense braking, for example, in the mountains or during a sharp maneuver, the fluid can boil, forming vapor locks that make the brake pedal โwobblyโ or completely inoperable.
Manufacturer Skoda recommends replacing every two years regardless of mileage. However, if you operate the car in difficult conditions, such as city traffic jams with constant braking or off-road driving, the interval should be reduced to 1.5 years. Ignoring this requirement leads to corrosion of calipers, working cylinders and anti-lock braking system components.
- ๐ฅ A decrease in the boiling point of the liquid below 180ยฐC requires immediate replacement.
- ๐ ๏ธ The appearance of rust in the expansion tank signals the beginning of corrosion inside the system.
- ๐ Increased brake pedal travel may indicate air in the system or fluid degradation.
โ ๏ธ Attention: Using old fluid for more than 3 years is strictly prohibited, as this can lead to jamming of the caliper pistons due to the aggressive effects of water and decomposition products.
Selecting a suitable liquid and calculating the required volume
For vehicles of the VAG group, which includes Octavia Tour, the standard is DOT 4 fluid. However, not every DOT 4 is suitable for modern systems. The fluid must comply with VAG TL 52166 specification, which guarantees resistance to high temperatures and compatibility with rubber seals. The use of cheap analogues with a low boiling point is unacceptable.
When choosing, pay attention to the presence of the โPlusโ or โSuperโ mark on the label, which means increased corrosion protection characteristics. Brands like Castrol, Trw or original Skoda Genuine are the most preferred options. It is not recommended to mix fluids of different brands or colors, even if they have the same DOT rating.
For a complete replacement in the system Skoda Octavia Tour usually 0.5 to 0.8 liters of liquid is required. This is due to the fact that during the standard pumping procedure, a small volume of old fluid remains in the system, which cannot be removed without specialized equipment. Always buy 1 liter with a reserve so as not to stop while working.
| Liquid type | Boiling point (dry) | Boiling point (wet) | Service life |
|---|---|---|---|
| DOT 4 Standard | 230ยฐC | 155ยฐC | 2 years |
| DOT 4 Plus (VAG Spec) | 260ยฐC | 180ยฐC | 2-3 years |
| DOT 5.1 | 270ยฐC | 180ยฐC | 2 years |
| DOT 5 (Silicone) | 260ยฐC | 180ยฐC | Doesn't fit! |
- Original Skoda
- Branded DOT 4 (Castrol, Motul)
- Cheap Chinese
- I don't know, I haven't watched
Necessary tools and workplace preparation
Before starting work, it is necessary to prepare all the tools so that the process is not interrupted at the most crucial moment. You will need a set of wrenches, usually 8 or 9 mm, for unscrewing the bleeder fittings, as well as a transparent plastic tube with a diameter corresponding to the fitting. You will also need a container to collect waste fluid and rags.
Be sure to prepare a new brake hose or adapter if the old fitting is soured, but in most cases a regular wrench will suffice. Don't forget to wear protective gloves and goggles, as brake fluid is extremely aggressive to paintwork and mucous membranes. If liquid gets on the body paint, it must be washed off immediately with water.
- ๐ง Socket wrenches or 8-9 mm ratchet for bleeder fittings.
- ๐งด A container for draining old fluid with a volume of at least 1 liter.
- ๐งค Protective gloves and glasses to prevent chemical burns.
- ๐งผ A rag and cleaning agent for the plastic around the tank.
โ๏ธ Preparing for replacement
It is better to carry out work on a flat surface, preferably on an inspection pit or lift. If you have access to the VAG-COM diagnostic equipment (VCDS), this will greatly simplify the process of bleeding the ABS system. Otherwise, you will need an assistant who will press the brake pedal at your command.
โ ๏ธ Warning: Work in a well-ventilated area as brake fluid fumes are toxic and may cause dizziness if exposed for long periods of time.
Step-by-step instructions for replacing and bleeding the system
Start by cleaning the expansion tank cap from dirt so that dust particles do not get inside the system when opening. Open the lid and pump out the old fluid from the tank using a syringe or bulb to the minimum level. Do not pour old liquid down the drain; it must be disposed of at specialized chemical collection points.
Pour new fluid into the reservoir, but not to the brim, leaving room for a level. You need to start bleeding from the wheel that is farthest from the master cylinder, usually the rear right wheel. Then move on to rear left, front right and finally front left. This sequence is critical for proper air removal.
Place the transparent tube over the bleeder fitting and lower the other end into a container with a small amount of new fluid. Open the fitting half a turn, ask an assistant to slowly press the brake pedal all the way and lock it. At this time, liquid with air bubbles will flow from the tube. Close the fitting only when the pedal is already pressed to the floor, and only then release the pedal.
Features of pumping with ABS
If you have a diagnostic scan tool, activating the ABS pump allows air to be expelled from the valve body. Without a scanner, air may remain in the ABS valves, causing the pedal to feel soft. In this case, it is recommended to drive the car and brake sharply several times so that the pump activates itself and expels the air, or use a special pressure gauge method.
Repeat the procedure until clear, bubble-free liquid flows out of the tube. Constantly monitor the level in the tank; it should not fall below the minimum, otherwise new air will enter the system. If the level drops, immediately add fresh fluid, but do not allow it to overflow so that it does not spill onto the engine compartment parts.
Use a marker or tape to mark the fittings as you bleed them, as it's easy to forget which wheel is already done, especially if you're working alone.
After bleeding all wheels, tighten all fittings tightly and check the connections for leaks. Add fluid to the reservoir to the โMAXโ level and close the lid tightly. At this point, the mechanical replacement is complete, but to be completely sure, you need to check the operation of the system.
The correct pumping sequence (ZP-ZL-PP-PL) and monitoring the level in the tank are the main conditions for a successful replacement without airing the system.
Features of working with ABS and ESP systems on Octavia Tour
Cars Skoda Octavia Tour are equipped with an anti-lock braking system (ABS) and an exchange rate stability system (ESP), which have a complex hydraulic unit. Inside this block there are valves and a pump that can trap air bubbles. During normal bleeding without turning on the ABS pump, the air may not escape completely.
If after replacement the brake pedal remains soft or falls, this is a sure sign of air in the ABS circuit. In such cases, it is necessary to activate the ABS pump using a diagnostic scanner. The procedure involves cyclically opening and closing valves, which forces air into the common line, from where it can be removed in a standard manner.
- ๐ Using a VAG-COM (VCDS) scanner allows you to activate the โBleed ABS Pumpโ mode.
- ๐ In pumping mode, the pump operates intermittently, producing a characteristic hum.
- โ๏ธ After activating the pump, the procedure for bleeding the wheels must be repeated again.
If you don't have access to diagnostic equipment, you can try the "swing" method. To do this, you need to sharply press the brake pedal several times while driving so that the ABS system works and activates the pump on its own. However, this method is less effective and requires caution on the road.
โ ๏ธ Attention: Do not attempt to bleed the ABS system on a cold engine if using the bleed method. Allow the engine to warm up so that the pump operates stably and does not overheat.
Typical errors and ways to resolve them
One of the most common mistakes is prematurely closing the bleeder valve before the brake pedal has been released. This leads to air being sucked into the system through leaks, and the whole process has to be started all over again. Also, you cannot open the fitting if the pedal is not pressed, as this breaks the pressure in the system.
Another common mistake is using dirty fluid or getting moisture into the new reservoir. Even a drop of water can reduce the performance of a new fluid. Always use liquid from a sealed container and try not to leave the reservoir open for long periods of time. If the liquid in the tank is cloudy or has a dark tint, it means that contaminants have entered the system and the procedure must be repeated.
Sometimes it happens that after replacement the brakes do not work well and the pedal vibrates. This may indicate that there is air remaining in the system or that the brake master cylinder is damaged. In this case, check all connections for leaks and repeat bleeding. If the problem persists, the cuffs or the cylinder itself may need to be replaced.
What to do if the fitting is stuck?
If the fitting does not unscrew, do not use excessive force to avoid stripping the threads. Use a penetrating lubricant (WD-40) and let it sit for 15-20 minutes. If this does not help, gently heat the connection with a hair dryer, but do not overheat the rubber hose.
Frequently asked questions and answers
Owners Skoda Octavia Tour often face questions related to the replacement procedure. Below are the answers to the most popular ones, which will help you avoid mistakes and save time.
Is it possible to mix different brands of brake fluid?
It is not recommended to mix fluids from different manufacturers, even if they have the same DOT rating. Different chemical compositions may react, resulting in sludge or corrosion. If it is not possible to add the original fluid, add the same one that was filled in earlier, but it is best to completely replace the system.
How long does it take to change brake fluid?
If you have an assistant and the necessary tools, the replacement takes from 45 to 60 minutes. If you work alone or use the pumping method without an assistant, the process can take up to 1.5โ2 hours. Having a scanner to bleed the ABS can add another 15-20 minutes.
What should I do if the brake pedal becomes soft after replacement?
A soft pedal most often means there is air left in the system. Try repeating the bleeding procedure, paying special attention to the wheel sequence. If this does not help, you may need to activate the ABS pump through the scan tool or check the master cylinder.
Can I use DOT 5.1 brake fluid instead of DOT 4?
DOT 5.1 fluid is compatible with DOT 4 and has higher performance, so it can be used. However, do not mix DOT 5.1 with DOT 5 silicone fluid, as they are not compatible. For Octavia Tour It is best to use specialized DOT 4 Plus fluid.
How often should you check your brake fluid level?
The brake fluid level should be checked at every oil change or at least every six months. If the level drops faster than usual, it may indicate a leak in the system or worn brake pads, which requires an immediate service visit.
Regularly replacing brake fluid Skoda Octavia Tour is the key to your safety and long service life of the braking system. Do not neglect the manufacturer's recommendations and use only high-quality materials. A correctly performed procedure will ensure reliable braking in any road conditions.