You can save a lot of money by replacing your brake discs yourself, because a garage often charges a lot of money for this. With this article at hand, your car will soon be braking as usual, and you will not pay more than the material costs.
Part 1 of 3: Making the brake pads accessible
Step 1. Buy the correct brake pads
Brake pads can be purchased from an auto parts store or garage. On the basis of the brand, model and year of manufacture, it is possible to find out which brake pads are suitable. There are often brake pads for sale in different price ranges. In general you can say that more expensive brake pads last longer.
Very expensive brake pads are usually intended for the rally and only work well in combination with the right brake discs. Due to the high metal content of these brake pads, normal discs will wear out faster. On the other hand, many people say that cheap brake pads make more noise
Step 2. Wait for your car to cool down
If you've just ridden, the pads, discs, and calipers are likely to be very hot. Wait for these parts to cool before continuing.
Step 3. Loosen the wheel bolts
Use the cross wrench that came with the car to loosen the nuts on the wheel bolts, do not loosen them more than two thirds.
Do not loosen all wheels. Usually you only replace the front or rear brake pads, depending on your car and the wear of the brakes. So start at the front or the back
Step 4. Jack up the car until the wheels can be removed properly
Check in the user manual where to place the jack. Put some blocks behind the other wheels to prevent the car from rolling forward or backward.
Place car mounts under the car frame. Never rely solely on the jack. Repeat the process on the other side of the car so that both sides are securely supported
Step 5. Remove the wheels
If the car is supported by supports, you can completely unscrew the nuts from the wheels. Pull the wheel towards you to remove it.
If you have alloy wheels, you can clean the different parts with a wire brush: the bolts, the holes, the surface to which the disc is attached and the back of the rim. Lubricate with copper grease before replacing the wheel
Step 6. Remove the bolts from the brake calipers with the correct size ring spanner or wrench
The caliper fits like a caliper around the brake disc, the caliper brakes the wheel before the pads are pressed onto the disc, hydraulic pressure is applied to create friction with the discs. A caliper can consist of two halves, but sometimes it is one whole, calipers are secured with two, three or four bolts. Spray the bolts with WD-40 before removing them to make it easier.
- Check the pressure of the brake calipers. The caliper should be able to move back and forth slightly when the engine is not running. If you can't, the caliper is under pressure and could come off when you remove the bolts. To be on the safe side, make sure your body is not in the path, even if there is movement in the caliper.
- Check for shims between the caliper bolts and the caliper surface. These are intended to reduce the squeaking brake noise. Remove them if they are present and keep them well for later re-installation. You will need to replace the caliper without the pads to measure the distance between the caliper surface and the pad in order to put them back properly.
- Many Japanese cars use a two-piece brake caliper, which only requires the removal of bolts at the front. You don't have to remove the entire brake caliper.
Step 7. Carefully hang the brake caliper on the wheel arch with a piece of iron wire
Because the caliper is still connected to the brake hose, it is best to hang the caliper with a piece of iron wire, otherwise there will be pressure on the flexible brake hose.
Part 2 of 3: Replacing the brake pads
Step 1. Remove the old brake pads
Finally! Look at how the brake pads are mounted. They are usually held in place with metal clips. Remove both brake pads. It may take some force to get them out, so be careful not to damage the caliper or pipe while you're at it.
Step 2. Install the new brake pads
Now you can put some copper grease on the caliper seats and the back of the brake pads. This prevents squeaking brakes. But be careful not to get grease on the inside of the brake pads. If the inside is greasy, the brake will not create enough friction, and therefore will not brake properly. Attach the new blocks in the same way as the old blocks.
Step 3. Check the brake fluid
Check the level of the brake fluid and add if necessary. Replace the reservoir filler cap when you have finished topping up.
Step 4. Install the caliper
Carefully slide the brake caliper back over the brake disc, being careful not to damage anything. Retighten the bolts holding the brake caliper in place.
Step 5. Put the wheel back
Slide the wheel into place and tighten all nuts by hand before lowering the car.
Step 6. Tighten the nuts
When the wheels are back on the ground, you can tighten the nuts with the cross wrench. Do this in a "star pattern". Tighten one nut first, then the opposite nut, and so on until all nuts are tight.
Look in the instruction manual for how tight the nuts must be tightened (in the unit Nm). With an air spinning top you can adjust the tightening torque, so you can be sure that the wheels are tight enough and that they are not over tightened
Step 7. Start the car
Apply the parking brake to the car and apply the brakes 15 to 20 times to get the brake pads in place.
Step 8. Test your new brake pads
Do not drive faster than 8 km/h on a quiet street and brake normally. If the car seems to be braking well, you can repeat the test at 15 km/h. Keep repeating until you are driving about 50 km/h. This allows you to check that the brake pads are installed correctly, and it ensures that the brake pads are properly seated.
Listen if there are any problems. A little squeaking is normal with new pads, but if you hear a grinding noise that sounds like metal on metal, you may have installed the pads the wrong way round. Then stop immediately and solve the problem
Part 3 of 3: Bleeding the brakes
Step 1. Remove the master cylinder cover
Brake fluid slowly becomes contaminated and it absorbs moisture from the air, which can lower the boiling point dangerously. The system must be bled before you can replace brake pads and calipers, but you must also make sure there is enough brake fluid in the system before you start. Check the level and add oil if necessary. Leave the filler cap open while you bleed the system.
The reason you need to add fluid is that you are bleeding the fluid at the calipers--that is, the fluid that's in the lines--and there must be enough oil in the master cylinder
Step 2. Determine the sequence of venting
In most cases, you'll need to bleed the brake furthest from the master cylinder first, so read your owner's manual before doing this. The order is different for every car. If you can't find it, look online or inquire at a garage.
Step 3. Place a small plastic hose on the bleed valve
Cheap aquarium hoses are very suitable for this. Place the other end of the hose in a small bottle or container to collect the liquid. To prevent air from entering the system by gravity, make sure that the bottle or container is above the caliper.
Step 4. Ask someone to press the brake pedal
With the engine off, have someone press the brake pedal over and over until they feel back pressure. Let that person call the moment counter pressure is felt, at that moment you can loosen the nipple a turn. Ask the other person to hold down the brake pedal.
- The liquid will now flow through the hose, into the bottle. When the brake pedal reaches the bottom, you can retighten the nipple.
- Repeat this process until you no longer see any air bubbles in the hose.
Step 5. Check the system again for air bubbles
If pressing the brake pedal produces a gurgling sound in the master cylinder, there is still air in the system. Repeat the venting procedure before continuing.
- When replacing the rear brake pads, you must be careful not to damage the parking brake system.
- If you are replacing front brake pads, it may be a good idea after you remove the wheel to turn the handlebars to allow easier access to the caliper. Make sure that the car mounts do not make contact with the steering system.
- Inspect the brake discs. If they are very shiny or worn, this can cause a squeaking sound. If they have become too thin, they must be replaced.
- Never rely solely on a jack. Always use supports and put something behind the wheels so that the car cannot roll away.
- Grease or WD-40 should never come into contact with the brake pads. In this case, the brakes will not work properly.
- Delete never the brake caliper brake line. Air will enter the pipes and you will be even further from home.