Changing the brake pads yourself is much cheaper than taking the car to the workshop. With only the cost of materials and following the instructions below, your car will brake perfectly.
Steps
Part 1 of 3: Expose the Brake Pads
Step 1. Buy the right pads
You can find them in auto parts stores or at your trusted dealership. The important thing is that you know the year, make and model of the car to choose the pads according to your budget. Generally, the higher the cost, the longer the duration.
Some types of pads with higher amounts of metal are more suitable for rally cars and for use with racing discs. These are best avoided as they can easily cause premature wear of normal discs. Another aspect is that many find cheap pads louder than those made by well-known brands
Step 2. Make sure the vehicle is cold
If you've been driving recently you may find the pads, calipers and discs extremely hot. Make sure you can touch them smoothly before continuing.
Step 3. Loosen the nuts
Use the cross wrench that comes with the jack to loosen the nuts holding the wheel by about two thirds.
Do not loosen all wheels. Typically, front or rear pads are changed depending on the car and brake wear. So start with the front or rear wheels
Step 4. Jack the car up very carefully
Check your car's manual to see exactly where to place the jack under the car. Also put blocks behind the other wheels to prevent the car from moving forward or backward.
Place jack stands or blocks under the car frame. DON'T just trust the jack. Do the same thing for the other side of the machine, so that both sides are safe
Step 5. Remove the wheels
Finish loosening and removing the nuts when the machine is raised. Pull the wheel towards you to remove it.
If the rims are alloy and attached to the pins then you will need to clean the pins, pin holes, disc mounting surface and rear of the rim with a wire brush and apply an anti-seize product before mounting the wheel again
Step 6. Remove the caliper bolts using an appropriate size Allen key or ring wrench
The caliper attaches to the brake disc like a clamp and serves to slow the wheel down before the pads grip using hydraulic pressure to create friction with the discs. Calipers are generally made in one or two pieces, and with a two to four bolt attachment inside the drive shaft housing, where the wheel attaches. Spray the bolts with a product such as WD-40 or Svitol to aid in removal.
- Check the pressure of the pliers. In a machine at rest the pliers should move slightly. If they don't they may be under pressure and come out, once the bolts are removed. When checking, be very careful to keep your body to the side of the caliper, even if it is not under pressure.
- Check to see if there are any shims or washers fitted between the caliper mounting bolts and the mounting surface. If so, they should be removed, but remember their placement to reassemble them later. You will need to refit the caliper without the pads and measure the distance between the mounting surface and the pad to reassemble them properly.
- Many Japanese machines have two-piece calipers that only require the removal of 12-14mm head bolts. There is no need to remove the entire caliper.
Step 7. Hang the clamp under the fender very carefully
The caliper will still be attached to the brake hose, so hang it up with a wire or something else, so it doesn't hang and put no pressure on the brake hose.
Part 2 of 3: Change the pads
Step 1. Remove the old pads
Pay attention to how each pad is attached - they typically snap into or snap into metal clamps. Remove the old pads. You may need to force a little to remove them, so be careful not to damage the caliper or tube.
Check that the brake discs are not damaged, otherwise replace them. Changing them is always recommended during the pad replacement process
Step 2. Put on the new pads
At this point you can put the anti-seize on the metal parts and on the back of the pads. This way the brakes will not whistle, but avoid putting lubricant on the inside of the pads, because in this way the brakes will not friction and will be useless. Insert the pads the same way the old ones were inserted.
Step 3. Check the brake fluid
Check the brake fluid level and add if necessary; once finished, replace the tank cap.
Step 4. Put the pliers back in place
Carefully put the calipers back on the disc so you don't damage anything. Put back and tighten the bolts holding the calipers in place.
Step 5. Put the wheel back in place
Put the wheel back in place and hand tighten the nuts before lowering the car.
Step 6. Tighten the nuts
Once the car is back on the ground, tighten the nuts following a star "pattern": tighten one and then switch to the one in front tightening to specification.
Check the manual for the torque specifications of your vehicle. This is to make sure you have tightened the nuts enough to prevent the wheel from coming off or being too tight
Step 7. Start the vehicle
Make sure the vehicle is in neutral, press the brakes 15-20 times to make sure the pads are properly positioned.
Step 8. Test the new pads
Drive at no more than 10km / h on a low-traffic road, and brake normally. If the car appears to be braking normally, repeat the test at a speed of around 20km / h. Repeat the test a few more times increasing speed until you reach 60 or 70 km / h and also test in reverse. These tests are used to verify that there are no anomalies in the installation of the brake pads and help the pads to fit perfectly.
Listen. New pads may whistle a little, but if you hear a grinding sound, like metal to metal, then the pads are likely to be in the reverse position (the inside facing out) and this is something to correct immediately
Part 3 of 3: Bleeding the Brakes
Step 1. Remove the cap from the brake master cylinder
Brake fluid becomes contaminated with dirt and other particulates in contact with the air and the mechanics of the car. It also absorbs moisture from the air by dangerously lowering its boiling point. You need to drain the brake fluid from the system before changing the pads and calipers, but you also need to make sure it is full of fluid before doing so. Check the level and add some if appropriate. Leave the cap unscrewed while you bleed the system.
The reason you need to add liquid is because you are purging liquid from the calipers themselves - the fluid still inside the system - and you need a refill in the master cylinder
Step 2. Establish the purge sequence
Normally you start with bleeding the brake furthest away from the master cylinder, so it's best to check your owner's manual before starting. Each machine is different: if you do not have the manual it is better to ask a specialized workshop.
Step 3. Insert a plastic tube into the bleed port
Plastic tubes used in aquariums are fine. Place the other end in a bottle or container where the liquid will be collected. To prevent air from returning to the system, you will need to hold the bottle or container over the tongs.
Step 4. Ask someone to apply the brakes
With the engine off, get help and ask a friend to press the brake continuously until you feel resistance. At that point you will have to unscrew the bleed screw slightly and tell to keep your foot down on the brake.
- At this point the liquid should flow down the tube to the bottle or container. Screw the screw back in as soon as your friend's foot is flat.
- Repeat the process until you see that there are no more air bubbles in the tube.
Step 5. Recheck the system for air bubbles
If you hear bubbling in the master cylinder when pressing the brake, there is still air inside. Continue purging before proceeding.
Advice
- If you are servicing the rear brakes pay attention to the parking brake system, and find the correct way to remove and adjust it.
- Check if the discs are shiny or not flat. These are things that could cause the brakes to whistle. If this happens, the discs can flatten again as long as they remain above the minimum thickness.
- Try turning the steering wheel so that the front wheels are facing out once the wheel is removed. This will make working on the front wheels easier thanks to a larger area to access the affected parts. When doing this, however, be careful not to bump into parts of the jack.
Warnings
- Always use a jack stand and blocks behind the wheels to prevent them from moving. Don't just rely on the jack.
- Do not drop the lubricant on the brake pads. In this way they will not cause friction and will be useless.
- Do not take off the brake hose from the caliper because otherwise you will let air in and it will be a big problem.
