Replacing Your Front Disc Brakes Made Simple: The Definitive DIY Guide
Brakes are an essential part of any modern vehicle, but they don't last forever. Eventually, the pads that clamp down on your disc-brake rotors wear out. When this occurs, they can't generate the friction needed to bring your car to a smooth halt.
Fortunately, you can replace the pads found in most vehicles' front disc brakes to save yourself some money and avoid unsafe driving conditions. Here's what you need to know.
When Should I Replace My Brakes?
The key to any successful auto repair is knowing when to apply the right techniques. You should only attempt this DIY replacement when your front disc-brake pads have worn too thin to function correctly. You can often tell it's time for a change because:
- You notice squealing, scraping or grinding sounds when you apply the brakes,
- You hear chirping noises when you're driving without applying the brakes, or
- You see brake-fluid warnings on the dashboard.
Other symptoms, like feeling vibration when the brakes are applied or noticing extremely deep grooves in the rotors, require rapid professional assistance. If you have fixed-caliper brakes, drum brakes or worn rear brakes, you should consult a mechanic.
Before Getting Started
Make sure you're ready for the job by preparing your parts and tools in advance. If you're not certain what kind of replacement to use, refer to the driver's manual for your vehicle. For instance, your specific model may need a special tool to reset the caliper piston.
Gather the Following Materials:
- New brake pads that match the ones you're replacing or the OEM part,
- Brake grease, and
- Brake fluid.
Obtain These Tools:
- Wheel blocks,
- Car jack and jack stands,
- C-clamp or special tool to retract the brake-caliper piston,
- Socket and lug wrenches,
- Turkey baster,
- Waste container, and
- A bungee cord or strong rope.
Tips to Remember
- Set aside at least an hour to complete this job.
- Finish replacing the pads on one side of the vehicle before moving to the other.
- These instructions only apply to sliding-caliper front-disc brakes.
- Wear gloves, protective glasses and a dust mask from start to finish.
- Read these instructions completely before starting work.
1. Pick and Prep the Wheel
Choose the first wheel you'll work on. Use the lug wrench to loosen the nuts, but do not remove them.
2. Position the Vehicle for Work
Park the vehicle in a clear workspace. Use the wheel blocks to ensure the car won't move. With the jack, lift the wheel you loosened. Place the jack stands beneath the vehicle as indicated in the owner's manual.
Lower the jack back down until the vehicle rests firmly on the stands. Before placing any part of your body beneath the lifted vehicle, try to push or rock it to confirm that the stands hold fast.
3. Expose the Brake Assembly
If you've ever changed a tire, this should be simple. Finish unscrewing the lug nuts on the raised wheel, and remove it.
4. Remove the Caliper
The brake caliper is generally held on by a pair of bolts. If you pull the caliper outwards, you'll see these bolts near the top and bottom of the assembly. Most have their heads facing inward towards the vehicle's center line.
Using the socket, box or adjustable wrench, loosen the bottom bolt and remove it. Then, flip the caliper assembly upwards, pivoting it on the top bolt, which may require loosening. If this fails, you can remove both bolts to lift the outer caliper off.
Move slowly to avoid disconnecting, kinking or damaging the hydraulic line. You don't want to place any strain on the hydraulic line, so use your bungee cord or rope to suspend the assembly instead of letting it dangle from the hose.
5. Take Out the Old Brake Pads
Remove the worn brake pads by taking off their retaining clips or other fasteners and sliding them out. If the pads are under 1/4" thick, they definitely ought to be replaced.
6. Install New Brake Pads
Most brake pads come with their own retaining clips. Apply the grease, which may have been included with the pads, to the clips before installing them. Insert the new pads while maintaining the same orientation the old pads were in.
7. Reset the Caliper Pistons
The pistons in the caliper assembly you removed need to be pushed back to accommodate the thicker replacement pads. Use the C-clamp to gradually move the pistons back towards the inner part of the caliper. Turn slowly, and be patient.
If there are two pistons, clamp both simultaneously with a wood shim. Avoid damaging the hydraulic line or any of the nearby rubber seals.
As you reset the pistons, open and observe the brake-fluid reservoir attached to the master cylinder. The level inside will rise as the pistons push hydraulic fluid back up the line. If it looks like it's about to overflow, use the turkey baster to dispose of the excess in your waste container.
8. Close the Caliper
If all went well, the caliper should slide back into position without hitting the brake pads. Reinstall the bolts. Tighten them securely before replacing the wheel and lowering the car back down.
Perform the same steps on the other wheels. Always keep an eye on the brake-fluid level to ensure it stays below the maximum. If it's below the minimum, add new fluid, but only after you've replaced all the brake pads.
After replacing your brake pads, pump the pedals slowly a few times before moving the vehicle. Take a slow test drive under safe conditions to be certain everything works and get used to the new feel of your fresh brakes. Happy driving!