HOWTO: Install Mazda3 Front Brake Pads and Rotors

Introduction

The following is a step by step guide to replacing the front rotors & brake pads on a 2.3L Mazda3. Note that the 2.0L Mazda3 uses different parts than those shown here, so while these instructions can be used as a general guide, things like torque specs or other details specific to this car may not apply. Also note that the Mazdaspeed3 has entirely different brakes and these instructions do not apply at all.

Bleeding the Brake System

If you are only replacing the pads and rotors, you will not normally have to bleed the system unless you've found your pedal feel to be mushy and suspect there is air in the lines.

If you are replacing the lines though, or otherwise opening any parts of the system which may let in air (this does not include removing the reservoir cap) then you will have to bleed the lines to purge any air. Generic instructions for doing so can be found here.

Preparation

1. Ensure that the car is in gear and the parking brake is off.
2. Chock the wheels to ensure the car doesn't roll.
3. Jack up the side of the vehicle and secure with sturdy jack stands. Never work under a car supported only by a jack.
   
   • It is recommended that you use stands rated for at least 3 tons each.

Front Rotor & Pad Install / Replacement

1. Remove the wheel.
2. Using a flat-head screwdriver pop off the spring clip. The spring clip will pop/fly off, so beware. I would hate for you to lose an eye to an errant spring clip.
   
   
   
   
3. Find the two plastic dust caps that are snapped on the back of the caliper and remove them. Using the 7mm allen/hex key remove the caliper bolt/pin. To bleed the brake when changing pads, the bleeder valve is circled in orange.
   
   
   
   
   
   
4. Slide off the caliper and place it on the upright. Using a piece of wire or string tie/hang the caliper on the strut to prevent strain on the brake line. If you are swapping brake pads, the pad closest to you is just held by the caliper mounting bracket. The other pad is clipped to the caliper piston.
   
   
Note that you can skip the next step if you are not replacing the rotors. The caliper mount bracket does not need to be removed to change the pads.
5. To remove the caliper mount bracket, locate the two bolts on the back of the front upright. Using a ratchet, 17mm socket, and a breaker bar; remove the two bolts.
   
   
   
   
6. The rotor should now be free, so just slide off the stock rotor from the hub/upright. If the rotor doesn't come off easily, it is probably just rusted on. Using a mallet, just tap the along the circumference of the center part of the rotor to jar the rotor free from the hub.
   
   
7. Slide on the new rotor, and hold it in place using a spacer and a lugnut.
   Holding it on like this isn't critical, but is convenient if you can do it.
   
   
8. Reinstall the caliper mount bracket to the upright. Be sure to apply some blue loctite on the bolts.
   
   
9. Install the brake pad. Simply place the outer pad on the caliper mount bracket and clip the inner brake pad to the caliper piston.
   
   
10. Slide the caliper over the outer brakepad and rotor. If you can't slide the caliper on, you may have to compress the piston.
    To do so, take the lid off the brake fluid reservoir and ensure that it is not full to the top. If fluid has been added, this may be the case and some may have to be removed. When the piston is pushed back in, the fluid level will rise and you absolutely do not want to spill any. Brake fluid is extremely corrosive to paint.
    
    With the old pad in place over the piston, use a c-clamp or pad spreader to push the piston back into the caliper. In my case with a simple rotor change and no brake pad swap, I didn't have to compress the piston. In any case where you're changing brake pads, you'll need to do this.
    Clean, lube & reinstall the two caliper bolt/pins. Reinstall the dust cap, and spring clip.
    Finally, remove the lugnut and spacer that you used to hold the rotor in place.