HOWTO: Install Brake Pads, Rotors, and Lines

Introduction

The following is a step by step guide to replacing the front & rear rotors & brake pads on a 2.3L Mazda3. Note that both the 2.0L Mazda3 and the Mazdaspeed3 use 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.

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.
   
   
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.
   
   
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 pad in place over the piston, use a c-clamp or pad spreader to push the piston back into the caliper. In my case w/ a simple rotor change w/ no brake pad swap...I didn't have to compress the piston. Lube & reinstall the two caliper bolt/pin, reinstall the dust cap, and spring clip. Finally, remove the lugnut and spacer that you used to hold the rotor in place.
    
    

Rear Rotor & Pad Install / Replacement

1. Jack up car and remove wheel. Using a flat-head screwdriver pop off the spring clip. The spring clip will pop/fly off, so beware.
   
   
   
2. Find the two plastic dust caps that are just snapped-on the back of the caliper and remove them. Using the 7mm allen/hex key remove the caliper bolt/pin.
   
   
   
3. Slide off the caliper and place it somewhere as to not put any excessive strain on the brakeline. In my case, I just gently wedged it between the shock and a nearby strip of flanged sheet metal in the wheelwell. 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.
   
   
4. To remove the caliper mount bracket, locate the two bolts on the back of the rear upright. Using a ratchet, 14mm socket, and a breaker bar; remove the two bolts.
   
   
   
5. 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.
   
   
6. Slide on the new rotor, and hold it in place using a spacer and a lugnut.
   
   
7. Reinstall the caliper mount bracket to the upright. Be sure to apply some blue loctite on the bolts.
   
   
8. Install the brake pad. Simply place the outer pad on the caliper mount bracket. The inner pad needs to be slid into place on the piston. Note the flange on the piston and the clips on the back of the pad.
   
   
   
9. Slide the caliper over the outer brake pad and rotor. If you can't slide the caliper on, you may have compress the piston. To do this you will have to either get a special brake tool from and auto parts store, or simply use needle-nose pliers to rotate the piston. On the piston you will see two circluar indentions. Place the tips of the pliers in the indentions and rotate the piston clockwise to compress it back into the caliper. As with the front, be sure to first take the lid off the fluid reservoir and watch to ensure it doesn't overflow while you compress the piston.
   
   Note from Wild Weasel: I've noticed that there is a lot of commentary in the forums about people having difficulty compressing the rear pistons. I want to be very clear about this. If you haven't done rear calipers before and are not familiar with how they work, DO NOT ATTEMPT THIS with needlenose pliars. I know it can be done and have done it myself several times, but it will almost certainly be a very frustrating endeavour. If you don't own a rear caliper compressor tool, go out and buy or rent one. Many auto parts places lend them out for free. The piston has to be pressed and rotated back in. It doesn't push straight in and it doesn't screw in. The tool will press and turn at the same time, and make this job very easy.
   
   
   
10. Lube & reinstall the two caliper bolts/pins, reinstall the dust caps, and spring clip. Finally, remove the lugnut and spacer that you used to hold the rotor in place.
    
    
11. After completing the install & remounting the wheels, get into the car and press the brake pedal a few times to build up pressure, and engage and disengage the e-brake a few times. The rear brakes are self-adjusting, and it will calibrate/align the piston by the use of the e-brake.

Techna-fit Braided SS Brake Lines - (Front)

1. Check the brake fluid level, top off if necessary. Jack up car and remove wheel. Using a flat-head screwdriver and mallet remove the clips holding the brake line to the strut and to the frame mounted brake line bracket.
   
   
   
2. Place a catch can/basin under the caliper to catch the brake fluid. Using a 13mm flare nut wrench, unscrew the brake line from the caliper.
   
   
3. Using a 16mm open end wrench to hold the top and a 10mm flare nut wrench to turn the bottom nut, to loosen the compression fitting. Unscrew the bottom 10mm flare nut until it is disconnected from the rubber brake line.
   
   
   
4. Attach the brake line to the hard line. Using an 17mm flare nut and a 10mm flare nut wrench, tighten the bottom flare nut.
   
   
   
5. Slide the retaining collar up the brake line and insert it into the brake line clip on the strut. Using a 13mm flare nut wrench, attach/tighten the flare nut to the caliper. Gently pull on the section between the strut mount and the caliper to ensure that there is a just a little slack in the brake line, this is to ensure that there is no strain on the lines when the wheels are turned. Re-install the (2) brake line retaining clips on the strut and the frame bracket.
   
   
6. Follow the procedures to properly bleed the brake lines, and purge any air out of the system. After each line change, top off the brake fluid level in the reservoir using Dot3 brake fluid.