Asked in Mazda 6
Mazda 6

How do you change the rear brakes on a 2004 Mazda 3?


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I'll assume you know how to remove the tire, or please stop now. You will need a 7mm hex wrench, 6" C-Clamp, hammer, long nose pliers and a screwdriver. Eye protection and work gloves are suggested for your safety as there is a lot of dust and debris.

Start by using either the pliers or screwdriver to remove the retainer wire from the caliper. This should pop right out, and it is a good idea to wear eye protection because of it. Now reach around the caliper to feel and remove the plastic caps covering the hex head slide bolts (facing the inner wheel well). Use your 7mm hex wrench and loosen both slide bolts and pull out enough to clear the caliper bracket. Use the hammer to tap the caliper away from the bracket and worn pads. Remove old pads from bracket. Now here comes the tricky part no one ever seems to figure out: Compressing the piston enough so to slide the caliper back over the rotor with much fatter new pads. First, pop the hood and remove the brake fluid reservoir cap to make compression easier. Then, (this is the tricky part) pull up the parking brake lever. Using the long nose pliers, insert the end of the pliers into the two holes at the end of the piston in order to turn the piston clockwise many times.

Release the brake and use your 6" C-Clamp to depress the piston all the way until flush with the boot. To make depression easier, you will want to make sure the end of the closing screw is on top of the piston so as you turn to close the C-Clamp, it will also turn the piston clockwise. You may need to alternate between the pliers and the C-Clamp until piston is fully recessed to your satisfaction. If the piston is recessed enough, go ahead and install the first brake pad on the piston. This pad has a set of 3 wires on the reverse side that clips on the piston. You can easily accomplish the pad attachment by sliding the bottom clipping wire of the pad onto groove of the piston and then pushing the pad to one side (left or right whichever is easier) to allow the left or right wire to catch. Once it catches into the groove, push the pad in the opposite direction until the last clip catches into the piston groove. You may need to adjust the clipping wires so to make them catch more readily using a flat head screwdriver or pliers. Once installed, insert the other pad.

NOTE: If you find that you depressed the piston so much that you can't get the wires to clip onto it, you can use the long nose pliers to rotate the piston counter-clockwise to raise it a bit.

Check to see if there is enough clearance between the pads to clear the rotor. You should not have to use any kind of force to slide the caliper into place, so to not damage your new pads. If not, repeat the piston depression process using the pliers and/or C-Clamp.

Slide the caliper over the rotor until the slide bolts are aligned with insertion holes. Again, use your 7mm hex wrench to secure the bolts. Replace retaining wire to the front of the caliper over bracket, and snap caps back over the slide bolts. Don't forget the tires and to tighten the cap back on to the reservoir. Good Luck! This info will make this job a snap (20 minutes per tire if all goes well). edited content for safety concerns.