Hardlymoving writes about do-it-yourself automobile maintenance on various makes and models.
Spiral Brake Piston Design
Replacing the rear brake pads on this Mazda 3 involves the extra step of screwing the piston into the caliper. Since the parking brake is tied to the brake caliper, this caliper has a spiral brake piston; the piston has to be recessed back by screwing it clockwise back into the caliper. The Mazda 6 has the same issue, including in 2002-2008.
You can screw the piston into the caliper with a caliper piston compression tool (see photos below) or with needle-nosed pliers. When using pliers to rotate the piston, you may have to apply pressure to the piston during rotation to start it on its way back into the caliper. If you don't want to use specialty tools, you can combine C-clamp pressure with plier-assisted rotation.
Using a Caliper Piston Compression Tool Set
If you choose to purchase or rent a caliper piston compression tool set—see the second photo below—one of the tool set adapters should closely match the circumference of the piston. Each adapter has two prongs that protrude from its base that are designed to mate into grooves on the piston. Once those prongs are placed, the thrust bolt, in conjunction with the thrust bolt plate, can now press on and turn the piston to begin pushing the piston back into the caliper. You can use an adjustable wrench to turn the thrust bolt sleeve counterclockwise (to remove slack buildup) while the thrust bolt is being turned clockwise to recess the piston.
This 2.5-minute video will provide you with visual step-by-step help for completing the replacement of the rear brake pads on a Mazda 3. The steps are also described lower down in the article.
This two minute video explains what causes brake squeal and how to prevent it.
I. Removing the Two Brake Caliper Bolts and Caliper
- Remove both the upper and lower brake caliper bolts. If the bolts spin with the caliper guide pins, hold the guide pins in place with either an adjustable wrench or a wrench of a size that matches the guide pin hex contact points.
- Wiggle the caliper off of the brake pads.
II. Removing the Brake Pads and Brake Pad Shims
- Wiggle both the front and rear brake pads off of the brake caliper bracket.
- Remove the brake shims from the brake caliper bracket.
III. Installing the New Brake Caliper Shims
Install the new brake caliper shims onto the brake caliper bracket. New shims will prevent the "ears" or connection points on the brake pad from moving around on the brake caliper bracket. If your shims are worn, you will notice movement when transitioning from Drive to Reverse and vice versa.
IV. Applying Brake Grease to the New Brake Pads
Apply brake grease between the brake pad and brake pad shim contact points. Brake grease will prevent rubbing friction which may result in a high-pitched brake squeal.
V. Mounting the New Pads
Angle the new brake pads onto the new caliper bracket shims. Slide the pads until they contact the brake rotors.
VI. Recessing the Brake Caliper Piston
Use either needle-nose pliers or a caliper piston compression tool to screw in the piston until it is flush with the base of the caliper piston pocket. If you are using pliers, and the piston keeps spinning and will go in, you need to apply some pressure on the piston while turning it. You can apply this pressure with a C-clamp while you are using the pliers. Once the piston threads have engaged, the C-clamp will no longer be necessary.
VII. Lubricating the Caliper Slide Pins
Pull the upper and lower caliper slide pins out of the caliper bracket and lubricate with brake grease. Lubrication will allow the caliper to "float" and adjust to a new position to keep up with the wear rates of the inner and out pad. If a caliper pin gets stuck due to corrosion or lack of lubrication, the brake pads will wear unevenly and the wheels may shake during braking.
VIII. Mounting the Brake Caliper
Mount the caliper back onto the brake caliper bracket and install the upper and lower mounting bolts through the caliper holes on to the caliper slide pins.
IX. Before You Drive
Pump the brake pedal a few times, to push the caliper pistons against the new brake pads, before driving the car.
This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.
Questions & Answers
Question: How do you remove rotors?
Answer: Remove the caliper and the caliper bracket.
© 2018 hardlymoving
John on January 31, 2019:
Thanks you’re a beast!