Mazda Miata E Brake Removal

Inside the piston bore there’s a threaded screw. This is what turns to drive the piston out. It’s also what adjusts the E-brake.

There are several required modifications you must do when converting a Miata to a racecar. A big radiator is one. Racing brake pads is another. Another must-do item is removing the parking brake mechanism to reduce drag on rear pads.

Yes, you can pull the E-brake adjuster screws on the caliper all the way in, but then your E-brake doesn’t work anyway, so you might as well remove it. When you do, it also removes about 5 pounds of weight, always a good thing.

Truth be told, the job itself isn’t much fun. You’re on your back under the car for a lot of the job, and once you start in on the rear brake calipers, it’s messy. Because of the dribbling nature of brake fluid, it’s not really possible to keep things clean and tidy for this job. Have lots of brake cleaner and paper towels on hand.

To give it an overarching trajectory for the job, you essentially remove the hand-brake lever inside the car, remove a heat shield under the floor, the cables and the brackets that retain them. Then you move to the rear axle where you remove the cables from the E-brake levers on the back of the calipers. At that point, you remove all the cables, then pull the rear calipers off, disassemble them and remove the parking brake mechanicals from inside the rear caliper pistons and then reassemble the calipers with new seals. It’s a fair amount of work.

- Advertisement -

One piece of advice is to buy the caliper rebuild kits from Mazda. They cost more, but they have all the pieces you may or may not need. It’s also important to point out that the Mazda kit services both rear calipers, not just one, which helps explain the difference in price.

Let’s see if we can make it look easy.

In Japan, the E-brake is on the opposite side from the driver. Either way, it’s got to come out for racing. Peel the carpeting back to see that the handle and bracket are held in with two bolts visible in this photo.
You also have to remove the connector to the switch that turns the brake light on the dash. If your hands are slippery, you might need a pair of pliers.
Once you remove the handle, you need to remove the tall, slotted nut from the main actuator cable.
Unscrew the nut and the cable slides out of the bracket and the handle is off. The clean work of this job is now officially over. Climb under the car.
When you look up under the transmission tunnel, this is what you see: the main cable that pulls on the cables that lead to each caliper. Notice the spring clips at the rear of the equalizer mechanism that hold the left and right cables to a bracket. All this is coming off.
Remove the heat shield above where the catalytic converter used to be and toss it, or, recycle it.
The main cable has one 10 mm bolt holding it to a bracket behind where it feeds through the transmission tunnel into the interior. Remove the bracket and you can pull the cable through to the underside of the car.
The spring clips pry out with a large screw driver. Once you pull both clips, the whole assembly practically falls off.
See? Told you it practically falls off.
Now follow the cables to the rear of the car and remove all the retainers that hold the cables to the chassis. On the right side, some of them are hidden behind the black plastic splash panel by the fuel filter.
The cables attach to a spring-loaded lever on the back of the rear calipers.
Two 14 mm box wrenches let you break loose the retainer nuts that hold the cable to the bracket on the rear of the caliper.
This is a good shot of the bracket and lever with the cable removed.
Remove the rear caliper. This part of the job is done on a workbench with a vise. Remove the bolt on the right, which holds the cable bracket. The one on the left covers up the E-brake adjuster screw. Remove it, too.
An impact wrench is helpful and speeds things up.
With a pick tool, you can remove the dust boot from caliper piston.
Use an Allen head to turn the adjuster screw on the back of the caliper to drive the piston out of the bore.
It will get to a point that the adjuster screw no longer pushes the piston out. If you’re lucky, you can pull it the rest of the way out by hand. If not, use a pair of Channel Locks to grab the piston outside the groove that encapsulates the dust boot. Do not grab the piston with Channel Locks inside the groove because you can damage the sealing area of the piston.
Inside the piston bore there’s a threaded screw. This is what turns to drive the piston out. It’s also what adjusts the E-brake.
The adjuster is retained by a snap ring, but there isn’t a pair of snap ring pliers in the world small enough to fit into the piston bore, so you use two pick tools to grab the snap ring. This will take you a few tries, and maybe some profanity to get it out.
There’s the snap ring. Remove it and the adjuster screw will come out. While you’re at it, remove the piston seal in the bore and clean everything out. Mmmm, brake cleaner.
When you pull the screw out, there’s a small steel “hot dog” in the end of it. This will not be needed when reassembling the caliper.
But before you throw the hot dog away, put it inside the threaded bore inside the piston and thread the adjuster screw into it. This will remove the E-brake mechanism inside the piston.
The adjuster screw pries the E-brake adjuster out against the hot dog. Now, you can set the hot dog aside.
Put a new seal on the adjuster screw, put it back in the piston bore and reinstall the snap ring. This is a critical step. If you do not reinstall the adjuster screw in the bore, the caliper will leak like mad when you step on the brake pedal. Don’t ask how we know this.
After you inspect the piston for galling or wear and wire-wheel the gunk off it, install a new dust boot on the piston.
Slide the dust boot down to the inside lip of the piston and hang it off the end. It’s easy for it to slip off, so you’ll probably make more than one attempt. This will help you get the lip inside the groove on the caliper, which you cannot do when the piston is already in the bore.
When it’s seated properly in the groove, the dust boot will sit flat on the caliper.
You should be able to press the piston in by hand. The dust boot will drop right into the groove on the piston. Now you can put the caliper back on the car and do the other side. Yeah, it’s a fair amount of work.
Image courtesy of Eric Green

Join the Discussion