cruiser

I replaced my brake pads few weeks back and at that time I had problems with getting some caliper pistons back into the sleeves (doing it with screwdriver got them sideways and then I had to use pliers to rotate them into level position and then I could squeeze them in). Now when I apply brakes, pistons, most of the time, refuse to go back in - i.e. I have sticking brake pistons, causing my brakes to drag and overheating my rotors.

Anyone had also such a problem ? How to solve it ? Do I just need to take them out and lube them ? Also, I think one or two rubber dust seals are bad. Are they part of caliper rebuild kit ? Do I need to take out the pistons (hope not).

I've seen the caliper rebuild kit for both front calipers at mazdatrix.com for $30. It doesnt say what it includes though.

Thanks!

BigIslandSevens

iTrader: (4)

if the boots are ripped that is the root cause of the sticky pistons. They probably have a build up of dirt and grime preventing them from going back. The rebuild kit should include all the parts needed for 2 calipers. In each kit

It is not that bad of a job to do. And if you were going to pop the piston out to clean it anyways. you may as well rebuild them all.

They also sell the whole units built already...for the "bolt-in" replacement. But much more $$. Then you have the others to rebuild for later

cruiser

I just placed an order with mazdatrix for front calipers rebuild kit. Only $30.
Do the calipers need to come off to rebuild them ? How do you pop out the pistons ? Do you just pull them out and then clean the pistons and sleeves then put them back in (grease?) and seal with new boots ?

BigIslandSevens

iTrader: (4)

Yes the calipers need to come off. You need to pop the pistons out of them as well. This can be done with compressed air or with hydraulic pressure ( I.E.: pumping the brake pedal until the piston comes out...BUT this will make a bigger mess than needed)

The compressed air will need to be blasted in thru the fluid hole. Be sure to put a rag or stick in the caliper to prevent the pistons from blasting into the other side of the caliper. Damaging the pistons rendering them useless.

Since there are 4 pistons to remove in the fronts, i recomend pumping them out with the pedal until you can remove them by hand.I.E.: Just before they pop out of the caliper.. Other wise you will need to hold the others in place while removing them.

Once the pistons are out you need to clean the entire Bore area very well. Use a cleaner solution and a Q-tip. If there is some stuborn grit, you can take a extremely lite/fine grit sand paper and remove the grit. However this may take off the protective coating that is on the pistons. This was supossed to keep them from corroding

The piston seal is on the inside of the piston bore. Once the pistons are removed you will see them. Those need to be taken out with a dental pick or similar tool. Clean that groove like it was the last thing you ever do.!! That will cause more sticking and leaking problems than anything else.

Once all is clean, insert the new seal into the caliper. LUBE the seal with NEW brake fluid. Do not use grease or other product that can contaminate the system. Additionaly lube the bore surface with fluid too.

Install the dust boot over the piston and slide it to where you can get the lip of the boot into the groove on the caliper. Then start the piston into the bore carefully. making sure to get it in straight without knicking or pulling the new sealout and damaging the bore surface.

Push the piston all the way in and install the retaining ring . Install the caliper back on thecar, attach brake line, and repeat for the other side. Or all 4 calipers.

Then start the bleeding process at the right rear or left depending on which is further away from the master cylinder ( The left rear if your car is RHD )

That is pretty much the process in a nut shell. It is fairly straight forward to do. Not many speacial tools . I do recommend that either you buy a service manual from mazdatrix as well or download the one from www.iluvmyrx7.com

Hope I gave you an idea of the job. If you are hesitant to do it yourself, you can always just pull the calipers off, bring them into a repair shop and ask them to rebuild them for you. ( with the parts provided by you )

I am not sure of the accesability to shops where you are at. But i think yoiu can do it. Just make sure you take your time and be VERY CAREFULL!! This is the single most IMPORTANT system on the car. Your life depends on them operating properly. Make sure you test them at a slow speed first. Also pump the brakes up after they are bled to make sure that the pads come into contact with the rotrs immediatly.. instead of waiting for them to travel out to the pads.Due to them being pushed in all the way on reassembly.

Mahjik

iTrader: (1)

https://www.rx7club.com/suspension-wheels-tires-brakes-20/brake-caliper-piston-removal-333883/