Mazda3i rear caliper piston seal

Messages
13,293
Location
ROCHESTER, NY
On my daughters '06 Mazda3i(2.0L) rear caliper piston seal/boot is torn causing moisture to get in past the seal and the piston to NOT Retract. The caliper/piston IS NOT FROZEN/SEIZED as, with a little elbow grease, I have freed it up by turning in the piston(turn in, not pushed in piston)... *This car uses the disk brakes as the parking brakes and does not have P-Brake shoes under the rotor hat. That being said, when turning in the caliper piston(while freeing up the stuck piston), the seal/boot has torn even more in the process and I would like to replace it I want to replace the seal and I have found this at AAP, part #15293 at the top of the page: http://shop.advanceautoparts.com/p/econo...ents#fragment-1 Right now(after freeing up the piston), it is reacting as it should and is not hanging. But, with foul weather approaching, I want to replace the seal/boot to eliminate the contamination(rain/dirt/road salt) that will cause the piston to finally seize for good & locking the driver side rear brake against the rotor. Prior to this, the brakes pads were only holding on mildly after the brake pedal was released but, not causing full lockup and the wheel could still be turned by hand(after releases of the brake pedal) though, I could feel the total lack of freedom compared to the other side!(DID I SAY THIS RIGHT?) My question is: Do I have to remove the caliper(from the car) and remove the complete piston(itself) to install the new seal/boot? I didn't buy this seal/boot yet and I just want to make sure it's a quick install. And questions you may have that I did not explain well/correctly, please ask. Thanks In Advance, CB
 
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JHZR2

Staff member
Messages
46,137
Location
New Jersey
If the seal is compromised, chances are there is corrosion. I'd not chance it, even if on the rear.
 

Char Baby

Thread starter
Messages
13,293
Location
ROCHESTER, NY
OK! But, for $6 for the seal compared to $101 for a reman caliper, I'd like to try this first smile Moving the seal away from the piston, there was some debris that fell out from the seal. The piston is still nice and shiny with no scratches and is now moving freely as it should. And, I bled the caliper. But, to answer my question, when installing the new seal, does the piston need to be removed from it's caliper cylinder in order to install the the seal or is it a "Fit Over" seal...I'm not sure!
 
Messages
968
Location
Battle Creek, MI
Yes you will have remove the piston from the caliper because there is a square cut o-ring inside the caliper bore that needs to be replaced. To remove the piston the best method is to use compressed air, but be very careful. Plenty of how to videos on YouTube.
 

Char Baby

Thread starter
Messages
13,293
Location
ROCHESTER, NY
Originally Posted By: SVTCobra
Yes you will have remove the piston from the caliper because there is a square cut o-ring inside the caliper bore that needs to be replaced. To remove the piston the best method is to use compressed air, but be very careful. Plenty of how to videos on YouTube.
Thanks, I just watched a video of a Mazda Miata front caliper(not the rear as I have). But, should be similar for the rear. I am hoping to find an exact video for what I need! This should help me to see better, the process for the screw in type piston and all the parts needed. Plus, any tips the video can show that will help speed up the process!
 
Messages
2,287
Location
Canada
Originally Posted By: Char Baby
when installing the new seal, does the piston need to be removed from it's caliper cylinder in order to install the the seal
Many designs use the piston as the retainer for the dust boot (the part you want to replace). This means the piston has to be removed in order to replace the dust boot, like in the Miata video posted above. Some designs use a wire spring to retain the dust boot in the caliper bore. In those cases, you can remove the boot without removing the piston. I suspect yours is the kind like in the Miata video posted above. You can pull the piston with the caliper on the car, but -- and TRUST me on this -- you will make a horrifying mess as fluid drips EVERYWHERE while you work. I actually tried this once, just to see if it could be done; and I can tell you that doing so is a very bad idea. Do the job right: Pull the caliper.
 

Char Baby

Thread starter
Messages
13,293
Location
ROCHESTER, NY
I am replacing the caliper with a reman, instead of the piston seal. Didn't want to have any unexpected issues after getting into the job. This is a no brainer! Got a $50 off $100 from AAP through the nice folks in the "Sales/Rebate Section" and jumped all over the code #. The reman caliper was $101.99 + tax/core. Can read below! _________________________________________________________ [Quote:CharBaby] I just jumpped all over this code #WD35 and got one reman rear brake caliper($101.99) + $45 core charge($146.99) all for $96.99 + tax($104.75)! And, I still have the $45 core charge money coming back when I return the core! Total money for this will be($59.75) and 5% cash back(credit) for using Shop Discover.(~ $3)
 
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