2016 Mazda CX-5 Elec Parking Brake - Need Help

Joined
Oct 25, 2022
Messages
13
Location
Alberta, Canada
Long time lurker, first time poster! Need some help/advice:

About 3 weeks ago, I changed the rear rotors and brakes (Akebono) on my wife's 2016 Mazda CX-5. It has about 92,000kms (60,000 miles). I had the rear end jacked up, did both sides as best I could (using appropriate grease behind the pads and on the pad ears, cleaning and re-greasing slider pins, cleaning the calipers, using new hardware, putting anti-seize on the hubs before installing new rotors, etc.), but I FORGOT to put the vehicle in maintenance mode FIRST. So, while the rear calipers were supported and hanging on coil springs, I then put it in maintenance mode, following the: ignition on, depress EPB and gas pedal and hit the start-stop button 3 times... This is the result:

2022-10 - Brake Piston Extended.JPG


The piston's on both rear calipers fully extended and were loose, as if they had been popped out of their threads. I loosened the bleeder and tried to then push the calipers in - to no avail. That is why they look wet, just a bit of old brake fluid from the bleeder.

Now, I knew about the EPB maintenance mode procedure, but typically when I had done rear brake jobs in the past, I would just twist and press the piston at the end, when I was ready to install them on the new pads (& rotors). The result of this was a few hours of frustration trying to solve it myself. A friend of mine has previously recommended a local mechanic who does house-calls in the evenings and he came and helped me get the pistons to re-engage. He removed the electronic parking brake and there was a small allen-key bolt on the rear side of the caliper that he gently twisted while pressing and twisting the piston and eventually it re-engaged and went in. I then installed the calipers and did a brake flush with his help and we tested the EPB 3 times after and it all seemed to work fine.

The issue I am now having is this: We don't normally use the EPB at all (except to reset TPMS or in other rare scenarios), but when we now engage it, the parking brake light flashes, as though there is a malfunction. It does work and it holds the vehicle in place. But, it won't disengage. My wife also commented on how it sounds different than before (I don't remember but she seems to). To get it to disengage we have to turn the car off, wait a min or so, turn it on, press on the brake pedal and then press down on the EPB switch and it will disengage. Is there any way to correct this? Did we do something wrong while playing with that allen-key bolt? I would prefer to not take it to the dealer.

Also, I did some research and my VIN and my caliper # are not included in the TSB for rear brake caliper recalls.

Appreciate any suggestions or ideas you may have!
 
Last edited:

GoOil97

Thread starter
Joined
Oct 25, 2022
Messages
13
Location
Alberta, Canada
Try maintenance mode again, with everything assembled to get a proper reset
That is a good idea that I can easily do at home. Will try that this weekend. Thanks for the suggestion. I don't have a scan tool that can fulfill this function.
 
Joined
Aug 12, 2013
Messages
1,292
Location
Alberta
My 2013 mechanical e-brake works like you were expecting yours to work...just screw it back in. I think if you go into and out of maintenance mode, error free function will be restored. The only other thing is that you may need to use a scanner to delete any stored codes.
 
Joined
Aug 30, 2004
Messages
28,606
Location
CA
Why? The rear brakes work fine under normal hydraulic operation.
Your parking brakes do not work properly, not being able to disengage is an issue. I suspect that when the pistons traveled beyond their normal range, something was internally damaged in the caliper assembly. If the issue isn’t resolved by clearing the faults or thru other software means, you will need to replace the caliper.
 

GoOil97

Thread starter
Joined
Oct 25, 2022
Messages
13
Location
Alberta, Canada
We use it so rarely I don’t even remember! I think you have to though.

I tried putting it in maintenance mode and then taking it out and it didn’t seem to fix the problem. It has since gotten quite cold here in central Alberta and I don’t have a heated garage. I will leave it until the spring when it warms up. Everything works fine, brakes work perfect and since we don’t use the EPB I’m not to worried. I definitely don’t want to take it to the dealer.
 
Top