E-brake issues - repair or replace

smfitch

Member
:
CX9
Hello everyone- I'm doing everything I can to figure out a way to avoid a $2100 dealer bill. My wife has a 2016 CX-9 with about 85K miles. A couple of weeks ago I did a SECOND rear brake job for her (first one was about 2 years ago). I've done one before, and I knew how to retract the calipers to get it into service mode. I did the same procedure, and I could hear the pistons pulling back. After getting the new rotors and pads on I realized the pistons didn't go back near far enough (like barely moved). I had my wife do the procedure and I could see the piston turning, but not pulling back.

Not having any other option (at least not knowing any others) I figured out a way to remove the motor and get the calipers pushed back. At that point I got a bunch of flashing brake warning lights so I figured I must have really screwed things up.

I dropped it off at the dealer this morning. They're recommending not only replacing the motors, but also replacing the calipers so they can "talk" to each other. They're also recommending that the control module be replaced just to be "safe.". Parts for just the calipers and motors are about $900, labor is $830.

On a separate note: is it common to do two rear brake jobs within 100K miles? My 6 had it's first rear brake job a couple of months ago and I have 114K miles (and the pads were still decent).

Thanks in advance!
Steve
 
:
Mazda CX-9 Signature
So after service mode, did you use any tools to push the piston back into the caliper? Or did you solely rely on the motor to retract the piston?

After you removed the motor off of the caliper, did you use the torx/hex key (I forget which one) to manually retract the pin before pushing the piston back into the caliper?

Without these clarifications, my suspicion is after you removed the motor, you broke the caliper by not turning the piston back in.

I linked a video below that shows how it can be done if you remove the motor.

And yes, it's normal to change at your interval

I'm surprised they didn't suggest you to replace the vehicle just to be super duper safe 😂
 
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smfitch

Member
:
CX9
So after service mode, did you use any tools to push the piston back into the caliper? Or did you solely rely on the motor to retract the piston?

After you removed the motor off of the caliper, did you use the torx/hex key (I forget which one) to manually retract the pin before pushing the piston back into the caliper?

Without these clarifications, my suspicion is after you removed the motor, you broke the caliper by not turning the piston back in.

I linked a video below that shows how it can be done if you remove the motor.

And yes, it's normal to change at your interval

I'm surprised they didn't suggest you to replace the vehicle just to be super duper safe 😂
Sorry for not responding sooner (I thought I would get an email notification). Thank you for your reply! This is good stuff.

So today I decided to take everything down to zero and start fresh. The motors work fine (took them out and attached power to make sure they turn). I also made sure the pistons were "north south" based on the hole in the caliper.

Now I get the e-brake to work only half the time. The passenger side locks and unlocks with no problem but the driver's is a hit or miss. If I cycle through turning on the ignition I can get the driver's side to work. Other times it doesn't work at all and I get the yellow "P" on the dash (passenger side is still functioning).

Here's some more information: when I did the brakes initially and had trouble with the passenger side, I decided to remove the caliper from the driver's side THEN try to go into maintenance mode again (yeah, call me stupid... I'm feeling it). I realized my mistake quickly, but not after the piston had been extended too far. I couldn't get a tool on the piston to push it back in so I ended up pulling out the piston so I could get the spindle to go back down. When you say "broke the caliper" could this have something to do with it?
 
:
Northeast
:
2020 CX-5 Tour
I couldn't get a tool on the piston to push it back in so I ended up pulling out the piston so I could get the spindle to go back down. ...
Did you get the air out of the system after reinstalling the piston back into the caliper? If not, that might be the reason for the EPB errors.
 

smfitch

Member
:
CX9
Did you get the air out of the system after reinstalling the piston back into the caliper? If not, that might be the reason for the EPB errors.
Sorry for not responding sooner (I thought I was getting notifications but they're not coming through).

Yes, I thought I had done a job of getting all the air out, but I'm starting to wonder if there is a code that needs to be reset?

Here's some more information- I found that when I shut the car OFF, the e-brakes will work and both wheels lock up.
However, when I engage the e-brake while the car is on, only one side will engage, and I get the flashing red brake and flashing yellow "p" light
 

Antoine

Administrator
Sorry for not responding sooner (I thought I was getting notifications but they're not coming through).
Side note here…Have a look at your account settings, specifically “Preferences”…If you need further assistance, feel free to PM me, thanks!