Screwed up brake job - Help!

destroebl

2018 CX-5 Touring FWD
I have done brake jobs on multiple other vehicles, and I did watch a couple videos before attempting this, but apparently the videos I watched missed the part about putting the car into maintenance/service mode before attempting to do the rear brakes, or maybe I was looking at earlier models and didn't realize it?

After doing the front brakes without issue, I had the car on jackstands, took off one of the tires/calipers, and started to turn the calipers to push them back in, but then decided to double check this process and make sure turning was correct. I turned it maybe... 1/12th of a turn? Maybe not even that much. After googling again, I saw that you push it in rather than turn, and I saw the information about putting it into maintenance mode to disengage the emergency parking brake (EPB).

I put it into maintenance mode, but somehow also engaged the EPB at the same time? It was in maintenance mode with the (P!) symbol, but the EPB was now on, too? It fully pushed out the piston in the caliper and was not budging back in. After messing with the EPB and maintenance mode more, it looks like the piston fully pushed out! It is now kind of loose, and is not easily going back in. Also, I'm getting all kinds of warnings and lights on the panel when the car is on.

Did I just screw my caliper, and now I need to replace it? If so, any ideas on where to get one of those on a Sunday and a guide to replace it? Haha, oh boy... thanks in advance for any help you can provide!
 

There are several posts here where people claim to have fixed the conundrum you’ve found yourself in. Check out the very last post, and I think post #25. Best of luck!
 
I did actually do some digging around before posting and didn't find anything that matches my problem exactly. My piston was totally loose, not just fully extended. Somehow it got pushed OUT of the caliper!

AND to make matters worse, when I went back out to look at it more a minute ago, I saw that the caliper had fallen over a bit (it was suspended by a bungee cord), the piston came out entirely and brake fluid was leaking!

Now, I definitely need a new caliper and probably have to have the brake line serviced, right? I don't know where I can get calipers on a Sunday and I really don't want to have to tow this to a shop, UGH. If I had the replacement caliper, it seems straight forward. Really frustrated that I somehow missed the maintenance mode aspect.
 
I’d remove the EPB motor and see if you can get the piston back in the caliper. If all goes well, it sounds like you’re just going to have to be thorough with bleeding the brake system. That’s the extent of what I can suggest though having only replaced the pads and rotors on my plain Jane ‘13 Sport.
 
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Thanks for the feedback! I was worried that with the piston fully out of the caliper, it would be hard to get it back in and the boot back on, but maybe it's worth a shot. If anyone has any experience with that, I'd appreciate it.

Otherwise I'm going to frantically hunt for a place that has mazda rear calipers in stock or find a car to rent for Monday. UGH!

Thanks again.
 
Thanks for the feedback! I was worried that with the piston fully out of the caliper, it would be hard to get it back in and the boot back on, but maybe it's worth a shot. If anyone has any experience with that, I'd appreciate it.

Otherwise I'm going to frantically hunt for a place that has mazda rear calipers in stock or find a car to rent for Monday. UGH!

Thanks again.
There is a thread with someone who was able to fix them. I think basically he disassembled them and then reassembled them in the proper reset condition.
 
Thanks for the feedback! I was worried that with the piston fully out of the caliper, it would be hard to get it back in and the boot back on, but maybe it's worth a shot. If anyone has any experience with that, I'd appreciate it.

Otherwise I'm going to frantically hunt for a place that has mazda rear calipers in stock or find a car to rent for Monday. UGH!

Thanks again.
I believe the back of the piston has a screw mechanism attached to it. This mechanism in turn engages with the EPB motor assembly. If the piston has fallen out, then it has become disengaged with the screw mechanism. Start by unplugging and then removing the EPB motor assembly. If the piston is completely out, look inside the body cavity of the caliper. You might be able to find the piece that is supposed to be attached to the piston. (The brake fluid is lost, so don't worry about the rest of it leaking out while doing this). My gut tells me you might be able to salvage the caliper if you can reassemble the piston and screw mechanism and get it back in the caliper body. You can then retract the piston by turning the screw clockwise. As someone earlier stated, do not tun the piston itself. If you can manually retract the piston, then you can re-attach the motor assembly after that. Keep us posted.
 
The diagram in the TSB is pretty good. The EPB motor (A) turns the screw (B) to retract or compress the the brakes just enough to apply the braking for parking. I believe the purpose of maintenance mode is actually not to protect the motor as much but to retract the ball and ramp (C) so the piston goes straight in. In your case, I suspect the screw (B) got pushed out so far it was no longer in the collar.


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Success! I was not optimistic about getting it back together, but, yes, as Buzzman pointed out, the key is you have to take the EPB motor off first, and then you can get everything back in reasonably well. I was worried that my slight rotation of the piston had screwed something up permanently, or the fact that it popped out all the way was going to mean it was going to be difficult to get it lined up and inserted properly. I also saw another post of someone who had the same issue and the only advice was to bring it to a brake shop to reassemble!

With the EPB motor off, though, it wasn't too bad. I turned the EPB screw (B) all the way in, clockwise. It was a little tricky getting the rubber boot/dust shield back in the right spot, but putting it on the piston first and having the boot fully extended out made it easier to get it to sit in the lip of the caliper BEFORE trying to get the piston in at all. Once the boot was on the lip, I was able to massage the piston into place and then simply push the piston in. One poster at the very end of the thread about Ruthrj linked above said you may need to rotate it to go in from this spot, but it actually was able to be pushed in all the way fine. From there I took it out of maintenance mode and tried to figure out if this was actually going to fly.

I was still worried about it leaking, the boot not being in properly, etc, but after testing the brakes manually in the garage and inspecting for leaks, everything seemed ok. I did have to bleed air out of the brake lines, but after that, a test drive confirmed that the brakes are all functioning, no warning lights, etc.

Thanks to Ruthrj, Buzzman, and Mazdio for the help! Great community here guys!
 
Yeah great job and thanks for posting your solution.

I've always worked on my non epb brakes but after reading this I may let my mechanic do the rears epb.

Also for anyone else that gets in a jam/jumble, it's always better and cheaper to get a car rental for a day or two(if you don't have a spare car) instead of having it towed to a dealership. That's if you think you might be able fix it.

Rental came in handy when working on a hard to reach alternator that took longer than expected. Exaggerating but it was crammed so tight that you pretty much had to remove the whole engine and/or the whole suspension system to get the alternator in and out.
Smaller hands would have been handy to.
Ladies are so blessed.
 
Yeah great job and thanks for posting your solution.

I've always worked on my non epb brakes but after reading this I may let my mechanic do the rears epb.

Also for anyone else that gets in a jam/jumble, it's always better and cheaper to get a car rental for a day or two(if you don't have a spare car) instead of having it towed to a dealership. That's if you think you might be able fix it.

Rental came in handy when working on a hard to reach alternator that took longer than expected. Exaggerating but it was crammed so tight that you pretty much had to remove the whole engine and/or the whole suspension system to get the alternator in and out.
Smaller hands would have been handy to.
Ladies are so blessed.
It’s really not any different than doing non epb brakes, just make sure vehicle is put into maintenance mode.
 
Yeah great job and thanks for posting your solution.

I've always worked on my non epb brakes but after reading this I may let my mechanic do the rears epb.
There are good write ups with details on this forum. When you put the brakes in maintenance mode you get a confirmation.
 
I need some help too - slightly different! I made a series of mistakes this morning and I could really use some advice. I had a binding caliper on by 2016 CX-5 Rear wheel - I know there is a TSB but I am way out of warranty. Anyway, as I have done before, I pulled the wheel and the caliper to clean everything.

1) In my rush, I completely forgot about maintenance mode being needed BEFORE pulling the caliper
2) After cleaning, I couldn't fit it back on, and remembered maintenance mode. I attempted to engage it
3) I think I pulled on the break lever instead of pushing. The piston was pushed completely out. No other ill effects other than not bing able to put it back together (no leaking, piston stayed in housing). All other attempts at maintenance mode since then have failed.
4) I detached the motor and turned the shaft clockwise, which seemed to allow the piston to retract. However, spinning the shaft also spun the piston. I kept doing this until I could fit the caliper back on.

Questions:
1) Does the motor normally spin the piston, or do I need to find a way to hold the piston still while backing off the screw? Which direction do I turn it?
2) Is there any way I can recover my e-brake other than taking it to the dealer? Normal braking seems ok but I have the blinking light on the button and flashing brake light on the dash.

Thanks for your help!
 
I need some help too - slightly different! I made a series of mistakes this morning and I could really use some advice. I had a binding caliper on by 2016 CX-5 Rear wheel - I know there is a TSB but I am way out of warranty. Anyway, as I have done before, I pulled the wheel and the caliper to clean everything.

1) In my rush, I completely forgot about maintenance mode being needed BEFORE pulling the caliper
2) After cleaning, I couldn't fit it back on, and remembered maintenance mode. I attempted to engage it
3) I think I pulled on the break lever instead of pushing. The piston was pushed completely out. No other ill effects other than not bing able to put it back together (no leaking, piston stayed in housing). All other attempts at maintenance mode since then have failed.
4) I detached the motor and turned the shaft clockwise, which seemed to allow the piston to retract. However, spinning the shaft also spun the piston. I kept doing this until I could fit the caliper back on.

Questions:
1) Does the motor normally spin the piston, or do I need to find a way to hold the piston still while backing off the screw? Which direction do I turn it?
2) Is there any way I can recover my e-brake other than taking it to the dealer? Normal braking seems ok but I have the blinking light on the button and flashing brake light on the dash.

Thanks for your help!
Can't help with question 1.

But had watched video few days ago...
Question 2

Turn ignition on.
Press and hold ebrake button down.
Turn ignition off then on
Pull and hold ebrake button up.
Turn ignition off then on
 
Can't help with question 1.

But had watched video few days ago...
Question 2

Turn ignition on.
Press and hold ebrake button down.
Turn ignition off then on
Pull and hold ebrake button up.
Turn ignition off then on
Thank you.

Tried it - no change. Most of the EPB stuff includes the gas pedal. Is it possible that was in the video?
 
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