EPB Caliper Question

I have early 2016 CX5 supplied with the potentially defective rear calipers that can prevent the e-brake from fully releasing. Just had first experience of e-brake not releasing. After a few tries it released and I will not use it again until the calipers are replaced. Bought two new calipers from Mazda. I've changed calipers on other cars but this is my first time with e-brake. I know about putting EPB in and out of Maintenance Mode and pushing in piston (not turning) - have done this in the past for pad replacement. Here's my question: I expected the new calipers to come from factory with piston fully pushed in so I could install them with the new pads and then take EPB out of Maintenance Mode. However the new calipers do not appear to have the piston pushed in. Does anyone know proper procedure? Should I try to push in the piston? How can I be sure the caliper internals are backed off similar to what would be done by putting it into Maintenance Mode to allow the piston to be pushed in without damaging anything? Hope someone has experience with this and can share.
 
:
Mazda CX-9 Signature
Just a thought...

If the motor is off the caliper then it should be safe to push in

Or

Maybe bolt the motor to the caliper and plug in the harness. Put in maintenance mode so you know the motor will back the piston in and then you can safety push it in.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
I have early 2016 CX5 supplied with the potentially defective rear calipers that can prevent the e-brake from fully releasing. Just had first experience of e-brake not releasing. After a few tries it released and I will not use it again until the calipers are replaced. Bought two new calipers from Mazda. I've changed calipers on other cars but this is my first time with e-brake. I know about putting EPB in and out of Maintenance Mode and pushing in piston (not turning) - have done this in the past for pad replacement. Here's my question: I expected the new calipers to come from factory with piston fully pushed in so I could install them with the new pads and then take EPB out of Maintenance Mode. However the new calipers do not appear to have the piston pushed in. Does anyone know proper procedure? Should I try to push in the piston? How can I be sure the caliper internals are backed off similar to what would be done by putting it into Maintenance Mode to allow the piston to be pushed in without damaging anything? Hope someone has experience with this and can share.
Just in case you haven’t read this TSB:

TSB R052/16C - Noise from REAR BRAKE/Trace of Rear Brake Dragging

There’re many details on rear disk calipers and a parts list you need to replace them in the TSB. Make sure to get all parts you need and check the date code making sure you’ve got new and revised rear calipers.

Then read the “Rear Brake Caliper Removal / Installation” section from this Mazda Factory Workshop Manual. You can also find the torque info for every bolt and nut on rear brakes in the manual.

Workshop Manuals for 2018 CX-5

Looks like it’s very important that you keep the groove aligned when you push the piston in.
8DB7567F-C309-4F88-8CF7-4C8D7A477BF8.jpeg
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
⋯ Bought two new calipers from Mazda.
Do the rear brake calipers you got come with the electrical parking brake motor gear unit?

Parts list to replace rear disk brake calipers from TSB R052/16C:

2016 CX-5
Part NamePart NumberQ’tyMSRPSale Price
CALIPER (R)KAY0-26-61XA1$178.51$127.44
CALIPER (L)KAY0-26-71XA1$181.13$129.31
GASKET9956-21-0004$2.78$2.09
SEAL KIT, MOTORKAY0-26-44Z2$15.10$11.33
PAD SUB SET,KAY0-26-48Z1$80.78$58.64
PLATE, DISCK011-26-251B /
K011-26-251C
2$99.95$72.55
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
And 2 pages of important info from TSB R052/16C:

35FD6FAF-DFA2-4851-AAEE-4FA199C52C9B.jpeg

765AC33B-15CE-4838-8F16-B93EF3566D81.jpeg
 
:
Ottawa, Ontario
:
17 Mazda 6 GT
From everything I've seen and read, the motor can be unscrewed from the caliper quite easily. That should allow you to push the piston in. You can also manually retract the plunger that moves the piston by turning the motor with a screwdriver. You'll have to look it up and double check it (don't take my word for it in other words..lol), but I believe turning the motor screw clockwise retracts the piston.
 
Here's an update. I installed the new calipers yesterday. Everything I was concerned about turned out to be no problem. Make sure you get new crush washers (2 per caliper) for the fluid connection and a new O-Ring for the E brake motor housing. The piston in the caliper came in the retracted position so all I had to do was put the E-brake in Maintenance Mode, swap the existing motor to the new caliper, install new pads, install the caliper and take out of Maintenance Mode. E-Brake works perfectly now. Unfortunately the one thing I wasn't worried about turned out to be a huge PITA - bleeding out the air. Wasn't worried about that since I've bled brakes umpteen times over the years. I filled the calipers as much as possible before installation and used normal bleeding method. I still can't get all the air out after bleeding a zillion times. Its drivable but not as good as it should be so I guess I'll take it to a garage and see if I can get someone to do a better job than I can with the bleeding, maybe using vacuum or pressure unless someone here has any suggestions or experience with any special procedures for a CX-5. BTW, it's terrible that Mazda didn't have a recall on the caliper problem. Shame on them for not taking care of what is a design problem. Mine was out of warranty so I had to pay for the calipers (about $200. each including seals).
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Here's an update. I installed the new calipers yesterday. Everything I was concerned about turned out to be no problem. Make sure you get new crush washers (2 per caliper) for the fluid connection and a new O-Ring for the E brake motor housing. The piston in the caliper came in the retracted position so all I had to do was put the E-brake in Maintenance Mode, swap the existing motor to the new caliper, install new pads, install the caliper and take out of Maintenance Mode. E-Brake works perfectly now. Unfortunately the one thing I wasn't worried about turned out to be a huge PITA - bleeding out the air. Wasn't worried about that since I've bled brakes umpteen times over the years. I filled the calipers as much as possible before installation and used normal bleeding method. I still can't get all the air out after bleeding a zillion times. Its drivable but not as good as it should be so I guess I'll take it to a garage and see if I can get someone to do a better job than I can with the bleeding, maybe using vacuum or pressure unless someone here has any suggestions or experience with any special procedures for a CX-5. BTW, it's terrible that Mazda didn't have a recall on the caliper problem. Shame on them for not taking care of what is a design problem. Mine was out of warranty so I had to pay for the calipers (about $200. each including seals).
What method did you use to bleed rear calipers? Have you tried two-person brake bleeding method?
 
Got quite a bit of air out at first before switching to the tried and true "two person" method. I have tubing with end immersed in brake fluid in a clear plastic container so that I can observe bubbles. I got a lot of air out of course but not all. Now at each wheel (all four) I get bubbles during two pedal strokes. Then on the third stroke only fluid so you think you've got it all. Same thing at next wheel and next wheel. However repeating a wheel already done, same thing, bubbles for two strokes. I've gone around the car many times always the same result, air bubbles on two strokes then clear fluid. Have gone through 2 ½ qts. of fluid. I've successfully bled brakes many times in the past so am careful to not open bleeder screw until my wife is pushing down on the pedal and I always close the bleeder screw before she releases the pedal. She's a good sport and has always helped me do this in the past but after so many tries this time I'm sure she's not too keen on having another go at it! This will probably cost me something.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Got quite a bit of air out at first before switching to the tried and true "two person" method. I have tubing with end immersed in brake fluid in a clear plastic container so that I can observe bubbles. I got a lot of air out of course but not all. Now at each wheel (all four) I get bubbles during two pedal strokes. Then on the third stroke only fluid so you think you've got it all. Same thing at next wheel and next wheel. However repeating a wheel already done, same thing, bubbles for two strokes. I've gone around the car many times always the same result, air bubbles on two strokes then clear fluid. Have gone through 2 ½ qts. of fluid. I've successfully bled brakes many times in the past so am careful to not open bleeder screw until my wife is pushing down on the pedal and I always close the bleeder screw before she releases the pedal. She's a good sport and has always helped me do this in the past but after so many tries this time I'm sure she's not too keen on having another go at it! This will probably cost me something.
Here’s the “BRAKE FLUID AIR BLEEDING” section from Mazda CX-5 workshop manual. A couple of things here:

• Begin air bleeding with the brake caliper that is furthest from the master cylinder.
So the bleeding sequence is RR、LR、RF、LF.

• If the air bleed from the left/right rear calipers is insufficient, air bleeding can implemented quickly by operating/releasing the electric parking brake several times while performing the work in Steps 7 and 8.
This’s something new to me for brake fluid bleeding with EPB.

4871AFFB-E2E0-4DB7-A45B-727CD6895198.png

4A7FED22-2C8E-4564-A7C8-938A316D72D0.png

30961C32-8718-4FFD-AEF2-879D0B7F59CF.png
 
Last edited:
Thanks for the tip about working the E-Brake. I'll give that a try. This is my first car with electric parking brake which I like but like most new gadgets is another thing to go wrong or affect other procedures that we have been familiar with.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Thanks for the tip about working the E-Brake. I'll give that a try. This is my first car with electric parking brake which I like but like most new gadgets is another thing to go wrong or affect other procedures that we have been familiar with.
I have never done the brake job with an EPB also. My rear calipers (so as the rear brake pads and rotors) were replaced under warranty (a week before 36 months) when I presented the TSB to my Mazda dealer. Please let us know how does it go after you tried the “operating / releasing the electric parking brake several times” procedure.

Did you do RR、LR、RF、LF bleeding sequence?
 
OK, thanks for your advice. I think all is good now but I have to 'fess up" here. There was operator error on my part. Thought I was so smart using a piece of plastic tubing to catch the brake fluid being bled off. I used to just cycle the bleeder screws, watch & listen for air and catch any fluid in a rag. This time I thought I would be neater and use tubing to catch the fluid being bled off into a plastic container. It finally dawned on me that with the end of the tubing immersed in the fluid the bubbles I was seeing when the pedal was pressed were just from the air trapped in the tubing. Duh. Well, I did want to change the fluid completely after 118K miles so my extra bleeding accomplished that. At least that's my rationalization. Brakes seem to work fine now but with the engine running and the car not moving I can bottom the pedal on its stop. Is this normal? I probably never tried this before changing the calipers so it may be like it was before, just not sure.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Brakes seem to work fine now but with the engine running and the car not moving I can bottom the pedal on its stop. Is this normal? I probably never tried this before changing the calipers so it may be like it was before, just not sure.
Unfortunately this definitely is not normal. This means you have some internal leak within the brake master cylinder.
 
:
'16 Mazda CX-5 GT
Thought to add to this thread rather than starting anew... have a 2016.5 CX5 that I have 31,500km on and have been hearing some brake noise from the rear. Inspected brakes front and rear and fronts still have life left, but rears need replacing and the outer pad on the left caliper is down to metal (hence the noise heard).

Ordered a full set of Powerstop rotors and pads so am sorted for that, but my questions are on the apparently relevant TSB (R052/16C): by my VIN, I believe I fall within the range affected but my calipers do not have a lot # stamped on them to indicate whether or not they have been modified. So, from my reading of the TSB I would need to replace the affected side (i.e. left caliper), the local dealer I bought the car from no longer sells Mazda so are little help and the next closest is some ten hours drive away.

From the TSB they give the part # for the replacement caliper needed, but would a OE-equivelant caliper suffice? Rotors and pads have cost me some $460 all around and I would like to keep my costs down if possible and would be doing the work myself. Any thoughts would be appreciated and thank you to Anchorman and yrwei52 for the posting of the TSB's and other information.

Brad
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Thought to add to this thread rather than starting anew... have a 2016.5 CX5 that I have 31,500km on and have been hearing some brake noise from the rear. Inspected brakes front and rear and fronts still have life left, but rears need replacing and the outer pad on the left caliper is down to metal (hence the noise heard).

Ordered a full set of Powerstop rotors and pads so am sorted for that, but my questions are on the apparently relevant TSB (R052/16C): by my VIN, I believe I fall within the range affected but my calipers do not have a lot # stamped on them to indicate whether or not they have been modified. So, from my reading of the TSB I would need to replace the affected side (i.e. left caliper), the local dealer I bought the car from no longer sells Mazda so are little help and the next closest is some ten hours drive away.

From the TSB they give the part # for the replacement caliper needed, but would a OE-equivelant caliper suffice? Rotors and pads have cost me some $460 all around and I would like to keep my costs down if possible and would be doing the work myself. Any thoughts would be appreciated and thank you to Anchorman and yrwei52 for the posting of the TSB's and other information.

Brad
My opinion is you want to replace both rear calipers with revised OEM calipers. You replace everything in a pair on the same axle for brakes, especially brakes are important safety item. Your right rear caliper will be getting worse, and may lock the tire in the worst case scenario.

I’d get OEM rear pads and rotors for $200, and use $260 to get a pair of revised rear calipers and seals. I don’t even believe you can get aftermarket rear calipers with EPB.
 
:
'16 Mazda CX-5 GT
My opinion is you want to replace both rear calipers with revised OEM calipers. You replace everything in a pair on the same axle for brakes, especially brakes are important safety item. Your right rear caliper will be getting worse, and may lock the tire in the worst case scenario.

I’d get OEM rear pads and rotors for $200, and use $260 to get a pair of revised rear calipers and seals. I don’t even believe you can get aftermarket rear calipers with EPB.
Thank you very much for the advice...
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
⋯ have a 2016.5 CX5 that I have 31,500km on and have been hearing some brake noise from the rear.
BTW, since you can’t see the lot number on rear calipers, what is the manufacture date of your 2016.5 CX-5?

34AF2552-1951-4293-BC45-FDA905F2FCAF.jpeg
 

Latest posts