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Discussion Starter #1 (Edited)
I am wondering if any of you folks have used the attached special procedure while flushing your 3rd Gen. Mazda6's brakes. I would point out the use of the special tool that rotates the rear caliper pistons... and the instruction to tilt-out said rear calipers, use the tool to rotate the piston 180 degree's... then "spiral" the piston down in its bore to fully-stroked.

The reason I ask this, is 'cuz to my way of thinking, in spiralling said pistons in their bores to fully-stroked, you are traversing caliper bore (with the seals) that normally NEVER gets traversed (or actually, you are stroking past caliper bore recessed seals - portions of the piston that never get passed by those seals in normal operation). When it never gets traversed it has the tendency to corrode, or at the least to become rough or to become filled with general grunge. This scores the rubber seals and leads to brake fluid leakage.

When you do this procedure, I wonder if it lessens the life expectancy of the rear calipers, or it initiates a leak that soon will have to be dealt with - likely by caliper replacement (not sure if brake soft-parts are available from Mazda).

I would be interested in hearing folks' take on this.

The Mfr usually knows best, but is this really necessary? Why so?

I think it is prudent to flush the hydraulic system once per 2 years... and I advocate doing it NOT with the two-man method, but rather by using a MityVac or the like at each of the caliper bleed screws, in the proper succession. I say this for exactly the reason I note, above... only related to the master cyl. seals.

Please see attached graphics.
 

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I would like to know where I can buy the special tool for the rear brakes.

And thank you for the PDF file.
 

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A lot of auto parts places will have it and it's a fairly standard-sized setup. Caliper Piston Compressor Brake Tools

The little $12 cube should be all you need, but don't quote me on that :)
The last time the brake pads were replaced, the caliper tool set that is similar to the link you posted didn't fit. In fact, it is almost a "complete" set.

I was at the dealership earlier and I was asking for the special tool they are using but it was misplaced so I wasn't able to get a picture.

Are you referring to this cube?
 

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I did not do that when I flushed the brake fluid a few months ago.

Just looking at the pages you attached, the written instructions talk about pushing the piston back to bleed air out of the system. To me, that indicates this is the procedure to follow when you have air in the system, or you’ve replaced a caliper, or the like. There may be more in the svc manual either before or after what is posted (I don’t remember those pages well enough offhand), but based on what’s posted I would not suppose this is intended as the routine fluid flush procedure.

I understand your concern about damaging seals. To me, that reinforces the idea this is for when a caliper has been replaced and you’re making sure you get rid of all the air in the system.

I’ll note that my car lives in southern AZ, so rust and corrosion are minimal compared with much of the continent.
 

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Are you referring to this cube?
Yup! But I can't confirm if that one in particular will work with our cars because I had one for my wife's 3 and it didn't work - had to custom make one. I didn't have the thing when I did my brakes and ended up using needle nose pliers (y) (would not recommend).
 

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Yup! But I can't confirm if that one in particular will work with our cars because I had one for my wife's 3 and it didn't work - had to custom make one. I didn't have the thing when I did my brakes and ended up using needle nose pliers (y) (would not recommend).

That is exactly what those tech guys from Mazda said, they use needle nose pliers!

I guess what I'll do is ask my friend to make one that is customized for the car. If ever, I'll post it here.

I just don't know when.
 

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Discussion Starter #11 (Edited)
It says to push and rotate the piston (presumably bottoming it in its bore in the caliper)... and then finally to rotate it to the correct notch orientation to allow it to be tilted back into its normal position. What I can't figure out, is how does it come back to a partially retracted position in its bore so as to JUST allow the thickness of the rotor + remaining brake pads to fit-in to the fist caliper? I suppose brake hydraulics, in normal operation would do that, albeit requiring the Master to stroke 'way beyond normal range. U cud use "reverse" pliers though to bring it close to where it should be to lessen the Master issue.
 

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I have a tool that locks into the caliper and rotates and pushes it back in at the same time; I bought it for another vehicle but it works on every rear disc brake vehicle I've tried it on.... and it makes this a very, very easy task.

But do I do this for routine fluid changes? No.
 

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Discussion Starter #16
You mean locks-in to the PISTON (?) and pushes it while rotating it? I am curious as to why the rotation is required, unless it is to free-up the elastomer seals in their grooves, to beneficial effect....???
 

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The parking brake mechanism prohibits retraction of the piston unless it is rotated. It's the way the mechanism in the caliper works, and is how self-adjustment of the parking brake is accomplished -- it's a ratchet mechanism, basically.
 

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I have finally confirmed this so called "maintenance mode" for the electronic parking brake.


Please follow the link, inside the link.


During the maintenance mode, I saw another parking icon lit up and it's besides the check engine light.


I apologize for the blurry picture, I'll get another one later.

You can hear the motor running longer than usual which confirms that you are retracting the pistons. Then you will see the parking icon I just described earlier.

In the link, it says that the pistons now act like the front pistons. That is, you just push it. There's no need to turn it.

I have yet to confirm this.
 

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Yep -- the maintenance mode unlocks the calipers in the back; you should be able to EASILY retract them once you've put them in that mode.
 
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