Hello all,

Just wanted to know if anyone is having issues with their rear brakes? My car just hit 20K miles with the majority of it being city miles. My rear brakes sound like the calipers are sticking really bad and the dealership is trying to say it's the brakes. They need replacement, which I think is BS. They also said the Brake Fluid needs to be changed. I've had plenty of new cars and never had to do this at 20K miles. I seen others post online saying the same thing. Please help!

 

It is not just Mazda- All of the newer cars have the same issues with rear brakes, not only are they thinner then the front. They do more then just stop the car they are involved with traction control etc. but your driving conditions did not help-City driving is constant stops. If you did 20K mostly highway you would be fine.

As far as the brake fluid, I have heard around the three year mark is the time but I have had cars for ten plus years that I never changed it and never had a problem.

 

The only thing mechanically that I don't like on the CX-5 is the brakes.
I didn't like them when drove one but still I purchased one as I liked everything else.
I normally upgrade to performance brake system (pads/rotors and calipers if need be) on most of my vehicles and will do so with the CX-5 when the time comes
Just adding better pads will improve them or step up to pads/rotors and using the OEM calipers should be more than enough.
It's not all that much money for performance parts (no I'm not talking racing/track type) and it's pretty easy to do for even the minimally mechanically inclined.

 

Keep in mind that all city driving is considered "severe" duty use. My rear brakes had to be replaced 3 days after I bought my '16. It had sat a while and the thin rotors rusted to the point it ate the shoes. It was a CPO car so the dealer took care of it. Down the road, the front, and later the rear, brakes were upgraded to vented rotors.

As to flushing fluid, you SHOULD do it every three years or so, but most people don't. DOT 3 and 4 brake fluid is hygroscopic and absorbs moisture from the atmosphere. This will cause the calipers to rust inside and stick. Since brakes are the MOST important system on the car, I don't cheap out. An engine failure, you just sit. A brake failure, your little bottom will look like a bunny rabbits nose.

 

I am sorry to hear that your having problems with brakes at 20k. Car does have 3 year warranty, try calling Head Office.

As a DIYer, i understand you have to for 2022 model put car into Brake Service mode. However, there are very few ODBC devices that put the brakes into service mode. The dealer can do this off course.
Has anyone found a way to do this when changing brakes on cx5 2022 model?
This is required to back off the brake pads as not like other cars.
thank you

 

Not to challenge you but I believe there are test strips for the brake fluid to see when it needs to be changed. I took my 2011 Tacoma to an indie shop several years ago when it was about 5yrs old. I asked to have the brake fluid changed. They took it back and then came back out and said my fluid tested fine. No need to change it. I have a personal friend who is a mechanic at a VW/Audi/Porsche dealer. He also tells me there is not really a time/mileage requirement. Just test the fluid and change it when it fails the test.

That being said I grew up with the 2-3yr intervals for brake fluid, coolant etc. It seems fluids last longer these days (or the intervals have changed).

 

I can't speak for Mazda USA, but I can for Mazda Australia, Brake fluid is replaced every 40,000kms ( 24,000 miles ) or 24 months

 

1: Brake fluid service interval is 2 years/20k miles. Why? Brake fluid is hydroscopic, so over time and usage it breaks down into water, about 2 % per year, so that means you have about 4% water in your brake lines, which can lead to soft brake feel in the short term, and rusted lines and all sort of issues in the long term. Your brakes generate several hundred degrees of heat so those water (H2O) molecules are separated into H1 and O2 molecules, and these small amounts of air add up to soft brakes and other issues.

2: the rear brakes wear out faster the the front because of the ABS logic of the brake system. Under soft braking, the ABS system engages the rear brakes, instead of the front. This reduces body roll and results in a smoother ride. Under hard braking, the front brakes absorb ~70% of the braking of the braking force. Under soft braking, the force is re-directed to the rear, depending on speed and applied braking force from the pedal.

In my experience, most modern Mazdas, regardless of model, show 2mm less break pad on the rear relative to the front. Meaning, if your front brakes are at 6mm, your rears are at 4mm. If your fronts are 4mm, your rears are 2mm.

Regardless, you should change them at 3mm and have your fluid changed every 2 years, or 20k.

 

Service mode is easy, but there are a few variations on how engages/disengages. It does not require MDS access.

Engine off, Ignition on. Press and hold gas pedal, push and hold (sometimes pull and hold) the E-brake button, while also pressing the Start button to cycle through off-acc-ign on three times. You will hear the rear electric calipers disengaging (for about 5 seconds of a screwing noise) and the yellow Parking Brake light is illuminated on the dash. Sometimes you have to press/pull and hold the button, then gas pedal down, then press the Start button three times. It all depends on the model. The concept is the same.

Only then is it safe to push the rear caliper pistons back into place. Yes they push in, not screw in. Some models require the caliper piston to be precisely aligned to a notch on the in-board brake pad...failure of this alignment will result in numerous DTC codes and potentially damage/failure of the EPB (Electric parking Brake) itself. Never screw in a Mazda EPB. Only manual calipers must be screwed, FYI.

The procedure is the same for taking it out of Brake Service Mode, but reverse. if you pushed the button, now you pull it, and visa versa. You will hear the same screwing sound as before, much much quicker, and the yellow dash light will turn off.

Failure to activate Brake Service mode when replacing the rear brakes will result in failure the rear calipers and require replacement, 100% no ifs ands or buts.

Just take it to the dealer and let them fix it right the first time.

 

You can also try this if you want to know for sure your fluid needs changing: https://www.familyhandyman.com/proje...k-brake-fluid/ and (Pretty corny video BTW, but good info)