2019 CX-9 Weak Braking Power

Hi all, I have a 2019 Signature that I bought this past March. Due to C, I only have 2600km on the vehicle. I’ve experienced weak braking power, which is most noticeable at higher speeds (80km/hr and up). I have to pump the brake pedal harder than I’m used to Fully stop or stop enough to make a turn. I’ve never experienced this in other vehicles I’ve owned and driven. Wondering if this is a characteristic of this model or if something might be wrong with my vehicle? I’m going to get the dealership to check it out but wanted to do my own research before I go so that I don’t get jerked around by the dealer. Any thoughts or similar experiences? Anything I can check on my own?
 

sm1ke

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'18 CX-9 Signature
Check brake fluid to make sure you aren't running low and that it's in good condition. Did it gradually get worse in your regular driving, or are you just noticing it now because you're braking at higher speeds?
 
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Check brake fluid to make sure you aren't running low and that it's in good condition. Did it gradually get worse in your regular driving, or are you just noticing it now because you're braking at higher speeds?
Ok will do that. I’ve noticed it since buying it but didn’t notice till a week or so later once I took it on the highway/ higher speeds etc. So I’d say it’s been there since the beginning.
 
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Mazda CX-9 Grand Touring 2016
That's something unique to your car. There can be several reasons for what you describe. Be sure the service writer puts the problem on the repair order, not just his guess at how to fix it. You probably do not need a brake job...replace a lot of expensive parts...as if you had a lot of miles and worn out brakes. You certainly do need the tech to find and fix the problem of the weak brakes. It might be a defective power booster, or maybe something else. If there is low brake fluid, the reason for the low fluid must be found and fixed.
 
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'16 CX-9, '19 GTI
My wife and I both felt that way about our 2016 from the time we bought it. More brake pedal pressure required than for our other cars. It could be the OEM tires having poor grip. I just got new tires, but they're not broken in yet so it's too early to say whether they brake better. It could also air in your brake line. When I bled the brakes last year, I got a lot of bubbles coming out of one of the front brake lines.
 
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Mazda CX-9 Grand Touring 2016
Brakes stop the wheels from rotating. Tires stop the car. Brakes that need a hard push on the pedal for ordinary braking has nothing to do with the tires. If the push on the brake pedal locked the wheels and the tires slide, then it's the tires not gripping. (A tv news shot a few winters ago interviewed a young driver who crashed into a light post in a snowy parking lot complaining about the brakes in the snow. Uh-uh. The brakes worked fine. The tires didn't grip.)

Air in the braking system gives a spongy pedal feel. Pumping the pedal several times will finally give the firm pedal feel.

My 2016 CX9 has always had brakes that feel completely normal and do the job fine.
 
My wife and I both felt that way about our 2016 from the time we bought it. More brake pedal pressure required than for our other cars. It could be the OEM tires having poor grip. I just got new tires, but they're not broken in yet so it's too early to say whether they brake better. It could also air in your brake line. When I bled the brakes last year, I got a lot of bubbles coming out of one of the front brake lines.
So I feel like my braking effort to stopping power has improved but still “weaker” compared to my wife’s 2016 Toyota Sienna. Do you feel like yours has improved? I wouldn’t say my brakes feel spongy, I just have to push harder to get to a full stop.
 
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'16 CX-9, '19 GTI
Brakes that need a hard push on the pedal for ordinary braking has nothing to do with the tires.

Is it that straightforward? If the tires have a poor coefficient of friction, I would think more brake pedal force would be required to achieve the same stopping power as a tire with a higher coefficient of friction.

So I feel like my braking effort to stopping power has improved but still “weaker” compared to my wife’s 2016 Toyota Sienna. Do you feel like yours has improved? I wouldn’t say my brakes feel spongy, I just have to push harder to get to a full stop.

It seems better after having flushed the brake fluid (and gotten rid of some air in the line) and with the new tires, but it's really hard to assess because I don't have a consistent frame of reference. One of our other cars has been sold and the third car has had lots of its own brake work done. So maybe it's better or maybe we're just used to it? In any case, we no longer notice that the amount of brake pedal pressure required for the CX-9 is greater than expected.
 
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Mazda CX-9 Grand Touring 2016
Tires with a poor coefficient of friction will skid when better tires will grip. The better tires can put more braking pedal force to use before skidding.
 
On my 17 signature i feel too less breaking then my other cars but not terible. When my brakes go i will install ebs brakes and vented rotors also get a wider break line.
 
Like PTGuy said. You won’t feel the difference between tires until the tires start slipping (or in this case the ABS kicks in). Your car will brake the same with both tires but the grippier tire will be able to brake harder before the car start slipping.
 
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Mazda CX-9 Grand Touring 2016
EBC, PowerStop, and Centric (maybe others) all offer upgrade kits for our cars. I know that stainless braid brake hoses are a popular thing, but I've had one fail, and I've never had a stock brake hose fail except due to very old age. The braided brake hose that failed me had a teflon inner tube. Teflon is not good where it gets flexed frequently...EPDM is a much better choice of materials for brake hoses. Hydraulic hoses, including brake hoses, have an inner tube that must be compatible with the fluid, a wound or braided reinforcing layer to hold the pressure, and possibly an outer tube to protect the reinforcing layer.

In any case, this has nothing to do with the original complaint about greater than average pedal force needed for average braking.
 
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