2021 CX-9 brakes feel soft?

[redline3104]

So my 2021 CX-9 is the 5th Mazda I’ve owned since 2013 and I noticed the brakes just feel very soft. I feel like I have to apply more pressure then I should, has anyone else experienced this?

My wife drives a CX-5 and she made me drive the other day (after only driving the CX-9 for 2 months) and when I went to apply my foot on the brakes, the car jerked hard as if I was slamming on the brakes. It was like a night and day difference.

 

[sm1ke]

First thing I'd do is check the brake fluid levels under the hood. If it looks ok, I'd take it to the dealer and probably test drive other CX-9s on the lot to see if they feel the same. If yours feels different after test driving the others, ask the dealer to troubleshoot and resolve the issue under warranty.

 

[redline3104]

First thing I'd do is check the brake fluid levels under the hood. If it looks ok, I'd take it to the dealer and probably test drive other CX-9s on the lot to see if they feel the same. If yours feels different after test driving the others, ask the dealer to troubleshoot and resolve the issue under warranty.

I’ve been thinking about doing the same w taking the car to the dealership and testing another cx9 out I just need to find the time to do it, thanks.

 

[youri]

Like Sm1ke said, check brake fluid for safety. If all good you definitely have to compare it with another cx-9 to see if it is really an issue. I wouldn’t expect the brakes on the CX-9 to feel the same as the CX-5. I always have that kind of weird feelings for the first few minutes when i drive one of my car for a while and then jump in my second one.

 

[BrettLevy85]

I have a 2019 CX9 GT and have the same feeling with the brakes feeling spongy / soft. I was thinking of getting a brake flush done thinking maybe air and moisture is in the lines causing it. I only have 15,000 miles on it.

Has anyone put in DOT 4 brake fluid? I know manual says DOT 3 but I know DOT 4 is compatible and could be better.

 

[Orangeman96]

I have the 21 CX-9 and after 1000 miles and they feel fine to me, no extra pressure needed etc.

 

[PTguy]

Spongy brake feel is most likely from air in the system. The brake system can have the air bled out. There is no particular need

 

[PTguy]

Spongy brake feel is most likely from air in the system. The brake system can have the air bled out. There is no particular need

Phone rang before I finished....

No need to flush the brake fluid unless there is a real reasons...more than a few years old resulting in a high moisture content, known contamination, etc. Do get the air bled out.

Has anyone put in DOT 4 brake fluid?

No benefit for this. The higher the DOT number the higher the wet boiling point (defined as containing 3.7% water) of the fluid is. It ranges from DOT3 to DOT4 to un-official DOT4+ to DOT5.1. These are all complex chemical mixtures of polyglycol ether compounds. Borate compounds are added for the increase in wet boiling point, but--the same borate compounds cause the fluid to absorb moisture more readily thus requiring more frequent flushes of the fluid. Brake fluid is intended to absorb moisture from the air and mix it throughout the fluid. The fluid will get moisture. What we don't want is either pockets of water laying in the low points (which might happen with the unsuitable silicone based DOT5 fluid) or so much moisture in solution that the heat of emergency braking causes the water-fluid mixture to flash to steam and the brake pedal uselessly go to the floor.
https://epicbleedsolutions.com/blogs/faq/what-is-meant-by-wet-and-dry-boiling-points-of-brake-fluid#
https://www.bendix.com.au/bendix-news/bendix-high-performance-dot-3-dot-4-brake-fluid-testing

I was in the local NAPA auto parts store buying brake fluid one day. I took it to the counter. The counterman said, "This is synthetic brake fluid. Are you sure you want this?" All brake fluid is synthetic. What they print on the label is just marketing blather.

 

[Jman136]

Just for what it's worth, the brake's on my old 19' CX-5 GTR sucked! That was my biggest complaint about the vehicle. Otherwise, I absolutely loved it!

 

[truckster]

I’ve been thinking about doing the same w taking the car to the dealership and testing another cx9 out I just need to find the time to do it, thanks.

@redline3104 did you ever find a resolution to this? Would like to know if your cx9 had any issues or if yours drove like others on the lot.

 

[racermp]

I also have a 2019 cx-9 and same issue. I've had similar issues in every car I owned, and that's alot. The problem is really related cooling and heating and wear on pads (mainly rear). Cold in morning, then warm once you drive so fluid expands. It's nothing that can really be solved. But you can do this procedure for a few days and it will improve...

Start car...

- Pump brakes hard 5 times

- Hold brake pedal hard down for 5 seconds

You will feel soft sponge then pushing harder a hard spot as you push down the pedal. You will notice the hard spot gets higher and higher each pump. Repeat this 4-5 times each day when first started for the next few days. You will notice how the pedal stops depressing when you hold the brake pedal down hard.

 

[MGMGT16]

I also have a 2019 cx-9 and same issue. I've had similar issues in every car I owned, and that's alot. The problem is really related cooling and heating and wear on pads (mainly rear). Cold in morning, then warm once you drive so fluid expands. It's nothing that can really be solved. But you can do this procedure for a few days and it will improve...

Start car...

- Pump brakes hard 5 times

- Hold brake pedal hard down for 5 seconds

You will feel soft sponge then pushing harder a hard spot as you push down the pedal. You will notice the hard spot gets higher and higher each pump. Repeat this 4-5 times each day when first started for the next few days. You will notice how the pedal stops depressing when you hold the brake pedal down hard.

I am struggling to see how this will solve anything. From what I understand about brakes, your procedure will increase the pressure in the lines a little bit for an unspecified length of time, but fails to treat the actual issue. Just pumping your brakes isn’t going to get air out of the system or fix a leak or bleed the brakes or change the brake fluid. Can you try to help me understand what problem pumping you brakes a few times is supposed to fix?

 

[racermp]

I am struggling to see how this will solve anything. From what I understand about brakes, your procedure will increase the pressure in the lines a little bit for an unspecified length of time, but fails to treat the actual issue. Just pumping your brakes isn’t going to get air out of the system or fix a leak or bleed the brakes or change the brake fluid. Can you try to help me understand what problem pumping you brakes a few times is supposed to fix?

yes this is not a permanent fix, it's temporary, the problem is as the thread title - soft brake feel. it remove the sponginess which pumping reduced pedal travel and brings back the firmness.

i believe it's a design problem in the end of the day that i've seen in many cars. i believe that the fluid pressure in the rear does not increase as much as when the front gets pressure so you get initial friction in the front so u start to feel brakes, pressing more gets more pressure in rear. but hey, this is more testing than all of us will ever do so my solution was a temporary workaround.

 

[racermp]

ok so i ordered ATE dot 5.1 brake fluid. flushed it out. brakes felt like crap. brake pedal was chattering/jittering. pedal was really long travel. really 5hitty

i then change out to Preston dot 4 max synthetic from AutoZone. the pedal is a lot better now than new. the pedal travel is short and it feels like all 4 brakes grab evenly between rear and front axel. it grips really well now and so far the sponginess has not returned.

the way i changed fluid was as follows
pattern: RR, LR, RF, LF
one man bottle bleed (i use 16oz bottle). make sure bottle is higher that caliper. i stuck mine on the shock/strut.
2 32oz bottles of Preston dot 4 max synthetic

1- connect bleed hose to bleed nipple, open bleed bolt 90 degree
2- engine on
3- pump the pedal to the floor until brake light comes on(means fluid is at low mark), then 2 more pumps. last pump hold in, turn off engine and slowly release.
4- fill brake fluid to max mark
5 - repeat step 3
6 - tighten bleed screw, remove bleed pipe and repeat for remaining sides.

 

[DOUGBT]

So my 2021 CX-9 is the 5th Mazda I’ve owned since 2013 and I noticed the brakes just feel very soft. I feel like I have to apply more pressure then I should, has anyone else experienced this?

My wife drives a CX-5 and she made me drive the other day (after only driving the CX-9 for 2 months) and when I went to apply my foot on the brakes, the car jerked hard as if I was slamming on the brakes. It was like a night and day difference.

Have purchased 2019 and 2020 CX9 new and both have same brake feel that your explaining. Kind of makes one more cautious and a little insecure. Have a 2020 Mazda3 with much better brake feel. Have been looking for a solution for some time.