Light Clunk from Left Front at Start of Drive

[obnxs15]

I have a 2020 CX5 GT GT (dumb trim level naming)

I’m not sure if the two are related, but often (not always though) there is a light clunk that comes from the front left of my CX5 when applying the brakes at the start of driving and then it doesn’t happen again until it rests for a while.

In addition, I seem to have quite variable brake pedal pressure. Sometimes it’s nice and firm and other times it’s so soft I feel like I’m going to put the pedal all the way to the floor. It can vary all on one trip or just be different from trip to trip.

I’m not sure if any of this is related to the auto hold/automatic braking system or something else? Is there a vacuum pump or something in that area of the car that helps with the various auto braking systems? If I’m sitting in a drive thru for a long time with the hold function on I sometimes get a weird squeak inside the cabin like pressure was release from a valve.

 

[erhayes]

I suspect that the noise is the brake pads shifting in the mounts. Ed

 

[jadmt]

I thought there was a service bulletin on this..

 

[HyFlyer]

... there is a light clunk that comes from the front left of my CX5 when applying the brakes at the start of driving ...

I agree with Ed ... Likely brake pad shifting in the bracket. Mine will do it on first brake application after backing.

... In addition, I seem to have quite variable brake pedal pressure. Sometimes it’s nice and firm and other times it’s so soft I feel like I’m going to put the pedal all the way to the floor. It can vary all on one trip or just be different from trip to trip. ...

Yeah, car "safety" systems. If the radar cruise is already applying brakes and you brake manually on top of it, the brakes are super sensitive. Or, hit the brakes quick or hard and the car adds to it. Some sort of "braking assist" thing assuming you aren't hitting the brakes hard enough. A feature I dislike.

I'd like my brake feel to be the same all the time please and thank you very much Mazda. I'm not much a fan of ANY "driver assist" tech myself.

 

[GrampaSlade]

If it were me, I would pull the tire off and have a look at all the brake parts.