Clunking noise when braking...

[Emgee]

Hi All

I've noticed a clunking noise when I apply the brake to the car the first few times after it has sat for a while. At this time, I don't know how long the car needs to 'rest' before it occurs.

It happens only the first few times the brakes are applied and then for the remainder of the drive all is good.

Anyone here experience this in their CX-7 or other vehicle? If so, were you able to determine what the cause was or if this should be a concern? I'll be going in for an oil change in a couple weeks so I'll mention it then to the service dept.

I read some other post by an MPV owner, with similar symptoms, who mentioned they had their brake calipers replaced and the noise went away.

Forgot to add:

Driving a 2007 CX-7 AWD GT :)

Thanks.

[BOOSTR]

Could just be the Mazda ABS system, I get that sometimes in my MSP. But I know my calipers are fine.

[erhayes]

I get a clicking noise ( 1/2 second or so) first time I applie brakes. I consider it normal as my ABS is going through a safety cycle. You say a Clunking noise which sounds different to me. I would first check all wheel lugs for tightness. Is it possible you get some surface rust on the rotors when it sit for a period of time?

[Shaz]

There is a TSB for that guys

FRONT BRAKES SQUEAK WHEN APPLYING BRAKES (http://www.finishlineperformance.com/pdf/cx-9/bulletin/04-001-08-1869.pdf)

REAR BRAKES SQUEAK IN COLD, DAMP WEATHER (http://www.finishlineperformance.com/pdf/cx7/bulletin/04-010-06-1708.pdf)

[Emgee]

Thanks for the feedback so far guys...

It's not a squeak noise, it's a ker-clunk-clunk noise (lower frequency).

It's not the clicking noise I hear when the car first starts up and you get that initial ABS clicking.

I'll check the wheel lug nuts to be sure and I'll look at the rotors for rust before heading out next time.

It almost seems like something is reseating/shifting itself because after the first few times I stop the car it goes away. Once before I tried braking hard to see if the clunking would return after it subsided but it remains silent for the duration of the drive. Just seems, so far, to occur after the car has sat for a while.

It's also starting to, finally, warm up here so I'll see if it goes away with warmer temperatures. I get the distinct impression that Mazda did not evaluate this car in cold weather... so many noises when it gets cold. :)

Thanks!

[erhayes]

Do you use the parking brake? I wonder if the shoes are rubbing slightly and then relelease fully when you apply the regular brakes.

[chris41]

Both our CX-7's do that.....stops after a couple of braking events.

http://www.finishlineperformance.com/pdf/cx7/bulletin/04-010-06-1708.pdf

But I wouldn't describe it as a squeal.......so.....

http://www.finishlineperformance.com/pdf/cx7/bulletin/04-004-08-1897.pdf

You'll notice the replacement pads for both TSB's are the same. Personally, it doesn't bother me as I just expect it in the morning during the first times I apply the brakes.

[MZ CX-7 AB]

My CX-7 is doing the same. I had it looked at by my dealer. They said the front brake pad shims were worn out. So they have ordered the parts for the front brake squeal-TSB. They are going to replace the front pads along with the new update shims, and perform a brake service, all under warranty.

I'll let everyone know after the parts are replaced.

[jmhumr]

I get the clunking noise too. I've had it most the life of my CX-7. It always happens first time I apply the breaks after moving out of park. Sounds like a can of beans clunking against the side of something. I always assumed it was associated with that "clunk when moving out of park" Mazda says is normal.

[erhayes]

My Subaru used to "clunk" the first time I used the brakes every morning. I found it was the pads shifting in the calipers. I measured the pad and caliper and found 0.011 inch difference. The clunking was still going on through two set of pads when I sold the car at 127,000 miles with excellent braking.

[Emgee]

Thanks for all the feedback and links guys.

Since others are hearing similar noise under similar conditions then I'm satisfied that it is the 'norm' for our CX-7s.

Next service I'll mention it to the service department and see if they'll do anything under warranty about it.

It's an bothersome noise, but at least now I can ignore it without thinking much more about it. :)

[Shaz]

Could it be this TSB. I'm still having this symptom and it doesn't really bother me since it only occurs when I shift from P to R. I'll have my dealership do this on my next visit

TSB: CLUNKING NOISE WHEN SHIFTING FROM P TO R (http://www.mstore2000.com/PDF_Files/03-004-06-1643.pdf)

[MZ CX-7 AB]

Okay so I had the front brake pads replaced as per the TSB and no more noise from the brakes. My dealer covered everything under warranty, including the front brake service. We'll see after driving it a while if the noise returns. :)

[Shaz]

I'm actually gonna do this TSB replacement of the brake pads for both front and rear but I will wait close to the time they're almost wearing out hehehe. So the question is, at what mileage do we usually replace the brake pads, front and rear, for AWD vehicles?

[cjones28]

My CX7 has the same problem clunking on braking EVERY time. It's become more prevalent, used to be occasional but now it's every time I brake. My car never had this problem when it was new and my dealer keeps telling me "it's normal ... it's ABS brakes". I've had cars with ABS before and never had this problem. I don't believe it is normal, given that my car was never like this when I picked it up out of the showroom, there's something definitely wrong and my dealer is just stalling me until the warranty runs out.

[MZ CX-7 AB]

cjones28, have you tried another Mazda dealer? Let them know you know of others who have had this problem and the TSB-replacing the pads with the new updated shims-has helped cure the problem.

[Emgee]

Hey Guys

Turns out, hopefully, that the klunking I'm hearing when braking is from the front sway bar bushings. The 7 is going in tomorrow to have them replaced. The car has also be clunking when turning (at low speeds) and going over speed bumps at low speeds.

Hopefully they do the trick.

I'll post the results after I get the car back.

[jmhumr]

Hey Guys

Turns out, hopefully, that the klunking I'm hearing when braking is from the front sway bar bushings. The 7 is going in tomorrow to have them replaced. The car has also be clunking when turning (at low speeds) and going over speed bumps at low speeds.

Hopefully they do the trick.

I'll post the results after I get the car back.

Let me know how that goes!

For about the last 6 months I've notice a "scrunching" noise (hard to describe) when turning and going over bumps at low speed. I just assumed it was due to "Mazda's notoriously loud cold weather shocks." Well it's May and the noise persists, so I'm guessing I have the same problem as you.

[Emgee]

I've now had the vehicle for a week with the new front sway bar bushings and...

The clunking is reduced but not totally gone. Without testing a minty-new CX7 I can't say whether the noises I hear now are just the norm or not.

@jmhumr

The scrunching noise going over speed bumps at low speed, which I had, are now pretty much gone.

I still get a knock or clunk when turning slowly, but not as frequently.

Overall there is improvement.

[TRXSandRacer02]

it is not an abs issue it is the shim clips on the caliper mount where the pads sit. Mazada can warranty replace them up to 1 yr 12k miles. Otherwise deal with it or replace your brake pad shims, PM me and i can get you the updated MAZDA part number. The updated shims are like 12 or 15 dollars from MAZDA

[TRXSandRacer02]

the crunching noise if probably sand and stuff in the rubber isolators of your strut. Clean them really good and watch the noise disapear. Or if under waranty take it to the dealer