Thumping Brakes? Help!!

rk2112

Member
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Mazda CX-9 GT
In the last few months I have had a braking issue with my 08 GT. When applying the brakes continuously for 2-3 minutes or longer, coming down a long hill steep hill (mostly mountain elevations), I start to get a thumping sound coming from the front end and the steering wheel starts to shake. The harder you press the brake pedal the worse it gets. If you take your foot off the brake it goes away immediately. The brakes seem fine in every other situation other than very steep declines that require you to use the brakes for a longer period of time. I also noticed when it is wet (raining or snowing) after sitting at a traffic light/stop sign when I remove my foot from the brake pedal I hear a "popping sound" almost like the caliper is stuck for a split second (this only happens in wet weather). Of course I took it into my dealer and they said the rotors are not warped and the pads look brand new (44,000 miles), but it just happened again yesterday coming home from mountains. We are leaving for vacation June 5th and I am very concerned, because I have to drive through several mountainous areas on our trip. I am taking it back to the dealership this Tuesday. Anyone else noticed this problem or have any ideas what it could be? Could it be a caliper hanging up? Thanks!!
 
it could be warped rotors anyway

why are you riding on your brakes for so long without engine braking? you'll kill the brakes and endanger yourself in no time!
 
it could be warped rotors anyway

why are you riding on your brakes for so long without engine braking? you'll kill the brakes and endanger yourself in no time!

I would think it was warped rotors it would happen all of the time, plus it is a fairly loud thumping noise. I don't and have never used the engine for braking. If you read most magazines and talk to mechanics that is very tough on the transmission, and brakes are a lot cheaper to replace than your transmission.
 
yeah, till your brakes overheat and you run off the cliff :rolleyes:

you NEED engine braking when you're driving on a mountain... no, it won't hurt your transmission as most of the wear and tear happens during shifting... when you engine brake, you just put it in a lower gear and just leave it there.. it's not like you're constantly doing this

you go ahead and try to drive like this down pikes peak... I guarantee your brakes will heat up and smell so bad that you can barely stop by the time you're halfway down, and the safety people there will keep you from going further... yes, they check each car coming down for brake overheating

there are signs EVERYWHERE in the west telling you to engine brake, for the good reasons I just told you

the brakes are NOT designed to be rode on, plain and simple... whatever you read talks about general driving, on flat roads that engine braking is "bad"... weird things happen when you excessively heat up/abuse the brakes, period
 
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yeah, till your brakes overheat and you run off the cliff :rolleyes:

you NEED engine braking when you're driving on a mountain... no, it won't hurt your transmission as most of the wear and tear happens during shifting... when you engine brake, you just put it in a lower gear and just leave it there.. it's not like you're constantly doing this

you go ahead and try to drive like this down pikes peak... I guarantee your brakes will heat up and smell so bad that you can barely stop by the time you're halfway down, and the safety people there will keep you from going further... yes, they check each car coming down for brake overheating

there are signs EVERYWHERE in the west telling you to engine brake, for the good reasons I just told you

the brakes are NOT designed to be rode on, plain and simple... whatever you read talks about general driving, on flat roads that engine braking is "bad"... weird things happen when you excessively heat up/abuse the brakes, period

I understand to stay in a low gear on those types of mountain elevations. One of the main roads that I have the issue on here in PA is about 2-2.5 miles long and goes from a elevation of 2700ft to a elevation of 1100ft. This is also with just me in the vehicle, and no luggage/cargo.
 
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it doesn't make a difference if you're by yourself or you have it full of stuff in the back... the car is 3500lbs piece of steel, the brakes are NOT designed for being rode on, period
 
Well my last 4-vehicles I didn't need new brakes until 65,000 miles. My dealer said the brakes on the CX-9 look brand new (currently 45,000 miles). I never had this issue driving these same roads with my other cars/suv's I owned, and it was not an issue with the CX-9 either until about 3 months ago.
 
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who knows what is happening when your brakes are overheating like that. I say overheating because riding them for 2 minutes is overheating them. Go a little slower and you should be fine but since you overheated them (seemingly more the once) they maybe Or the rotors) glazed and need to be replaced now.


Stay in a lower gear, go slower and use brakes when you need them.
 
Same here

In the last few months I have had a braking issue with my 08 GT...
The same has happened with my '08 AWD in a lot less than a minute. It happened in May, 2009 and again in July, 2009 - both times descending a mountain with a 1,700 lb. payload. It has also happened numerous times in heavy rain with no payload.
 
Unfortunately the aftermarket for brakes on the 9 is sparse at best. OE rotors are garbage. This was the case with most of the cars I've own this decade. Honda was the worst as the rotor hats on my Accord were completely cracked around the 30K mark with normal driving. Brake upgrades with rotors, pads, fluids, stainless lines are at the top of my list if I intend to keep the vehicle for a few years.
 
The same has happened with my '08 AWD in a lot less than a minute. It happened in May, 2009 and again in July, 2009 - both times descending a mountain with a 1,700 lb. payload. It has also happened numerous times in heavy rain with no payload.

Per the dealer recommendation I had the rotors replaced because of glazing and hot spots (the dealer said the pads look brand new), the issue seems to be gone at least for now. I have to agree that I am not happy with the OE rotors. My father has a CX-7 and has rotor problems also. This is the only vehicle I have owned that I have had this many brake problems. My last three vehicles I didn't have to replace any of the brakes until I hit 65,000+ miles.
 
Unfortunately the aftermarket for brakes on the 9 is sparse at best. OE rotors are garbage. This was the case with most of the cars I've own this decade. Honda was the worst as the rotor hats on my Accord were completely cracked around the 30K mark with normal driving. Brake upgrades with rotors, pads, fluids, stainless lines are at the top of my list if I intend to keep the vehicle for a few years.

Yeah, I have a 07 Honda Accord stick, just had to replace all rotors, pads, and fluid. I went with EBC slotted rotors and Hawk HPS pads with Blue racing fluid. I should have spend the extra money and got Frozen Rotors, some of the best rotors on the market, not very happy with the EBC, but the stock ones were junk! My wife will be driving the Cx-9, but I guess the first thing I will do is change the rotors...once these get messed up that is.
 
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