Robo_geek

The CR-V, which uses the same braking system, has a similar problem, and there is a TSB for this.

The problem is that the rear caliper, especially the passenger rear (due to road salt on the curb-side of the vehicle, in road-salt-use areas), gets corroded. I bet that those who have this issue are those up North where they use road salt?

The brake system is split diagonally, so the left front brake shares it's hydraulic system with the right rear.

The corrosion is causing the caliper to stick, which causes the rear brake(s) to drag. When they drag, they overheat.

If the rear rotors have been overheating, they typically will have what looks like an uneven coating of brake material on them...this is called martensite. This can sometimes be fixed by turning, but normally you just replace the rotor.

When one rear brake overheats, it you would likely boil the fluid, which will reduce the stopping effectiveness on the overheated side, and cause the front brake on the other side to overheat. This is hard to diagnose, since most people don't drop their car off for service when the brakes are at 1000F.

Bleeding the system will fix it temporarily, and upgrading to a better brake fluid would help a bit. Using temperature indicating paint and/or an infrared thermometer could help to confirm the overheat condition for each brake.

jrhjr07

I have for the first time experienced this problem with the rdx as of last night. Of course acurazine pulls through... Called the dealer and I'm having it looked at tonight. They said that break fade is a mechanical problem and SHOULD not be happening. I have only owned the rdx for about 6 months and it has 75xxx miles, but i have not had any other problems... this is very concerning because it is not my daily driver, but my wife and our son. IF this is a mechanical failure that Acura is not addressing - lawsuits are sure to be a big problem.

LittleC982

OMG!!! Last time when they fixed it they said it was the rear passenger side caliper. The whole time I thought it was something with the front driver side cause that's what it felt like. I don't live up North but they do salt the roads here in the winter and I do drive up to the DC area every winter and throughout the year. I'm gonna have to talk to my neighbors that owns a CR-V and see if they've experience a similar issue.

Why is there not a recall on this?? How can Acura continue to put people out in unsafe vehicles? They reason why we bought the car is because my old VW was getting old and unreliable. But I'd rather take unreliable than unsafe.

My car is still at the dealership, been there since 10/15. All we've heard is they can't duplicate the issue now. But not sure why they haven't asked us to pick up the car. Been in contact with customer care and asked how they can continue to put us out in an unsafe vehicle. Response: That is our policy since we can't duplicate the problem. We're getting ready to tap into the lemon law.

Thank you all for letting me vent by the way.

freddieb

I was having this problem you described over the last two weeks. My car has 60 000kms but mostly highway. Today I took it to the dealership and they stated it needs new rear brakes and front ones need servicing. I am not hard on cars and have never had a car that needs brakes at with such little mileage. I agree with the posters that say the OEM brake pads are inferior. I took the car from the dealership (after their ridiculous estimate including 2.5 hours labour for front brake maintenance) and told my Acura mechanic to use EBC brake pads. Hopefully when I pick up my car tommorrow the situation will be rectified.

Thirsty

2012 RDX
I have experienced the same grinding noise but only after certain scenarios. The brake does get slightly mushy during these events, but that is typical of overheating brakes.
It sounds like LittleC982 had a major problem, either due to severely overheating or a stuck caliper causing boiling of the brake fluid on that side of the brake system (right-rear/left-front) thereby causing lack of braking effectiveness. I'm surprised the system didn't respond with a message. As far as the brake lever going down to the floor, if it is veeery slow then there might not be a problem if simply pumping the brakes brings it firm again, otherwise you need a new master cylinder.
My scenario is this....driving around town, I never experience this problem. After an hour drive at high speed (65-75MPH) with almost no braking, I exit onto city streets. Coming to a stop at a light, the last second or two before completely stopping, the grinding noise is heard. This will happen continuously at other lights until I stop the car at my destination and it has time to cool down. Then everything is normal again. This only started happening as my stock tires were worn down below 50%. I figured the tires were heating due to the long drive and transmitting that heat to the wheels/rotors/pads. But, could it be due to the lower tread and/or my tire pressure? After purchasing new tires, I kept them at 2 PSI higher than recommended and did not experience the problem again. While still good tread, I reduced PSI to recommended pressure and I started having the problem again. I will now bring it back up 2 PSI and see what happens as the tires wear more. I'm surprised this would have much of a difference, but I drive the same route many times and only experienced the problem the way I described above. The pads themselves still have 50% life to them, which may also contribute to the issue, but that is still a lot of pad.

Tomtwtwtw

If you're getting any grinding sound at all, check your pads, especially the inner ones on the front. Can't see them without taking the wheel off (unless you can wedge a phone in there and take a great picture). Grinding can be intermittent at first when a pad is about gone, but it will only get worse, and eventually damage the rotor. Generally the only other grinding sound you might get when on the brakes is from the ABS kicking in...but you should be able to tell the difference.

TheWrench116

iTrader: (1)

get new stuff all the way around its an hour long affair to swap in new stuff once the tires are off.

Thirsty

I recently rotated the tires and inner pads were wearing evenly with outer. After I got the grinding noise again this weekend, I checked them again. 50% life left. More than enough. However, they very well might be glazed in some areas. I most likely will swap pads soon. The older Acura rotors were pretty good and could withstand a couple pad changes before replacing. I'm not sure about these though. I cannot believe more people are not complaining.

Tomtwtwtw

Are you able to tell when driving what corner the grind is coming from? Also, have you double-checked wheel bearings and CV joints? If you got a tear in a CV boot and shit's getting up in there, it could also cause noise. I just have never heard a grinding sound from brakes when it's 100% pad-on-rotor contact.

Regarding brakes, I had 1 front pad ready for replacement at 55k miles - driver's inner side was done, passenger inner wasn't far behind, and both outer pads were at ~25% life. Rotors looked great and I did not replace. Closing in on 90k now, still on OEM rears.

Thirsty

It's hard to tell what side the sound comes from. The sound is exactly what metal on rotor would sound like but only in the last 1-2 seconds of stopping. I know that something isn't wrong with the pads/rotors because I checked. About 25K miles ago when I first experienced this, I thought I had a stuck piston and that one pad would be worn but there was nothing wrong. This doesn't always happen even on the same highway/city route I take occasionally. I can drive at city street speeds for a while and it would go away possibly because things cool down. A bad bearing would have that classic growl sound while you are driving which I don't have. CV boots are fine. If it was the booster or master cylinder, then my pads would be prematurely worn but that is not the case either. Definitely an overheating problem caused by heat transferred to rotors. Vehicle stops evenly without pulling or shimmy. I do mostly rural and highway so my pads last a long time but I feel that I had better remove them to examine them at this point.

Tomtwtwtw

Well, if the pads are fine and you think you have a glaze on the rotors, have you done a few panic stops to burn it off? It's just a weird situation, and I'm genuinely curious what comes of it in case some of us experience it in the future.

Thirsty

Just came back from two long highway rides that exited onto city streets and secondary roads. These are the type of roads that get you from light to light getting up to 45-60 MPH then down to zero quickly. This goes for about 5 miles with about 7 lights. At first I babied the brakes, downshifting as much as possible and anticipating a red light by slowing as I approached, then neutral with foot off brake when stopped. I experienced no problem.
On my second long highway leg of the trip, when I exited the highway, I decided to follow the pack from light to light coming down somewhat hard on the brakes at the red lights. It wasn't until I reached a light at a slower speed that I heard the grinding noise in the last 2 seconds of the stop. It did that for another 2 lights until I started downshifting and being light on the brakes. So forget what I said about air pressure or treadwear. Since I wasn't harder on my brakes than anyone else in the pack of cars, the RDX brakes must be the problem. Since I don't get on those secondary roads that have lights every mile of so where you can go from zero to 60MPH to zero quickly, I don't get to experience the problem often.
So, I just received replacement OEM pads to compare when I do my next brake job. I ordered the standard 43022-STK-A01 but received 43022-STK-A02. I can't find anywhere that says the the A02 replaces the A01. I also ordered the standard 45022-SHJ-405 but received 45022-SHJ-415. I saw only one place that the 415 replaces the 405. I would like to know if I received the correct parts now.

QFT

Sorry to kick up an old thread. Anyone had a satisfactory solution to this? I have an 07 and the grinding sound is often there, especially on longer trips. I'm not sure it actually impacts the braking performance (which isn't great anyway IMO), and I've had it with stock pads and EBC pads.

Tomtwtwtw

If you're getting actual grinding, take off your wheels and inspect *both* pads on each wheel. If your sliding pins are not fully lubricated, your inner pad will wear faster than your outer pad. I've seen the inner pad gone while the outer was over 50% before. If you just peek through the wheel and look at the outer pad, you may think all is well when it's not.

Assuming all pads are good, I believe the 2nd most common cause for noise is vibration of the pads against the calipers (this is what the sticky "brake-quiet" stuff is for when swapping pads). That noise is usually a squeal though and is harmless.

CSmoney28