I recently posted about some concerns I have regarding my new HCH2's brake system. Just a refresher: I have a sample size of three: my own new '08 with ~900 miles on it, my buddy's new '08 with about 1000 miles on it, and an '06 pool car at work with 22K miles on it.
Issue #1: Weird rear crunching noise if you press the brake pedal all the way to the floor when stopped. It crunches when pressing, then 'un-crunches' when I release the pedal. It sounds like the rear right drum brake is making the noise. It doesn't happen during normal driving, fortunately. I took it in to the dealer last week and got the typical 'That's normal for drum brakes' BS. (Yeah, right, so why do the other two cars not do it, or any other car I've ever owned, for that matter??) Strangely, after driving in some very heavy rain (and deep puddles), it seemed to stop making the sound entirely for a day or so. I also noticed that the sound is much less severe when the car is dead cold. I plan to take the car to another dealer next week.
Issue #2: Minor 'whirring' pump noise after a lot of brake usage. I am no longer concerned about this one, as my buddy's '08 makes the exact same noises. I just find it interesting that the '06 doesn't make the noise AT ALL. Maybe they changed pump suppliers?
Issue #3: If I press the brake pedal to the floor while stopped, (to the point after you feel that 'click' of the pedal), I hear three quick 'pshhuuuh' sounds. It's exactly the sound of air pressure being released, like a semi truck's air brakes. Could someone else please check and tell me if their car also does this? I never tried it on the '06, but my friend's car does NOT do it, so it concerns me a bit. His car also seems to have a smoother transition during braking when the engine does the Auto Stop routine, so I wonder if this might be related.
That's if for now. I love the car, but am hoping to resolve these minor concerns soon.
To expand on Issue #1, I also have now noticed that I can get the exact same noise if I pull the manual parking brake. It happens even when the engine is off.
lawndart: Can you test for Issue #3? I'm just curious if it's a normal thing. While stopped with the engine in Auto Stop mode, push the pedal to the floor (past that 'click' feeling) and hold it. In about three seconds, you'll get a series of 'pushh' noises. Or, do you?
I tried to see if your issue issue #3 was something that I could reproduce. I didn't really notice anything out of the ordinary when the car went into AS. The brakes didn't make any additional noise after I was at a full stop and the pedal was pressed all the way down.
I have had my 2007 for over a year and 13+k now, and yesterday was the first time I noticed your issue #2!
We were driving down a mountain and I had been riding the brakes for a while when it started happening. When I let off the brakes, the noise would continue for another 5-15 seconds before slowly fading out. I'd describe it as a whining/whirring/rubbing sound -- almost like there are parts rubbing up against each other over and over.
Has anyone else had this issue and definitively had it diagnosed?
I have an 07 with 36000 miles. I have observed all three of these issues. I think they are all normal for this car. I also had the jerky auto stop routine going on. I thought that was normal but a recent software update lowers the clutch pressure (I think) and the auto stop transition is silky smooth now.(At least for the last 3000 miles anyways). The whirring and psh noises I attributed to servos and pumps doing operating during braking and autostop.