Thanks for believing me (unlike some others here )

The original dealer, who did the clutch pressure recall, and messed up the brakes was:

Rogers Auto Group
2720 S Michigan Ave,
Chicago, IL

After talking with friends, I brought it back to where I bought it from and they fixed it:

Apple Chevy
8585 W 159th
Tinley Park, IL

 

Oh, and the service writer was actually really cool with me at Apple, even though I took it as him thinking I was nuts. He was a bit confused when I was trying to explain it, but he said any customer concern would be taken seriously and looked into. I felt like nit pick'n for a 1/4 sec delay. But, with the brake peddle, that can be a LONG time in some situations. Also made parallel parking a pain, cause there was also a 1/4 sec delay on releasing the brakes.

 

T-Pole, can you be a little more descriptive of your issue. I don't remember any braking change immediately following my trans reprogram. But...I have noticed since I have had to make a couple of panic type stops, that the brakes seem more like they are grabbing. And in thinking about this, maybe there is a delay or extra distance I am having to push the pedal before they start to brake. I thought I might have damaged something in the stops but did not lock them down to a stop...just hit them hard and then metered the amount I needed to actually slow. But since then, pulling into the garage or to a complete stop, they seem to be a bit grabby. Does any of this sound similar? The brake reprogram for the trans reprogram is that complicated fjungman that only certain shops can do it? Makes me a bit nervous since I am at a small dealership. Not doubting there capability...just had one of them tell me he didn't remember everything he learned in hybrid training. I don't doubt that because you need a service manual and all the bulletins to do anything to these vehicles but to admit that to the customer...makes me wonder if I might have an issue I just wasn't aware of. So T-Pole, did you notice this immediately after you drove from the shop?

 

I didn't notice it on the drive home from the dealer. Pulling into my garage that night though, (kinda a tight fit) I was 'inching' forward, and the brakes just weren't right. "grabby" might be a good word for it, but try this:

From a stop, roll forward about and inch (foot totally off the brake pedal) and try to stop IMMEDIATELY. I had about a 1/4 sec delay before ANYTHING would happen. Then, with the peddle depressed at a stop, side step the brake, and see if it rolls immediately. I also had a 1/4 sec delay before the transmission would kick in/brakes would release.

This only occurred, ahh, hard to explain. OK, if I was on the brakes, like setting them, they'd act normally after that 1/4 sec delay. It was only the transition period between no brakes applied/applying brakes, or visa versa.

So, driving normally, you'd hardly notice it. But trying to parallel park, or inch forward, it was pretty apparent.

Again, I haven't picked up the truck yet. I should have it tomorrow night, or the next day. I'll update if the problem is actually fixed, but the dealer says it is.

Also, this is the only problem I've had in about 15 months of owning it, and about 19,000 miles.

 

I have expereinced somthing similar in my new 2010 Tahoe when parking in my tight steep downslop garage at home.

when I hit the breaks trying to manoeuver to park my Tahoe, the car sway a lot back and forth everytime I hit the pedal, it is not very comfortable.
Is that what you are experiencing guys?

As if the brake pedal is not sensetive enough to stop right away, when you hit the pedal, your foot has to travel further down to stop, and it is hard to fine tune your foot on the pedal to stop it without the back and forth swaying like a normal car.
I thought that was due to weight of the vehicle and not the braking system??

This could be due to the hybrid electrical/ hydraulic braking system.

any feed back is appreciated

 

Guys: at low speeds the brakes are all hydraulic. < 7 mph. As T-Pole has experienced a good pedal sensor cal at the dealership can make a big difference.

 

Marty, is the pedal sensor used to activate the power-assist below 7mph?

 

Not by itself.

Power assist is always available, it just depends on what the specific hybrid system needs to do in any given situation. Since the braking in most hybrids is a "blended" process of electricity generation and hydraulics, correct sensor calibration is absolutly important. Any hybrid. That said the sensor is important ALL the time.

The reason I put the 7 mph up was that is the speed that I can no longer hear the motor "MAG" whine respond to my brake pedal changes. (It is probably NOT absolute 7) When I use the pedal to make "funny" motor noises my kids refer to this as "it is speaking whale". Many 2 Mode drivers have probably noticed the motor noise when slowing to a stop with engine off or on. Engine off it is just easier for me (old guy) to hear. A couple of times I have been tricked and thought I heard a siren.

Below 7 mph I can't get the vehicle to speak "whale". So I infer that my Re-gen has stopped and the vehicle has switched over to conventional hydraulic.

Many vehicles with ABS turn off ABS at low speeds < 5 mph. These 2 Modes have ABS, and some sort of stability control, so if the sensor is off, it stands to reason that the brake system can not properly do its job of conventional, ABS, or blended hybrid braking.

So on any dealer updating doing this step right is important.

 

When I first got the Silverado 4x4 Hybrid, it seemed to be as smooth as glass. But now I seem to see that metering brake pressure as you do pulling into the garage or a parking place, it is too grabby. It drags you to a stop, you release, it rolls to quickly, you brake to a stop, etc. I just can't remember it doing that at first. I thought my couple of panic stops might have glazed the discs and made them sticky. I truly don't remember these symtoms after the transmission recall reprogram. I think I might just take it in and spec sticky, grabbing brakes a slow creep speed and see where it gets me. But will wait for a few comments about that first...be next week anyway. Thanks for all the consideration on this. Didn't think I had a problem but you never know. Bet they can fix it though.

 

I can't go drive mine and check (it is in Vegas), but when it gets back I'll recheck. I drove it last week and it was perfect, but I wasn't feeling for a problem.