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Basic Vendor- Skid Plates
2007 chevy trailblazer_ls
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Discussion Starter #1
OK, I've seen several posts where people said they've bee coming down to a stop and the brakes would drag, but then they'd restart the vehicle, and everything would be fine.

Here is what happened to me:

Driving home from a friend's house last week on the Interstate. Was following somebody in a car that coasts down faster than the TB, as I was getting toward and on the off-ramp. I was very lightly on and off the brakes 8-10 times during the slow-down. I don't know if it matters, but this off-ramp is curved, but we were going a "normal" speed. It was dry and ~50 degrees F. There was no slippage, of any kind, from the tires.

Toward the bottom of the ramp where it straightens up, I let off the brakes, and the rears stayed applied, feeling like the parking brake was half-applied or something. I hit the brakes again and let off, and they stayed applied. I gassed it and accelerated slightly, and they stayed applied. Having read what other people did, I came to a stop, put it in Park, turned the vehicle off, and back on, and everything was fine again. No brake sticking at all the rest of the way home, or at all since then. There were NO lights, SES, ABS, Stabili-trac, no idiot lights on at all.

I called the dealer about it, and the service guy (From past dealings, seems to be a good guy) looked through the database of TSB's and recalls, and could not find anything about it.

My vehicle, as you can see from my profile, is an '07 5.3L, LS, 4X4, G80, with ~6500 miles on it at the time.

Has this, or something similar happened to you? Please explain the situation, and whether cycling the ignition made it go away or not, as well as any dash lights that were on.

Thanks,
Mike Barton
 

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2003 chevy trailblazer_lt_ext
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51 Posts
Is everyone 100% sure that it is the brakes? Could it be that the torque convertor is not unlocking? It should be unlocking as soon as you are on the breaks. If it's not you'll have hard engine breaking until the TB is down to 5 MPH or less then it will automatically unlock to pervent the engine from dying.
 

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Basic Vendor- Skid Plates
2007 chevy trailblazer_ls
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3,700 Posts
Discussion Starter #3
Is everyone 100% sure that it is the brakes? Could it be that the torque convertor is not unlocking? It should be unlocking as soon as you are on the breaks. If it's not you'll have hard engine breaking until the TB is down to 5 MPH or less then it will automatically unlock to pervent the engine from dying.
It's definately brakes. The engine went back to idle when I was coasting down, and it was hard to accelerate when I sped back up. Plus, I didn't hit the brakes at all until I was completely stopped, and put it in Park. I have a switch to lock up the TCC on my Caprice, and this was DEFINATELY not the same.

Mike
 

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2006 chevy
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245 Posts
Breaks locked up on expressway

I was coming to the end of the expressway (m59/hall rd.) and slowing down at a light I came to a complete stop at the light and when the light turned green I pushed on the gas and car would not move very much I continued to push more on the gas and the car finally started to move! I then started to smell something burning... I got off as soon as I could and when I went to push the brakes it was stuck and wouldn't move!... It seems the brakes locked up I turned off the car and turned it back on and everything was back to normal even had on star run a diagnostics report nothing...

I have almost 18,000 miles on my TBSS and it has a Vector Tune.

Thanks,
Matt
 

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Basic Vendor- Skid Plates
2007 chevy trailblazer_ls
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Discussion Starter #5
Well, since only one person from the old thread has posted their story up, I'll copy them here... From here: http://forums.trailvoy.com/showthread.php?t=28454&highlight=brakes+locked+wtf

I had this very same thing happen to my 2006 ss in jan 07 with 1400 miles. Had it the dealer on several occasions and they could not duplicate the problem. They bled brakes and lots of reprograming and has not happened since. They blamed it on air in the right rear caliper.
This was before i installed my vector tune. Good Luck, Glenn
I have also had this happen to my truck. I have over 20,000 miles and it has happened once.

I was slowing down to turn a corner and when I went to give it gas it kept slowing down. It took a lot of throttle to make the truck move.
I shut the truck off and re-started and everything was OK.

I believe the problem is a glitch in the anti-lock braking system. This is the only thing I can think of that has the power to over ride the braking system and automaticly apply the brakes.

There were no codes on any of the modules & my dealer friends had no clue.

Kirk
I have had the same thing happen to my 2007 TB. It is getting more frequent. At times If I barely touch the brake pedal the car will stop abruptly. It also even slows down going dowm hill with out me even touching the brake pedsal. I have brought it to the dealership 3 times so far and the first time they said the roatra were warped and cut them. The second and third time they told me that there is nothing wrong. I dont even think they put it on the loft and looked. I had an excessive amount of brake dust on my rims and it was still there when I picked up the car. Not even finger smudges from taking the tire off. I think I am be hosed here. Think I am going to try out the lemon law,

Well If anyone has found the problem and a way to fix it I would love to hear it.

THanks
 

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I've never had them lock up while slowing down, but the driver's rear will hold when I take off. It doesn't "hold" me back, just pops a few times and lets loose. Any one heard of this?
:undecided
 

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2005 chevy trailblazer_lt
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Mine does the same thing. slows down fine but holds for a little bit and breaks loose when i give it gas.
 

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2006 chevy trailblazer_lt
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My mechanic (not the dealer) said it is from the rear calipers ceasing. He's seen a few in there for that before.
Rear caliper ceasing would not correct itself with the key cycle as those that experienced this have stated :no:

I would be leaning toward a concern with the Electronic Brake Control Module (EBCM)...the module controls the dynamic rear proportioning which regulates the rear brake pressure. The EBCM could intermittently fail and electronically hold the rear brake apply after releasing the pedal :undecided
 

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2007 chevy trailblazer_lt
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I have had this problem several times and had my TB in at the dealer (who was no help). Then I brought it to my mechanic who I have been using since I can remember and he was unable to find the problem. I was finally able to figure out what the problem was and it was an easy fix. Why I did not think of this from the beginning, I don't know. And I am not sure if this is the cause of your problems. I put in an after market radio (Pioneer AVIC-D2) and had to use a BUS adapter because of the On Star and Bose. After talking to Metra, they told me that although the harness was compatible with 07 TB, it was never tested since it was put in circulation in 06 and was unsure if there were any issues with the device.
It has been 5 months since i put the stock radio back in and I have not had a hick-up with the truck. My guess is there was a communication problem between the data bus and the EBS. Hope that this helps anyone who has been having this problem.
 

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Basic Vendor- Skid Plates
2007 chevy trailblazer_ls
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Discussion Starter #13
I have had this problem several times and had my TB in at the dealer (who was no help). Then I brought it to my mechanic who I have been using since I can remember and he was unable to find the problem. I was finally able to figure out what the problem was and it was an easy fix. Why I did not think of this from the beginning, I don't know. And I am not sure if this is the cause of your problems. I put in an after market radio (Pioneer AVIC-D2) and had to use a BUS adapter because of the On Star and Bose. After talking to Metra, they told me that although the harness was compatible with 07 TB, it was never tested since it was put in circulation in 06 and was unsure if there were any issues with the device.
It has been 5 months since i put the stock radio back in and I have not had a hick-up with the truck. My guess is there was a communication problem between the data bus and the EBS. Hope that this helps anyone who has been having this problem.

Communication issue, probably, but mine is 100% completely stock, radio has never been touched in it, nor has anything else...

I have not had it happen again, because I'm careful not to be on and off the brakes in a trailing fashon, a bunch of times in a row, now... I basically drive around it, which I don't think I should have to do on a brand new, $32k vehicle...

Mike
 

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2008 chevy trailblazer_lt
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I had this happen this weekend in my 2008 TB (~7500 miles).

I didn't even get to move before the brakes locked up. I was moving from my driveway to my garage. Got in, started the truck. Pushed to brake pedal to shift from park, shifted to drive, left off the brake pedal. The truck didn't move but my drive has a slight slope to it, so I didn't think much of it. I gave it a little gas, and the rear end squated a little, but it wouldn't move. I checked the e-brake (which wouldn't have made sense). I pushed the brake pedal to shift to reverse, and noticed that it got hard like pushing the brake pedal when it is off. I wouldn't move in reverse either. I put it back in drive, and give it enough gas to spin the tires, but it wouldn't move. I put it in park, shut it off, turned it back on, put it in gear and pulled it into the garage with no problem.

It felt almost like the booster had lost its vaccuum... Then again, maybe the brakes always have been dragging... that would explain the gas mileage :yes:
 

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2008 gmc envoy_slt
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be aware of another potential problem...

maybe yours will start acting like mine and have the brakes(by themselves) go on while driving straight road, dry pavement....that's fun too....mine (2008 Envoy with 16500mi) has now been 3 weeks at the dealers with no solution attained for this situation....I'm PO'd on one hand because I want my D$*n SUV but at the same time, I want the "devil" to be GONE!:crazy:
 

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2006 chevy trailblazer_ls
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Mine is in the shop right now for the exact same problem. The brakes have locked up on me in the middle of traffic after a light push on the pedal. I think that it could lead to an accident. The first time it did it the traction control light lit up. I took it in and the dealer replace the traction control module. It did not fix the problem. The dealer has it now. They are going to replace the abs control module now. They are not sure what the problem is. I think the dealer is just throwing parts are it until we go away or the warrenty expires. The problem started around 6500 miles. I have 36K on the truck now.

Thanks
 

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2008 gmc envoy_slt
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96 Posts
2 weeks since last trip to shop...fixed? Hmm I don't know yet!

Just to give you an update on the situation....after spending another 7 days at a different dealer, with a yaw rate sensor, lateral accelerator sensor, EBCM replacement.....not yet corrected.

The last thing to be fixed was wiring issue (under doorjamb?) with a terminal not seated properly. Picked it up about 2 weeks ago and it seems to be fixed....will drop back with further developments if necessary. Take this for what it's worth, however my issue was definitely traction control related.
 

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2003 chevy trailblazer_lt
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Brakes apply themselves

Hello,

Dig828, my 03 Trailblazer does the same thing about 10 min into driving.

Driving along at 100 km/hr and all of a sudden the revs jump up to ~3k to keep moving on a flat road. Let off the gas, and the brakes are on, all four corners. (All hot and smoking)

When this first started happening, I'd pull over, turn off the vehicle and wait 20 min. Start back up, keep going no problem. It happens only once per trip, and after the truck warms up a bit (just got it beginning of Dec.).

Took it to the dealer, no codes, brakes are ok.....cannot replicate problem...basically told me I was full of it.

Did some reading and figured it was the Booster. Asked the dealership's brake guy, and he tells me, yes, it could be the booster or the brake switch not allowing the brake pedal to move fully backward. Next time it happens put you foot UNDER the pedal and pull up.

Sure enough, next time the brakes apply themselves, I pull up on the pedal, brakes let go.

Checked the brake switch, it doesn't seem to have anything to interfere with brake pedal travel.

I figure either the rod from the booster to the pedal needs adjustment (if possible), or a new booster is in order. What seems to be happening it since the pedal does not return fully, the vacuum bleed in the booster does not close, so it has vacuum on only one side (like when you apply the brakes), and they slowly apply themselves.

I need to buy a Helm's manual still, then I can see it the rod to the pedal is adjustable.

So next time it happens, try pulling up the pedal while your moving.

Hope this helps.

Eric
 

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Basic Vendor- Skid Plates
2007 chevy trailblazer_ls
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Discussion Starter #20
Eric,

That was actually the first thing I tried... Mine was a simple, "cycle the ignition" and it went away... Mine was 100% electronic/electrical... Some of these posted might benefit from pulling up the brake pedal (and should try it), but mine didn't...

Thanks for the post, though! It'll help somebody!

Mike
 
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