I recently purchased an '08 Hummer H3 this past summer. I have started to notice that there seems to be a delay in the braking system. For instance, when I start the vehicle and push on the brakes sometimes the pedal will travel about half way to the floor and then it will push back up to normal. It almost feels like there is nothing there. There is no sign of ABS kicking in because there is no noise or vibration in the pedal. I have also tried waiting a min or so after starting to apply the brakes. I have been noticing that it does this when driving too. Sometimes I will push on the brakes to stop and there seems to be more travel in the brake pedal and then it will engage the brakes abruptly causing a sudden hard brake. I am careful to push on the brakes slow and steady, but it still seems to act up at least once everytime I drive it. It is very annoying!! Sometimes I pump the brakes to make sure that I will have brakes because I am not sure when it will do it.

I took it into the dealership for a traction control/Stabilitrac issue and had mentioned the braking issue. They looked over the vehicle and told me that they found that the battery positive cable had corosion and they replaced the battery and connection wires both covered under GM warranty. That's all they fixed and said that they could not find any other issues with it. After getting the vehicle back it seemed to be working fine, but I have noticed the brake issue again since the new battery. Also, the headlights will dim sometimes when pushing on the brakes. I was following my wife home this evening and she got all pissed because she thought I was flashing my lights at her.

Does anyone else have this issue? I have taken it into the dealership twice now and they tell me that they don't notice anything and that the brakes appear to be working properly. This doesn't seem normal at all. I have never had a vehicle that this has happened before. I worry that the brakes will not respond when I need them.

 

How many miles on it, Alpha or I5?



I doubt your battery issue is related, but you may want to review the plethora of threads on the OEM battery terminals are complete crap. Tiny changes in voltage can effect your PCM and BCM, possibly causing a computer related fart, or no starting in cold weather.

The fix is easy, get good quality terminals to replace the loose fitting unreliable OEMs.

 

I see you took it to the dealership. Was it Bergstroms? If not I would go to one of them in WI. I have always had nothing short of great luck with them.

 

Hey Doc Olds, how much does those battery terminals on your pic run you and was it easy to install?

Sorry for thread jacking but I hope you resolve your problem, curious to see what's causing it.

 

It is I5 with about 35,000 miles on it. I did take it to Bergstrom and have been working with the service department.

It did it again over Christmas. I was coming off the highway after driving for a while and there was a delay in the brake system. I did hit them a little hard, and noticed it more - the brakes went down about a quarter to half way and then suddenly engaged causing everything to fly forward.

Does anyone else notice a delay in the braking system or headlights dimming when pushing on the brakes?

 

Have you looked at your rotors and pads to ensure everything is making solid, even contact? Maybe the wear will give you some kind of clue. You can see the some of the inside of the rotor with out removing anything. It almost sounds like you may have some air in the line(s), but that is purely speculative and doesn't explain your lights.

Good luck.

 

lights; last year a lot of guys said their lights dimmed when braking. i have not noticed it on the 2 h3 i have owned. even when trying to make it happen,i monitored the volts with a digital meter,no dip.
also never had ANY abnormal feel on the pedal. i have driven veh that have more "grab" but i consider both h3 normal. yours isnt and i wouldnt drive to the mailbox if mine acted like you describe.

if the dealer cant find a problem that severe, i would report to the police and tell the dealer you did it and that possibly WHEN you have a smashup,at least the cops might come after them,assuming you keep driving it, which i wouldnt, not even to my mailbox

 

There is something like a recall for the brakes also for H3's in the snow belt region too.

 

That has to be the most ignorant response I have heard from you yet. Unless your hiring a cop to fix your brakes they are not going to be able to do anything for you except laugh and kick you out of their building for being an idiot.

O/P, Have the dealer/tech power bleed the system with new fluid, the old may be contaminated or of the wrong type which will cause those symptoms. Spec the rotors for proper thickness and see what kind of pads are installed. Some aftermarket pads are extremely grabby, with 35k they may or may not have been replaced by the P/O. Your brakes and lights are unrelated problems.

 

only helpful and accurate, never using vicious and or vulgar language, i got thrown off the forum. i guess the standards are upside down like everything else in liberal society today.

and yes even if they laughed and thru me out and i ended up smashing into a school bus, the cops would remember,over my dead body!! i think the idiots are at the dealers if they cant find a blatent problem,as he describes. and you are just throwing out wild,obvious guesses. say as u wish,i wont be back on this one till he posts the actual cause!!