H2 Brakes locking while backing up. Intermittent
 

Intermittent problem with the brakes locking, applying by themselves, or sticking when backing up. 2004 H2 w/ 168,000 miles on the ORIGINAL bakes pads. There is an intermittent problem that as I back up, not applying the brakes, the rear brakes engage after about 5-15 feet. it can be as little as feeling them drag, or as hard as...wtf...just happened. I know some will say change the pads but every year when I have the vehicle inspected my buddy who does the inspection says they are barely worn...Hummer must have made them good! And, the local shop owner in my town who was the service manager at Hummer said the same....don't ever change them if there is no problem. H2 did sit for a few months over the fall and into winter and that is when it developed, but I tried to drive it weekly or bi-weekly to get his juices flowing. My questions are:

1. Is the anti-lock being applied?
2. Traction control not working right?
3. Emergency brake system not working right?
4. Rear diff not free spinning?
5. Trans or transfer case problems?

Has anybody else had this problem?

I had rear seal on right replaced at about 40k because they said it was leaking...Only issue I have had from back there.

It's a shame that I posted this question over a week ago and there hase not been any feedback at all. Surely there has got to be a person with some prior knowledge to this issue.... Please help!

No responses because you posted it in the wrong section.

First off, you are the only guy in N. America with original rear brake pad at 168K miles on anything. You have more than one problem going on.

If your rear pads are still in tact with that mileage, you may have a braking imbalance not being properly controlled by ABS. When you start the truck does the ABS light come on when you start the truck for a second or two? That tells you the system is checking itself (no light at start, no initial check).

Does the condition you describe only happen right after you start the truck and move it in reverse, or can it do it after the truck has been driven for a while? If it happens only right after you start it and first move a few feet in reverse, that is the secondary ABS check that you feel.

You may have a caliper piston that is corroded and/or hung up, and if you would have changed the pads, you would have cycled the pistons and either found that problem, or possibly freed up the seized piston.

I would take it to a reputable brake shop to have it checked out, not your inspector buddy.

Kata a body of mine had the same problem with his 06 back at 146k with original brakes and all it took to fix was new brakes all around . But like Doc says take it to a good brake shop and let them look at it ...

OK. With no disrespect..... My buddy who does the inspections is a prior mechanic for the Hummer dealer that was in south central PA. My service consultant at the local shop was the most knowledgeable service manager I have ever seen...and he was "the" service manager at the Hummer dealer. Both told me the H2's had outstanding breaks. ALL of my break pads are not worn, including the fronts at the mileage i have in the H2, 168k. I thought that I was able to trust these factory trained individuals....and I do. Yes, the ABS light does come on at startup and then cycles off. The ABS light has never come on for any other reason. The problem has happen before after driving the vehicle for several miles and then backing up. Thank you for your input and continued help would be appreciated. And once again....my Hummer certified mechanics told me never to change all those pads unless they are worn or I would be sorry for the inferior crap that is manufactured today, being the pads and rotors. Thank you for your help. Ken.

I can see your point about not touching the pads if they are not worn. I don't even have 60k on mine and my pads look like they're brand new. Even that mileage I'm tempted to change my pads because I need to change the brake fluid anyway as its completely black.


Doc brings up excellent points though. You're pads probably should have minimally be changed at 100k just as overall maintenance. As far as inferior junk on the market. There are many brands out there which will easily out perform the stock pads. IMO the H2 brakes work so well because the calipers are huge, reason why the pads last so long-not so much the pads but the size and clamping force of the calipers.


Good luck and let us know what happens.

you said that it was parked for a little while. Do you use the parking brake? or if you don't use it did you put it on by accident and now it is stuck engaged and now won't release?


Do you smell burning brake pads after driving sometimes?
this could be a seized caliper. I had this on my mine as it sits and doesn't get driven much.


If you do smell burning pads, determine which wheel it is coming from and pull the caliper off. Get a big c-clamp and a piece of flat bar that is big enough to span the two pistons of the caliper. place the c-clamp in the centre of the flat bar and two pistons and start turning the pistons in. if both pistons retract evenly then your caliper is not seized. However if one stops moving then it's seized. crank the c-clamp up as tight as you can and give the caliper a smack with a BFH. this will sometimes shock the piston and unseize it. Clean up your sliders and re-assemble.

At one time I had money falling out of my pockets and easily afforded my H2 and CTS with cash back in 2004. Now that I am on a VA pension I am strapped for cash and can't afford the required parts as routine maintenance. I do not smell any brake pads burning. I rarely use the e-brake and I do cycle it to make sure it doesn't seize up. When it was parked for a few months I did drive it for 10 minutes at least every other week or sometimes weekly. It's just weird like the ABS was malfunctioning and all of a sudden slamming them on in the rear or applying the gently at times. Like I said....no heat, smell, pulling or wear. They do their job when needed. No ABS lights come on and no other troubles.

My parents just ran into a similar issue with their ford explorer. It turned out to be a worn hub. It got the tolerance out enough to make the abs activate. Dad said he could floor the truck and it wouldn't move.