RossEGCA

I have a 2020 AT4HD and have been dealing with this brake issue since I first bought it. I had it to the dealer 10 times, had the pads and rotors replaced several times and the problem never went away. I kept telling them it was an incompatibility issue between the pads and rotors and they could replace them 100 times and it won't fix it. GM Corporate got involved and eventually they told me they were not going to do anything else about it. I could not find aftermarket pads at the time, but found rotors. I bout cross drilled slotted rotors and that helped alot, I was redently at the dealership for a part and the service guy told me there was a new service bulletin and they have changed the pad compound and will replace them again. I have an appointment on Tuesday of next week so we will see what happens.

I've been dealing with this issue for the last 12 months. I bought my 2020 AT4 HD in February 2020 and brakes started to squeal in the first few months. Got the run around from dealer for a while and found the TSB so they put new pads on. I had over 7,500 miles at that time. Started to squeal again and they said can't do anything more. Called GM Corp and after a long time of being ignored they finally kept my truck for 10 days and put new pads and rotors on. Now its squealing again and I'm back dealing with corporate again. It's been in the shop 10 times, mostly for brake related squealing. I'm not sure what more they will do, but I'll see. I'm temped to just buy after market pads and do it my self since the GM components don't seem to be working.

I've been dealing with this issue for the last 12 months. I bought my 2020 AT4 HD in February 2020 and brakes started to squeal in the first few months. Got the run around from dealer for a while and found the TSB so they put new pads on. Started to squeal again and they said can't do anything more. Called GM Corp and after a long time of being ignored they finally kept my truck for 10 days and put new pads and rotors on. Now its squealing again and I'm back dealing with corporate again. It's been in the shop 10 times, mostly for brake related squealing. I'm not sure what more they will do, but I'll see. I'm temped to just buy after market pads and do it my self since the GM components don't seem to be working.

MTI Acoustics in Texas makes amazing speaker boxes with a lot of options. I bought one for my 2020 Sierra AT4 which fits under the rear seat. Carpeted to match the factory carpet and they tune the box to the speakers you choose. Mine was $500 shipped to California.

I have a 2020 AT4HD and its now in the shop for the 7th time since March. This the 4th time the battery has died. Actually already had an appointment for squealing brakes for the 3rd time (separate post). I just called them about tightening the fuse box bolts and gave them the service bulletin number. I had to give them the service bulletin number about the brakes too. Why are we having to tell GMC mechanics how to do their job. This is ridiculous. I expect they will tell me...again....that the battery is fine and there is nothing they found to cause it. I hope its the bolts....still hoping to get rid of the brake squeal too. UPDATE: I picked up my truck yesterday and as I suspected the mechanic said he could not reproduce the squeal on the brakes. I had showed a video of it to the service tech. They also said battery tested fine and they could not find the problem. I showed them the service bulletin reference posted above, but they couldn't find it in their system. I got home and checked the bolts on the fuse box and mine were one full turn lose as well. I hope that resolves the issue with the battery.

https://www.repairprocedures.com/bulletins/document/20na020/5500315.html When I look it up it deals with the squealing brakes. Here is the link.

I had two Tundras before this GMC with no problems, but since Toyota doesn't make anything as powerful I had to switch. After trying to fix the brakes 3 times myself I found a service bulletin on one of the threads. I think it was 20NA020. Local GMC dealer replaced the pads with ones with a different compound. Had mine done last week at no charge and so far they don't squeal. The other GMC dealer I bought it from said normal noise and wasn't aware of the bulletin. It came out in February 2020 and has been updated several times. Print it and bring it with you. The pads were actually back ordered due to demand so I had to wait a couple of weeks.

What did the dealer say about the knocking. My 2020 Sierra AT4 HD Diesel has started making the noise at 7,500 miles. I have to go back to the dealer for the 5th time soon to get the brake pads replaced since they squeal really bad. So many problems with this new truck.

I have a 2020 Sierra AT4 HD Diesel and it has 7,500 miles on it. I just noticed the clunk today. Has anyone had any luck getting the dealer to fix it?

I had the same issue with my 2020 Sierra AT4 HD. I jumped it the first time and it was fine. Second time I charged overnight and it was fine. I took it to the dealer as it threw some check engine codes due to low voltage. they cleared the codes and tested the battery and said it was fine. I said then why does it keep dying? They don't know. So far its been 4 weeks and no other problems. Strange thing is with two batteries there were no warning signs like slow start, etc. Just went from fine to dead overnight.

Glad to hear it. Hopefully they don't start up again down the road. If mine start squealing again I'll have to replace them. I looked for aftermarket pads, but they don't make any yet that I could find. UPDATE: My brakes started to squeal again so I took it back to the dealer with the service bulletin and they replaced the pads. It was quiet for 4 weeks and started to squeal again. I took it back yesterday (dead battery again too) and they said they could not reproduce the squeal. (it literally does it every time I drive it.) I showed the service guy a video I took the day before and he said even if they did hear it they couldn't do anything about it because they already replaced the pads. I asked about replacing the rotors and he said GM would not pay them to do that so they won't do it. Seems like they aren't allowed to think outside the box to fix the problem. I'd be happy if they just turned the rotors to see if that works. I guess I have to pay for it myself. UPDATE: I contacted GM Corporate at 800-462-8782 and told them about the brake squealing issue. The assigned my case to Courtney who never called me even after I left her two messages. Due to lack of communication GM escalated my "ticket" to a different office and they have now assigned a "TAC team" to work with the local GMC dealer to fix the brakes and a dead battery problem. They're giving me a loaner car which makes me think they are going to have it for a while. Hopefully this fixes it. They are now squealing not only at low speeds, but when I apply them at 20-30 mph. So frustrating!

I have a 2020 Sierra AT4 HD. Brakes started to squeal at about 2500 miles. All 4 wheels did it at different times and sometimes all at the same time. Dealership said its normal brake noise. I laughed....it sounds like a garbage truck on Sunday morning. Really loud and embarrassing after spending $80K on the truck. They refused to do anything about it. I've always done my own brakes so I just took them off, cleaned them and put anti-squeal compound on the back. Still squealed. Tried again with a different compound....still squealed. Finally I took them off and since they are squared off at each end unlike most pads I've seen which have a 45 degree chamfer on them I took an angle grinder on the ends of each pad and created that 45 degree chamfer and problem solved. I also used an anti-squeal on the back of the pad for extra dampening. I think the squared off pad edges just vibrate at low speeds. Don't expect your dealership to do anything. Hope this helps.