Brake pedal hard to push

T.O. · September 14, 2021

I also tried pushing the pedal to the floor twice. I pushed it until it stopped and then held it there for about 5 seconds. Let it up on it's own then did it again. The brakes are significantly better. They feel so much better. Thanks for sharing the idea TheElementalCashew!!

Random · September 16, 2021

On 9/10/2021 at 9:16 AM, TheElementalCashew said:

I had this problem on my 2021 AT4. Very soft brakes that would only get firmer if I pumped the pedal, and creeping at stop lights.

This fixed the problem for me: place the truck in park. Depress the brake pedal as far down to the floor as physically possible. Release the brake pedal and let it travel on its own all the way to the top. Repeat the process one more time.

After doing this, my brakes act as I would expect on a truck this size.

As others who have tried, this seems to actually work. I performed these steps a couple of days ago and I've noticed a big difference in the brake feel and performance. Kind of surprised it worked, but I'm not the most knowledgeable about brake systems. Anyone have any ideas why this seems to help?

aliveguy5 · September 16, 2021

39 minutes ago, Random said:

As others who have tried, this seems to actually work. I performed these steps a couple of days ago and I've noticed a big difference in the brake feel and performance. Kind of surprised it worked, but I'm not the most knowledgeable about brake systems. Anyone have any ideas why this seems to help?

This worked well for me as well. I did that and a quick booster test and now my brakes feel the same everytime I drive them with a nice firm pedal.

GMC4Zee · September 24, 2021

I would say that maybe there is air in the lines somewhere. When you push it to the floor a few times you are purging it further down the line. Possible past the ABS system. I have always wanted to replace the rubber front lines with SS ones and bleed the system. I have SS lines from my 2016 2500. If they fit the '21 AT4 3500 I would put them on. I have not looked into that yet. I also have had the creep issue and almost rear ended a car at a stop light.

Edited September 24, 2021 by GMC4Zee

Random · September 24, 2021

10 hours ago, GMC4Zee said:

I would say that maybe there is air in the lines somewhere. When you push it to the floor a few times you are purging it further down the line. Possible past the ABS system. I have always wanted to replace the rubber front lines with SS ones and bleed the system. I have SS lines from my 2016 2500. If they fit the '21 AT4 3500 I would put them on. I have not looked into that yet. I also have had the creep issue and almost rear ended a car at a stop light.

Have you tried the steps yourself to see if it also improved your creeping issues?

So far, my results have been the same since performing the process myself 10 days ago and I haven't had it creep on me at all which is a peace of mind.

GMC4Zee · September 25, 2021

Random, will try this weekend. Been in lockdown due to covid this week. Hope the pedal process works.

[email protected] · October 2, 2021

Thanks for the info. I did the push pedal method today and seems to have firmed up. Hope it stays and not something I have to do daily or weekly.

bird_dog0347 · October 4, 2021

I just picked up a 2020 2500HD used and found this thread, also fixed my problem hopefully for good.

Stuart Brotherwood · May 16, 2022

Yes absolutely I just went from a 2017 F250 to my new Hd2500 AT4 and I feel the brakes are very soft almost to wanting to pump the pedal to get some bite, I scared myself several times from the brakes just not stopping. I jump in and out of our vehicles all the time and these brakes just feel spongy, especially as this is a hauling machine, I haven't pulled my trailer yet and I have a long trip pulling a car trailer and car and I'm very skeptical about how this truck will stop with extra weight pushing it!

bird_dog0347 · May 16, 2022

12 minutes ago, Stuart Brotherwood said:

Yes absolutely I just went from a 2017 F250 to my new Hd2500 AT4 and I feel the brakes are very soft almost to wanting to pump the pedal to get some bite, I scared myself several times from the brakes just not stopping. I jump in and out of our vehicles all the time and these brakes just feel spongy, especially as this is a hauling machine, I haven't pulled my trailer yet and I have a long trip pulling a car trailer and car and I'm very skeptical about how this truck will stop with extra weight pushing it!

Have you tried the suggested "fix" yet? Start the truck and leave it in park, push the pedal as hard as you can to the floor once or twice and should be MUCH better after you do that. I've got almost 10k miles on mine since doing that and the brakes are like a normal car/truck now (aside from squealing).

nards444 · May 23, 2022

I tried the pedal to floor a few times. Its better then it was, but the brakes still suck on this thing. I think the booster more than the brakes themselves. Rumor was at the dealer GM was debating a recall for brake boosters but this was 6 months ago.

spartus · June 6, 2022

I just received my 2022 after a 6 month wait( sat in a farm field for 3 months). The brakes totally suck and have almost rear ended several people. I feel like I’m going to push my foot through the floor trying to get this mule to stop. My 2003 and 2007 2500’s had excellent somewhat sensitive brakes.

I’ll try the pedal to the floor first thing in the AM.

jpamp0817 · June 8, 2022

On 6/5/2022 at 10:13 PM, spartus said:

I just received my 2022 after a 6 month wait( sat in a farm field for 3 months). The brakes totally suck and have almost rear ended several people. I feel like I’m going to push my foot through the floor trying to get this mule to stop. My 2003 and 2007 2500’s had excellent somewhat sensitive brakes.

I’ll try the pedal to the floor first thing in the AM.

This is happening to me. I ordered mine in august 2021 and received it in May 2022. I notice the brake issue where it feels spongy. Have you been under the truck? Mine is FULL of rust. It looks from the salt on the ice in Michigan where it sat. I might be going in for a service and ask for a recall because there are TONS of rust on metal parts and one is FULLY rusted with 500 miles...