2011 Hydroboost swap

Banshman · Nov 20, 2025

Anyone do this swap on 03-07 2500hd? I've seen allot of people have done this with no issues. I did the swap on my 05 and from the get go had issues with the brake switch. First wouldn't shift out of park. Bought new switch that worked for a while, then cruise control stopped working out of the blue. Buddy scanned truck and tested switch saying switch was bad. Got a replacement from rock auto, cruise worked when I tested it but later that day didn't work. Then got a new one from advance auto parts, cruise still didn't work and then brake lights didn't work. Returned that one and put the second one from RA back in. Now It won't shift out of park unless I shut the truck off, turn key to run and fiddle with brake pedal. Once i can get to neutral I start the trucking and go. I'm at a loss here. The hydroboost looked identical side by side with my original one. And I did use a new gm part. Anyone have any thoughts? Please?? I'm going nuts with this.

stutaeng · Nov 20, 2025

I ordered a 2011 Duramax HB from a RA for my 06 Suburban 2500, but dumb UPS lost package...I put in a claim last Friday and I have yet to hear from them. But on TYF, one guy recently posted that he'd done it on his 01: https://www.tahoeyukonforum.com/threads/can-i-use-the-“better-2011”-hydroboost.145191/#post-2011692 Post #8...

Why would the brake switch make a difference?

I don't think the brake switch would know or care what HB is installed, assuming it snaps back into place and the pedal position is not changed?

Can you find a bi-directional scanner and confirm the brake pedal is pressed whenever you physically press it? I believe there's a PID where you can monitor that IIRC. If the brake switch is reporting something else, for sure the cruise won't work and you won't be able to shift out of park. "New" parts lately seem to be pretty bad as far as them working straight out out of the box, sadly...:-(

Use the brake relay switch "clicking" to your advantage as well as a diagnostic aid.

Banshman · Nov 20, 2025

The scaner doesn't show pedal pressed when pressing. I was wondering if the rod from the hydroboost is off by a tiny amount that contacts switch. That's why i was curious if anyone has had the issue. I'm on my way to get a gm one at the junk yard since the part is discontinued. Update incoming

Banshman · Nov 20, 2025

Installed the junkyard gm switch and everything works like it should. What a pain in the ass

AuroraGirl · Nov 21, 2025

Banshman said:
The scaner doesn't show pedal pressed when pressing. I was wondering if the rod from the hydroboost is off by a tiny amount that contacts switch. That's why i was curious if anyone has had the issue. I'm on my way to get a gm one at the junk yard since the part is discontinued. Update incoming

That would be a C for Chassis kinda live data if you want the more accurate/specific live data inputs , for the EBTCM (ABS) system