As many people know GMT800 SUVs often come from the factory with hydro boost, as do the diesel trucks. Hydroboost is a common and very worthwhile swap into any truck that originally came with a vacuum booster even if your not running a big cam, the pedal feel is immensely better IMO.

I recently stumbled across there being possibly four different hydroboost units that fit GMT800 trucks all with minor spec differences.

The first is the the u it’s that came in GMT800 1/2ton SUVs like my 2004 Tahoe. According the RockAuto parts description they are for trucks with 7,200# brakes. Not really sure what that means TBH.

The second is the obvious diesel unit that is common in all duramax trucks from 01-10 and according to RA is for trucks with 12k# brakes.

The third is the Hummer H2 units which is for trucks with 9,900# brakes.

The more interesting one is the 2011 LML duramax unit, which according to all the diesel bros is a considerably good upgrade to the 01-10 diesel units. Unfortunately I cannot seem to find a # number for this to see how much more it’s rated for or whatever that number really represents.

I recently swapped out my original 7,200# unit and swapped in a 12k# unit and notice a massive upgrade in pedal feel. I’m not saying the truck is gonna stop harder because with the brake upgrades my Tahoe has it already struggled to find traction to brake, and made the ABS work hard. However from the driver perspective it feels significantly more sensitive and better.

 

Cool. Do you happen to know the RPO codes for each of these brake setups? 🤔

 

I'll find it on my '07 H2 tonight

 

I’ll check my tahoe in the morning.

Heres some RPO codes related to it in the master list. The only one I see as matching anything is the JK4 is related to the 12,300# unit.





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Dan needs better google skills

 

So the 12k and 14k hydroboost units will swap into the 9k and below?

My suburbans with the LQ4 both have JH6 rpo code. I haven't replaced the hydroboost on them yet, but I know they eventually leak. I wouldn't replace them if they ain't leaking, but if they were, might as well upgrade them. 🤷

I did replace the hydroboost on my old K3500 CCLB SRW when I'd just bought it. It's not too bad. Removing the pedal clip under there is the hardest part of the job that I recall.

 

I know the brakes in my boss' 2013 2500HD Duramax are really sensitive and have super stopping power.

After I did the full brake fluid flush on my 01 they got a bit better, actually chirped the tires while doing a test panic brake which it never did before. They don't have that crazy sensitivity as his truck but will stop well if you push hard.

 

Ok smarty pants now find me something that says for sure the 2011unit everyone wants is directly related to JH9.

 

didn't realize it was my job to prove your theory 🤣

 

You clearly proved my Google skills are lacking, therefore you are the most qualified person between the two of us.