07 Hummer, 260k miles. First symptom was "Brakes" warning light and "Low Brake Fluid" message started coming on and off randomly, level was OK, no leaks.
Then "Traction Failed, Service Stab Sys" and the "Traction control" warning light came on, but everything was working fine apparently. After that I started loosing power brakes every now and then and the ABS warning light came on as well, which scared me because the pedal sinked all the way down and I had to pump it real hard 2-3 times to make it stop. I temporarily fixed that by tapping with the handle of a screwdriver on the accumulator/tank(motor isn't accessible) of the H3's Hydroboost assembly everytime I ran out of brakes, until it gave out completely. Brand new assembly is $1,200 more or less(which I wasn't willing to pay) so I thought that a Colorado/Canyon brake system could fit since they share the same engine dashboard, started Googlin' the Colorado brake pedal and comparing it to the Hummer's and they were the exact same, also compared the brake booster, pedal shaft, and bolts and were pretty similar to the H3's, as well as the firewall and mounting hole. Bought the master cylinder and brake booster from a 2005 Colorado 5cyl. at O'Reilly's, two 3/16 x 8" M10x1.0 brake lines(which is the Colorados M.C ports thread) but couldn't find a "Tee" fitting with that thread at any autoparts store nor industrial supplier, but got them on Amazon, I also needed the plastic adapter plate/spacer that goes on the back of the booster, found one at a junkyard for $40, took it off the booster and then returned it as a core so it paid for itself.
Ended up spending roughly $300(260 for parts and 40 for labor) I installed everything at the mechanic shop and just paid them to bleed the system. I live in South Texas so everything is cheaper here And don't forget a foot of 1/2" heater hose to connect the vacuum to the booster(H3's already come with a connector at the intake manifold but it's capped, you'll see it right away.

 

Thanks, having modified our H3T (SAS/SOA) and soon to be changing out the rear differential removing the entire ABS/Hydroboost may be in my future.
Any lights on the dash? How do the brakes feel minus the hydroboost?

 

Pedal feels softer but in a good way, it's easier to control the amount of power you put on the brakes now, but it'll make the tires squeal if you jam on them.
The only problem is the dashboard, looks like a christmas tree now hahahaha!

 

Thanks for the most excellent (picture bill & ted) update/write up dude! Lol. This is really using your thinker. More and more we are having to come up with work arounds. This is a decent way to extend that knowledge and the life of the H3.
It sucks that Jeeps that are from the 70's can get damn near every part but are vehicles which are from this century cant get squat. Of course if its chrome bling, bling the vendors have got it.
I agree that price is stupid crazy $1200. It just goes to show the Hummer tax is still alive and well hahaha.

 

You're welcome sir, I tried my best! Spent a lot of days looking for parts online, comparing them and watching videos on YouTube until I decided to run the risk of buying all the parts, it's my daily driver so I couldn't test fit anything without needing to bleed the whole the brake system.... alone! But I'm glad it worked and didn't have to spend $1,200, I also think it's crazy that there's no aftermarket support for H3's, considering they share a lot with Colorados/Canyons, we'll see how hard it'll be to get parts on the future.

 

I would have just bought a used one from a local pick n pull, your time saved in masterminding it would have made it a wash.

However, Kudos on the work around.

 

only thing missing is a clear and complete parts list for the next guy to follow

 

I went to 3 junkyards and they wanted $500-600 and my core, they all googled it to check the price.
It's been a long time since I washed it hahaha my work schedule is killing me.

 

Good idea!

PARTS LIST:
(1) 2005 Colorado 5cyl. master cylinder w/reservoir
(1) 2005 Colorado 5cyl. power brake booster
(1) 2005 Colorado 5cyl. brake booster with the plastic spacer/adapter from a junkyard (couldn't find it anywhere else, they won't sell you the spacer alone) and don't forget to get the nuts that hold the M.C to the booster.
(2) 3/16" x 8" steel brake line, metric thread-standard flare. (PAJ-308) from an Autoparts store.
(2) "Square metric tee" M10x1.0 female inverted fitting from Amazon.
(1) foot of 1/2" heater hose.

 

Hi, thanx for this, 4x4 is still working after hidroboost removal ?
Thank you so much!!!