"How To": 2002 - 2006 Chevy Avalanche/ 1999-2006 GMT800 Hydroboost Replacement

*At the 18:40 mark, I put the bracket on first, then the master cylinder. This is incorrect. Put the master cylinder on, THEN the bracket. I realized I did it backwards and then forgot to change the video clip in editing.*
Not all GMT800's came with a hydrobooster, but for those that did, the hydroboost system in GM trucks is a critical component to both the brakes and power steering. The main reason they need replacing is due to leaks. Considering how easy it is to replace the unit as a whole rather than rebuilding it, and how long they typically last, you're usually better off just putting in a new unit.
Be sure to bleed your power steering system after replacing the unit, and if you removed the brake lines from the maser cylinder, be sure to bleed your brakes as well. Bleeding your system must be done before driving the vehicle .
Torque specs for the various nuts and power steering lines are:
Master Cylinder retaining nuts: 27 lb-ft
Hydroboost firewall stud nuts: 24 lb-ft
Power steering lines: 20 lb-ft
Where to buy:
www.rockauto.c...

[@jd4519]

Hoping to see the bleed sequence to the hydro boost

[@waw225]

The studs on the HYDROBOOST unit that the brake master cylinder is attached are attached with left-handed threads. Removal of these studs with a 13mm wrench makes removal and installation of the HYDROBOOST easier.

[@takeroadslesstraveled6505]

Appreciate the advice

[@candyrae8059]

My husband is having major issues with his truck. He replaced his rotors, brakes, calipers and now his brakes lock up and smoke when trying to accelerate on freeway. He than put new hydro booster and master cylinder, and still doing the same thing. We have spent $1,300 and don’t know what to do now to fix it or what is the areal problem.

[@thomasbedford1692]

Sounds like an abs problem

[@MrsBuddevil]

Did you guys get your problem figured out? My bf has been struggling with exact problems

[@mahadeogokhul8013]

Bro, you put the bracket in before the breaks fluid reservoir. Please look at your video from the start, the bracket goes on last before the two nuts.

[@takeroadslesstraveled6505]

Yeah, I know. I realized it after and never reshot the install. I need to just re-edit the video. Appreciate the heads up though!

[@dieselprime504]

I was just saying the same thing. This will definitely lead to premature failure smh. Easy easy mistake.

[@mred305]

Great video

[@joseguillermomagana4340]

Se le puede poner una palanca de cambios al piso a una avalanche 2003 ?

[@takeroadslesstraveled6505]

Anything is possible with ingenuity and enough money.

[@MegaHowtoMan]

How do you know if you have a hydroboost? I have 03 Tahoe 4x2 LS. 5.3L.

[@takeroadslesstraveled6505]

Look under the hood, right next to your fuse box. If the setup looks like the one in the video, you have a hydro boost. If you have what looks like the body of a 2-quart pot sitting there, then you have a vacuum boost.

[@miguell6788]

You installed the master cylinder bracket wrong. It does not go between the hydro booster and master cylinder that will leave you with a gap. It goes after the master cylinder then the nuts hold it in place

[@takeroadslesstraveled6505]

You’re right, I did, and somehow I ended up putting in the wrong video clip cuz I realized it and had to go back and fix it. But, thank you for pointing that out!

[@trreno1980able]

​@takeroadslesstraveled6505 what does the hose go to on the front of the master cylinder mine does not have that or an electrical plug?

[@sirfloyd6495]

Hey the bracket supposed to go behind the power booster master cylinder you did it wrong

[@takeroadslesstraveled6505]

Yeah, I know. I have a note in the description on it as I realized it and messed up the video edit and put the wrong clip in the video.

[@miguell6788]

Otherwise great video!

[@wolfsmane]

Is that clip holding the plunger rod to the pedal, on the passenger side or driver side of the pedal? BTW - a 6'3" 290# guy trying to get under there to remove the clip....whew, LOL!