Ok, so here's the data!!
Due to me being solo for this and a lack of any scientific equipment other then a wheel with a built in counter (no idea what it's called), these numbers have a high chance of error...so please don't take these stopping distances (60mph - 0) as gold. What I think is important is the changes between and overall average of each setup.
Vacuum, 1/2t calipers, 1/2t pads, 265 tires, stock height (OEM setup)
1st pass - 138ft
2nd pass - 136ft
3rd pass - 135ft
Vacuum, 3/4t calipers, 3/4t Hawk LTS pads, Slotted rotors, 265 tires, stock height
1st pass - 146ft
2nd pass - 148ft
3rd pass - 142ft
HYDROBOOST, 3/4t Master, 3/4t PS pump, 3/4t calipers, 3/4t Hawk LTS pads, 285/70R17, 4.5" lift
1st pass - 134ft
2nd pass - 130ft
3rd pass - 129ft
EDIT: On 5/21/13, I did testing on new Hawk SD pads I installed, results below. In this test, there was additional weight in the truck from x2 steel bumpers, one winch, x1 33" spare tire on rim and a steel roof rack. Temp was 90 deg, quite a bit warmer then previous tests and my rear drums had new shoes in the rear (~2k highway miles). Also, I swapped in Bilstein 5100's which provided noticeably better dampening then previous 5150's.
HYDROBOOST, 3/4t Master, 3/4t PS pump, 3/4t calipers, 1/2t Hawk SD (Super Duty) pads, 285/70R17, 5.0" lift
1st pass - 127 feet
2nd pass - 117 feet
3rd pass - 107 feet
4th pass - 112 feet
5th pass - 108 feet
Surprisingly, each day I did the testing, it was about 50deg.
- My shocks were not setup correctly when I did the hydroboost passes, so with firmer valving, I have a feeling a few feet will be knocked off
- During the hydroboost test, my truck was a few hundred pounds heavier with the lift kit, bigger tires and tools in the back then when I completed testing with the vacuum setup
- DO NOT BUY 3/4T CALIPERS UNLESS YOU HYDROBOOST - you're stopping distances will INCREASE. Also, the 3/4t master will not bolt up to you vacuum system
- Hydroboost was able to finally lock the tires and create a small patch of rubber...my vacuum was not able to do that
Using all new AC Delco parts (do not buy cardone, they tend to leak), expect to spend $750+ and three days doing this for first timers. You're upgrading the master cyclinder, PS pump, hydroboost unit, GM variable assist bypass, three lines and you should add a Power steering cooler...this stuff adds up really fast. You can always go used and ppl have had a lot of success, but for brakes, I personally always buy new.
Hydro units have a propensity to leak and are expensive to have rebuilt. If you buy used, definitely get some kind of guarantee that if it leaks, you can return. My first (new AC Delco) unit leaked and it took a week to get another one...
Also, you may need to cut and re-flare brake lines where it connects to the Master Cylinder...so definitely know what you're doing before you rip into your truck's braking system. This is a job that is straightforward, but definitely requires someone who is comfortable working on multiple components and understanding when something is installed correctly (i.e. always replace orings, use line wrenches and torque to the correct settings!)
Everyone has a different preference, but I really hate that i lost variable steering. My rig rode like a boat prior, once I bypassed my variable assist, steering got even softer. With the months of research I did, I could not find a hydroboosted truck that had variable assist....so plan on bypassing it b/c otherwise you will restrict the amount of fluid your hydro unit receives.
I hope this helps everyone in the endless quest to stop these rigs! Please feel free to ask any question you may have!!
Power Steering Return Hose - AC Delco 36-368640
Power Steering Pressure Hose - AC Delco 36-365460
Power Steering Pressure Hose - AC Delco 36-365490
Power Steering Pump - AC Delco 36-517137
Master Cylinder - AC Delco 174-722
Hydroboost Unit - AC Delco 178-578
Variable Bypass - GM #19168825
OEM PS Cooler (from gmpartsgiant) - 26041420 & 15655032 (bracket)
Hydro Brake Pedal - LMC currently sells it
A good writeup for the install - http://www.gmfullsize.com/forum/showthread.php?t=156800
Edited by Hedge, 21 May 2013 - 03:11 PM.