1999 Tahoe Hydroboost Install

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Goldhawg

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I just came across this old thread while searching for a few items...

I went ahead and installed a hydro unit so here are my thoughts:

I purchased a complete (new) ACDelco system that would have fit a '99 3/4t Suburban w/rear drums. Here's a link to all the part #'s http://www.gmc4x4.com/topic/120-hydroboost-conversion-part-s/?hl=hydroboost

For this to work properly and not overheat, you really need to purchase everything in the part list (then there's no need for a "t" connector). Also, you have to remove the variable speed sensor for the system to function properly and install the GM bypass.

Also, the hydro brake pedal were notoriously difficult to find, but LMC now sells them brand new for $35 IIRC.

One important aspect to pay attention to -- different hydro units and PS pumps have different pressure ratings...so try not to mix & match. Find one truck you want to mock your system off of and stick with that setup.

I hope this helps!!

Can you comment on how your steering is w/o the variable speed assist? I read another poster complain that it made his already not tight steering very--forgetting his words--floaty(?). Comments on steering after the bypass? THX!
 

sparg93

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Can you comment on how your steering is w/o the variable speed assist? I read another poster complain that it made his already not tight steering very--forgetting his words--floaty(?). Comments on steering after the bypass? THX!

Yes, it's very soft unfortunately...essentially the PS pump is running full pressure to the gear at all times. At low speed it's like driving it from the factory, but on the highway you notice it the most b/c this is when the variable speed would normally kick in.

It drove me nuts at first, but now I'm used to it and barely notice the steering.

When I can find a few minutes, I'm going to install a steering stabilizer and it might tighten things up a little bit.
 

HOEIN

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Mine drives fine but then again I have 12.5 wide 33s with a negative offset. Not much of a difference on my hoe
 

raptorforme93

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Ok so I've been doing some research on this lately and have a few questions.. I have a 96 Tahoe so I don't have to worry about any steering assist correct? And using the plate from eBay and mods I will be able to use my stock brake pedal right? I am definitely going to put a PS cooler on it also. The parts from here are everything I will need?
http://www.gmc4x4.com/topic/120-hydroboost-conversion-part-s/?hl=hydroboost

I'm upgrading to Hawk pads at the same time and I want to put the 3/4t calipers on it and it's my understanding that you still use the 1/2t brake pads with those? Thank you!
 

sparg93

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Ok so I've been doing some research on this lately and have a few questions.. I have a 96 Tahoe so I don't have to worry about any steering assist correct? And using the plate from eBay and mods I will be able to use my stock brake pedal right? I am definitely going to put a PS cooler on it also. The parts from here are everything I will need?
http://www.gmc4x4.com/topic/120-hydroboost-conversion-part-s/?hl=hydroboost

I'm upgrading to Hawk pads at the same time and I want to put the 3/4t calipers on it and it's my understanding that you still use the 1/2t brake pads with those? Thank you!

An ebay plate?

Personally, I would just swap brake pedals. If you swap with OEM gear in it's OEM position, chance of failure is fairly low. If you modify that area to use a different brake pedal, it's always possible premature failure will set in.

You'll be swapping power steering pumps for this mod so it depends on the one you purchase. With the new one you purchase, just check to see if it comes with the variable component and then purchase the bypass if you need to. Do not use your stock 1/2t pump, it's not the correct unit.

When I did my swap, I also had 3/4t calipers, so I went with 3/4t pads...but I had to do some grinding on the pad to make it fit. I did not test the hydroboost system with 1/2t calipers.

For Hawk pads, I would recommend the Severe Duty over Light Truck. They are whisper quiet and do not produce any noticeable amount of brake dust over the LT's.

Here's some more info for you on our brake setups - http://www.gmc4x4.com/topic/119-spongy-brakes-testing/

Yes, that first link has all the parts you need --- hope it helps!!
 

SunlitComet

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change the pedal, the standard calipers will do great on there own with hawk sd pads and you will not need to worry about the evo system on a 1996 however the the pump to booster hose is not the same as listed either. you will need to pay attention to that for a 1996 vehicle or be stranded until you get the right one.
 

raptorforme93

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Awesome, thank you guys very much! That helps a lot and basically answers all of my questions :)
 

Tbruz

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You are correct regarding the EVO steering, Its not on a 1996.

Two separate issues here plate and pedal

1) Ebay plate is for centering the hydroboost unit in the existing firewall hole.
If you already have the HB unit and its centered in its mounting plate you don't need the Ebay plate. If your HB unit is offset to the top or bottom of its mounting plate you'll need the Ebay plate.

2) The Vacuum pedal and Hydroboost pedal are DIFFERENT
HB pedal has less space between its pivot point and the actuator arm pin.
Use the HB pedal.

Tbruz
 

raptorforme93

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Ok awesome, I'm glad there's an actual reason to use the HB pedal instead so I'll definitely be getting it also

Sent from my SPH-L720 using Tapatalk
 

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