RSTahoe99
TYF Newbie
Yes, hydroboost does remove the booster from the braking system. I'm pretty sure you have to have an adapter plate fabricated to mount the hydroboost reservoir to your firewall. Then run high pressure lines from your power steering pump and steering gear box. I'm not sure the exact procedure. There is more about the conversion in this thread from Whippled2dr:
http://www.tahoeyukonforum.com/forum/showthread.php?t=1408&highlight=hydroboost
You are right about the brakes being hard if the booster goes out. All I can say is that your still getting air in the lines from somewhere. Air is what causes the spongey feeling 90% of the time. I too, have the spongey feeling in my brakes a little, but just decided to live with it until I convert to hydroboost.
Hydroboost replaces the vacuum booster with a hydralic booster that runs off of the power steering hydralic circuit.