Starkweather,
First things first, a Hydro-Vac "sucks". A Hydrobooster uses pressure from a PS pump to help stop.
So, your suburban has a Hydrobooster right?
There is nothing different to do with the brake system when bleeding brakes with a hydrobooster.
When first starting after changing a PS pump, box, line, or hydrobooster you will need to follow some simple steps to work the air out of the pump, so as to not kill it when you start the engine. in short you jack up the front of the vehicle and turn the wheels full left to full right about two dozen times, engine not running. Then you start the engine for about 5 seconds and cut it off. Check and refill the fluid very frequently the entire time. Then with engine running turn left to right a bunch of times again, checking fluid often.
Nowadays Hydroboosters are not recommended for drum drum brakes, as they can be a little funny feeling.
Both of my trucks have disc disc brakes.
One has a 2004 booster and it works very nicely, smooth, consistent, and strong.
The other has a booster from the 80's. It feels about as you describe, I have no problem with it, but it is different.
Hydroboosters are essentially the same from the first ones to the ones used today. However there are many internal changes over the years that give the newer ones a more civilized feel.
Both ford and GM use almost the same boosters, the only difference is the MC bolt spacing and pilot bore.
So, sounds like your booster is normal, you could upgrade to a late model one if you wanted, but I would leave the Burb alone and put the late model one on your 4400.
For someone who really knows Hydroboosters talk to Paul at
http://www.hydratechbraking.com/ He has helped me a bunch with my projects. I don't think there is a question about a hydrobooster he does not know the answer to.
Grigg
