Ok. I've replaced the brake booster and it seemed to fix my surging problem when I hit the brake instantly. Until I got about 20 miles up the road and now its back, but not nearly as bad.My newest issue is it being really hard to start.Especially once it gets warmed up. Use to fire right up. Ive replaced all the things like plugs,wires,fuel pump and ignition coil.Seems like its not getting gas.I love my truck. Please help.

It definitely sounds like the hydro booster. There are videos on YouTube that shows you how to do either. Depending on your skill level will determine which one you do. The main issue is bleeding the air out of the booster. It can be difficult. You will also need to bleed your brakes completely afterward. GMs are notorious for having the hydro boosters die on them.

Take your tires back off and see if the brake calibers and brake shoes are lined up correctly,maybe the brake calibers are sticking.

check the switch on the brake pedal . do they work until you hit the brakes?

If the brake pedal goes hard right BEFORE the car dies, and not after, then you could have a problem INSIDE the brake power booster. try to verify this next time it dies at a stop, if you can safely pull the dead car off the road into a driveway (or try to make it stall in a bumpy parking lot) - then before you try to restart the car, open the hood, pull off the rubber hose where it's plugged into the brake power booster --> you SHOULD hear a big "Swoosh" of air being sucked into the booster because there's supposed to be a strong vacuum there even after the car stops running. if you get nothing there, your car is dying of an excessive vacuum leak through the brake booster.= bad booster.

generally means a failed vacuum booster, that is the thing which looks like two plates stuck together between the master cylinder and the firewall/ not unknown to have a bad vacuum line or the check valve stuck into it. So make sure that is not an issue before you replace the booster as it is kind of a hassle.

You are going to think I'm nuts but, it's probably the power steering pump or, and most likely the rack & pinion. Your own description of the symptoms are common indicators of a bad rack & pinion. The turning left thing is also a classic sign.

It will only get worse and, could jam on you while driving. You dont want that!!!
Have it checked soon.

I wouldn't install a used brake booster,but you could

You don't need instructions & a list of tools

If you & your friend together need that,you shouldn't
be doing that job

You will find 4 nuts in plain site, on the firewall holding it on.
You know enough to remove the brake tubing on the master
& can unbolt it ,to swap to different booster. Not sure
you can leave the brake lines in place until you try removing
the booster.

Before you do all that ,remove & check out the vacuum
check valve on the booster with the hose going to it

They are a somewhat common replaced item. You may
only get a couple in your life time,but they do fail somewhere
every day.

Sounds like a vacuum leak. Probably in the brake booster. Put it in park and push the brakes while it is running. Raise the hood and rev the motor up. If it is a leak you should be able to hear it. Mine had a hole in the diaphram of the booster. Didn't leak until I hit the brakes.

Bleed right rear,left rear, right front, left front in that order to be sure of good bleed but the brake booster makes it easy to push pedal. Make sure of no leaks from master cylinder. Otherwise brake hoses being soft will also hurt baking quickly.

you could have a brake booster issue. you can do a simple test on another car by leaving the engine off and press the brake repeatedly 3 or four times will use up the vacuum in the brake booster. Once you have done this does it feel like the brake pedal in your van?