Truck Repair: 1998 Z71 crappy brakes, rear wheels, z 71

Question
I bought this 1998 Z-71 truck w/40,000 in 99 and now have 142,500.  I love this truck, but the brakes are pathetic.  They appear to share parts with my Astro van.  Calipers look identical.  Several shops, including the dealer say that there is nothing wrong with the brakes.  That that is why they went to 4 wheel disk.  I don't know what to do as there is no better than 50% of the braking than is on the '03 that i rented or on my brothers 94 (with 275,000 miles).
Please help me stop before i crash again...
Michael

Answer
Hi Michael,
I don't know why they would say that, but I have had trucks in that age range, and the brakes were not pathetic on them, unless there was a problem, like the booster not working, or a valve in the antilock leaking, or the front brake hoses restricted, or the master cylinder only working on the rear wheels.
The antilock system is on there to keep the wheels from locking, and the system should work real well, not pathetic.
Midas, maybe?
Van