Bad Brakes

I have a 1988 1/2 ton 4x4 and the brakes suck! They never were too good and now the truck has sat awhile and they are worse. You can stand on them and not get them to lock up. It takes a heavy foot to stop. I was used to it but am handing the truck down to my son and it has me worried. I put new rear cylinders on awhile ago. Just put a new master on. I did a test to see if booster is working. The only other thing I can think it would be is the front calipers? But then a guy told me all