I have a 95 , 1 ton 4wd chevy diesel dually truck that has no brakes? For years there was a slime on top of the brake fluid , but no problems at all so I left it alone. The first time it lost brakes I was mashing on the pedal while the truck wasnt running and the pedal went to the floor and only at th last 1/8"travel did the rears lockup , no fronts whatsoever. I let it sit for a bout a week go back , it has perfect brakes again , how did it do that. I drove it like this for a bout 6 months then the other day it does the same thing again.What is causing this , has anyone else had this problem please help thanks chris:mad:

Your brake fluid like any other fluid needs to be changed once in a while, even brake fluid. Especially if you use your truck on construction or any other dirty invironment it can get contaminated. Could be some fine particals of dirt have worked there way down to the piston on your mc and damaged the rubber seals thus voiding Pascals' Law Of Hydraulics.
As well you might want to check for a blown brake cylinder and make sure the vacuum line to the booster is ok and visually inspect all brake lines. Hope this helps.