I have a 1996 c1500 4.3L & 5spd. I started having problems shifting from 1st to 2nd and would have to turn off the truck just to put it in reverse. I started looking at the fluid level in the clutch master slave cylinder. It was a little low but I also found the fluid was black and little thicker than normal. Black to me shows the fluid got very hot at some point. I first had a friend pump and hold the pedal then I opened the bleeder on the clutch slave cylinder and some fluid cam out and it was black but there wasn’t a great amount. So I topped of the master slave cylinder and the pedal stays the floor with no pressure. So I removed clutch fluid line from the master slave and blew air through the line and a little more black fluid came out. I reconnected the line to the master slave and with the bowl filled and the clutch line open no fluid came out. So does anybody have any suggestions???

 

Welcome from Florida. The hose connecting the master to the slave may be bad.