i was wondering i changed my clutch in my 97 chevy 1500 and now it seems to be slipping again whenever i first start out all the way to the forth gear it seems like it has no power and whenever i hit a hill it really has no power i didnt bleed the the lines and im wonderin if this is the problem can you please help ? tyvm 
Park the truck. Set the e-brake firmly. With the transmission in high gear, rev the engine and quickly but smoothly release the clutch…The engine should quickly stall as the clutch “bites”. If the engine will not stall, the clutch is slipping badly. To check for proper disengagement, with the engine idling,
can you clutch and slip it into reverse without any grinding?
what exactly did you replace??? disc, p-plate,throw out,flywheel,pilot ??? more info needed
I replaced the entire clutch assembly,included with the hydraulic slave cylinder
While the system definitely needs to be bled, you apparently have another problem. Air in the system would make the clutch hard or impossible to disengage, not make it slip.
what did you do to the flywheel? resurface or replace or nothing.
the flywheel was replaced also i took the truck in for a diagnosis and they said it didnt seem to have any problems with the clutch itself and that everything seems to be in proper working order and the the truck might need a new fuel filter which i changed yesterday and the problem still persists i might add that when i accelerate there seems to be somewhat of a “vacuum cleaner noise” coming from the engine compartment or general area the more i give it throttle the louder it gets its not real loud or obnoxious but its definetly there so i changed the air filter checked for vacuum leaks using cabureatour cleaner my next target of suspicion is the catalyic converter could this have something to do with the loss of power? i might also add that when i let off the throttle and get on it again the problem with the no power becomes immediatly noticeable for about the first 30 secs or so it almost feels like theres a miss in the motor or weak fuel? this has all been addressed the motor itself runs fine i tried higher octane fuel the fuel pump is less than a month old the fuel filter has been changed yesterday maybe i just need to change the whole truck out lol j/k thnk you for your time and patience
I think you may be on the right track about a restricted exhaust. One way to check this is to temporarily disconnect the exhaust pipe at the cat and see if the power is back. The restriction could be a melted honey comb or some other restriction in the exhaust pipe i.e. crimped pipe, loose muffler baffle, etc.
Let us know what you find.