1994 Ford Ranger Clutch slipping when hot- clutch has 1000 miles on it.

Clutch rebuild kit and slave cylinder installed by Pep Boys- has 1000 miles
on it and seem too tight. Slips when hot, disenguages fine. Can I fix it
myself. What is problem? Air in hydraulics?
Just bought truck last week. Only true 57,000 miles!

Also fuel gauge not working-no movement. Stays on E. I think they did
something when replacing Clutch.

Thanks

could have oil on on clutch plate andclutch plate could not be seated and
also sometimes it can take about 30 or 40 normal starts to seat a new one
and if pep boys install it there might be a warranty