If your Chevy S10 truck uses manual transmission, it has a clutch system that uses the same fluid and hydraulic method as the braking system. If you had to replace the clutch master cylinder or perform any other task that opened the system to air, you must bleed that air out of the system. Bleeding a clutch system is similar to bleeding the brakes on any vehicle. On most models of the S10, the clutch master cylinder and its release cylinder are located to the left of the clutch housing on the driver's side of the engine compartment.
Fill the clutch master cylinder with fresh DOT 3 brake fluid using a suction tool like a turkey baster (one that has never been used) to deposit the liquid.
Raise the truck's front end and support it on jack stands.
Remove the dust cap covering the release cylinder's bleeder valve. Stick one end of a small plastic hose on the valve and insert the hose's other end into a small clear bottle containing about two inches of brake fluid.
Open the bleeder valve on the cylinder while another person pushes down on the clutch pedal inside the truck. Look for air and fluid to come out the hose and into the bottle.
Close the valve once the second person has pressed the pedal all the way down, then have that person release the pedal.
Repeat each of the previous two steps until fluid cleanly comes out the bleeder valve with no air, then close the valve for good and reconnect the dust cap on it.
Lower the truck off its jack stands.
Keep watch on the amount of fluid in the clutch master cylinder and add more fluid if it gets low.