My ac doesnt work in my 2001 tahoe

the a/c system needs a minimum pressure before the system will run. the system must have a leak so just buying freon may last a day or a few months depending on the size of the leak. also leaking freon into the air is ozone depleating, it should be recovered properly.

the system needs to be recoved of all freon. vacuum to -30psi held checked for leaks. (uv dye or nitrogen and soapy water). leaks fixed. vacuum to evacuate moisture and air. refilled with proper amount of freon (too much or too little make the air not as cold).