I am living in a rental property where the landlord will not pay to have the a/c fixed. I seem to have a leak in the system b/c I have had to have the unit charged twice in two months. Bith times I have had 2-3 pounds put in. I do not want to keep paying for this myself. Is there any way I can a freon myself?? Can I use automotive freon??? I just need this to last the summer and I dont care if I ruin my landlords a/c unit? He thinks its broke anyhow. Thanks