heater core bypass

OK I have a question. Apparently I have a leak of hot air into my ac system not allowing my ac to fully cool the cabin. I know I can put a T in between the 2 hoses and bypass the heater core. What I am wondering is, what is the fix for this? Do you just have to take the time to bypass it each year? Or is there some way to fix all the air leaks? Probably just needs new gaskets everywhere. Where can those be found? Anyone had any experience with this?
Thanks
Greg

if your getting hot air when the ac is on that means the valve that controls the flow of hot coolant is bad and probally should be replaced

mine does something similar. My truck does not have AC,but I cannot adjust the temperature control. I can set the temp control right cold,or right hot and it just blows out a constant heat. It's kind of annoying having only heat in the summer ride...

This problem arised when I put a new dash in,so maybe I messed something up with the controls when reinstalling everything?

I haven't been able to completely verify this yet but the temp control dial has a stud or key on the bottom. That key fits in the slot in the dash. Over time that key breaks. I got another one from ebay and it had the key broken too. I tried putting a screw in it to see if it would hold...it pulled out. That's what I think is going on with those things.

yeah,cuz i cant adjust my temp at all and i've used 2 different temp control switches. the cable fits into the piece that moves when you rotate the dial and the entire cable moves down to the heater core,but no difference in temperature. Just hot.