A/C blows hot - think I know the problem but need advice

[calgary72]

On my 72 SWB 4x4, my A/C blows hot and it won't divert to the defroster either. When I move the temp lever to cold I hear the compressor kick in but I still get hot air from the vents. I believe I have issues with the diverter flaps so I was going to take it apart and see if I can replace the gaskets and maybe fix the flaps. My question is, can I take apart the heater/a/c box on the firewall without having to depressure the coolant?

BoobyK has a great photo record of a rebuild of an a/c system.

http://public.fotki.com/blazbk/blaze...d_of_ac_syste/

I borrowed the followng pictures off his build to show what I mean. I hope you don't mind, Mr. Bobbyk. I just want to understand what I have to deal with before I prepare myself to attack the problem.

I bought the truck on a cold day in the spring in Saskatchewan (I didn't check if the a/c was working) and the guy I bought it from said he would have his 'a/c guy' look at it and make sure the a/c was working before he shipped me the truck. Well, that was BS but I have the truck anyway.

Any advice on how to get at the problem would be appreciated. I was going to start taking apart all the duct work inside and then take the heater assembly off the firewall to get at the flaps. I don't want to start something that I may not be able to finish.

I am less concerned about whether the a/c is really cold but rather that the heat will shut off. I can deal with that later and being in the great white north, cold a/c is less important most of the year.

NOTE: See above. These are not my photos. Just want to show what I am referring to.