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.

[john]

In addition to the diverter flaps, make sure your hot water shutoff valve is working.

[Wrenchbender Ret]

If the comp. kicks in grap the return hose or around the control valve. If the refrigerant system is working they will be cold. Check the vacuum hoses going to the system. Most of the deverters work off vacuum.