AC in front, not in rear?

Joeglia

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1998 Montana - I replaced the compressor and condensor. Recharged system with r134a refrigerant. I have cold air up front but the rear AC is not cold at all. I do hear the rear blower running and air(hot) is coming out so to me these rules out a duct but is there a vacuum control/damper in the rear that blends air hot & cold? Thanks
 
did you evacuate the system and recharge using gauges?
 
I did vacuum down the system for 20 minutes and let it sit for about 45 minutes. There was no sign of a vacuum leak, so I then vaccumed down the system for about 45 minutes. From your previous information you sent the system takes 2.90LBS of refrigerant which was "almost" 4 x 12 oz cans. So I did put them in but I put them in via a small blue tube direct to the low pressure side and not via the set of gauges I have. Did I do something incorrectly?
 
if you have gauges it would be a good idea to check the system using them to verify the system is fully charged
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I do have a set of gauges and will test the charge on the system. Is there a danger in overcharging with refrigerant, as I know I put in an amount just shy of what it calls for by OZ in weight not fluid ounces? If I recall correctly, the charge will depend on the outside temperature at the time I am charging.
 
a slight amount over shouldnt make that much of a difference, I was leaning towards a possible undercharge based on your problem
 
Replace the rear a/c expansion valve. If the rear valve is stuck wide open, you will not be able to get a good high side pressure reading, nor will you get the rear to cool. If the rear valve is stuck open, then the high side pressure will bleed off to the low side at the rear.

You have to drain the system and then open the back and replace the rear a/c expansion valve. You must disconnect the lines under car to do this. Then recharge system.

By the way, spend $60 at Harbor Freight and get yourself an automotive a/c manifold set to properly diagnose the a/c system.
 
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