379 pete a/c problems

Proper amount and type of refrigerant? The A/C might be working ok and it is something else, the inlet line to the compressor should get cold to the touch. The outlet line should be hot. All the magic happens at the expansion valve and evaporator. It may be plugged. Your temp blend door may be stuck on hot, shut your heater core taps off if you have them. If you have a blockage you will usually have higher high side pressure and lower low side than the numbers you provide. The High side is usually a bit higher than that unless the fan is on. If it everything is looking ok try a new expansion valve or orfice tube, whatever your truck has.

 

you vaccumed it good to start with?

 

How is your comment worth a "Thanks" and mine is not? I am getting a little annoyed spending my time helping people here and not seeing too many "thanks" in return!

 

Thanks Diesel Dave!

 

Peterbilts were notorious with plugging up the orifice screen. Your hi-side pressure isn't high enough and may still be low on freon. If you did not measure the freon according to the outside temperature you may still be low. The adverse side with the new FREON is overcharging. It will cause the same results. If you can't get an acurate measurement get a thermometer and put tit in the dash air duct he freon in slowly until you get temp. That is the cheater method.

 

Well, as long you are properly charging it, with those readings I would say your compressor is bad.

 

what kind of mileage do ya get with that puppy