The A/C service port is on the accumulator (Filter/Seperator i think is what you called it)on your Silverado. Good luck and keep me posted. Be glad to help.
It's common to have very slow leaks from the seals, the most common seal to go is the one on the compressor. If your charge last for one year, you can sleep at night and always check the a/c before the winter so the seals always have oil from the R134a to keep them from getting dry. And yes the service port to the low side is smaller then the high side. Keep cool friend.Â
Note your static pressure to the line should be 80 to 105 PSI depending on the outside temperature (a/c off), and normal reading with the fan and a/c on max should be 25-35 psi and the high side 200-350psi. Keep cool friend.Â
What is your high side readings??? When the compressor clutch is definitely engaged and the low side is high and the high side is low, the most likely cause is that the compressor is failing - it is not pumping sufficiently. Rarely an AC clutch could be slipping but usually this will be accompanied with a squeal or chirp. Also be sure not to overlook the obvious, like a loose belt!--- When the low side goes so low that it’s reading shows it is in a vacuum, the most likely cause is a bad expansion valve or blocked orifice tube. Another possibility is a restricted condenser. Blocked condensers are not as common as they used to be but if a compressor fails and comes apart inside the remnants can end up in the condenser causing it to restrict the flow of refrigerant.----If both low and high side readings are too high, this indicates an overcharged system - too much refrigerant. This also can indicate that the condenser fan is not working, is too slow or the car is overheating and heat is transferring from the radiator to the condenser.---Both low and high side readings are lower than normal, this indicates a cars AC system is low on refrigerant and is under-charged  I hope this helps friend, keep me posted and i hope the system is not over charged. Over charged system also give's  a poor a/c performance.Â
×
564 views
Usually answered in minutes!
Thanks. There is a small service fitting and a larger service fitting both in the same (smaller line going to the accumulator). Looks like what may be a pressure sensor on the accumulator it'self. Sorry about my ignorance to automotive terminology. My experience was with large 400-600 ton R22 units. Thanks for any help. I'm sure of the fact I do have a very small high pressure leak. Thanks again.
Thanks emissionwiz. Very true about 'freon'. Does refrigerant 134a work better? Thanks again. I always value any help.
Thank you again my new found friend. I'll add some 134a tomorrow. I knew the fittings were different sizes but I needed someone to keep me straight on the subject. No experience at all with 134a till now. I discovered this site today and already "hooked on it". I'll let you know how it turns out. Gene
I think I may have a 'bigger' problem unless the pressure guage is inaccurate. Ambient temp around 80 F. With unit set to Max AC the low pressure only comes down to 65-70 before the compresser cycles off again which is only about one minute. Is that enough time for the low pressure to pull down? Note, when cruising down the highway it's very cold. My copilot takes the control and turns AC to low. Thanks again. Gene
Molson---U R on target !!! It appears like a restriction. It seems to be the (here's the wrong terminology again) orifice between the high and low pressure service ports clogged. Both pressures are high. I'll know for sure later today. Leaving soon to drop it off at the shop for repairs. Thanks again for all your help. Now if you could just help us out with some cooler weather here in south Georgia----tripple digit temps have been here a week. Gene
this car doesn't use Freon.
×