Got my a/c working but have ???

[chevydog66]

I have a 01 6.0 dbc with the Sanden 508 comp., Dirty Dingo bracket, new American Autowire harness, and Old Air Products POA update kit, new receiver/dryer. All new orings oiled up too. Had it vacced and pressure checked, charged with 1lb 10oz. of R134 and 3 oz of low viscosity pag oil and dye installed. It blows somewhat cold but not as cold as I'd like it to. Any suggestions?

[truckdude239]

What are the pressures when using a set of ac gauges? Low side should be between 35-45 on low and 150-250 on high side. Sounds like you dont have enough freon. Also are you running a r134 condesor or the r12 one.
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[chevydog66]

Yes, I have a R134 condensor. Low pressure side was at 48-49 psi. I don't remember what high side was.

[truckdude239]

Sounds like its over charged then. R134 wont cool if over charged either
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[ls1nova71]

How big is the condenser? Do you have good airflow going through it (and not around it)? Is the compressor cycling?

[chevydog66]

I was thinking maybe over or undercharged. Would overcharged be a higher pressure and under be a lower pressure?

[chevydog66]

The condensor is the stock replacement for the truck, it's about 5 years old. A/c was functioning 4 years ago when I had a sbc and Sanden comp. in it. The compressor is not cycling. I have the stock fan shroud for the truck and am using the 6.0 clutch fan, it's a tight fit.

[truckdude239]

I mean its a toss up not enough air flow will jack the head pressures up causeing it not to cool get you a good strong box fan and sit it in f ront of the rad and condenser and see if that helps thats what we do at work to check an air flow problem
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[chevydog66]

Cruising at 40-50 mph helped a little but my friend that vacced and charged it said he normally sees around 50 psi on low side on the newer stuff.
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[vannatta20]

I would lower pull some of the refrigerant out. put a thermometer in the vent and slowly add more until temps get to around 40 degrees. My system needed about 2 and a half 12 ounce cans. It was all custom a/c system.

[Blackpony]

I used all the factory components in my ls swap except the compressor and lines, i recharged it with the factory recommended amount and it blows ice cold. Wanting to say the pressure was close to 50 on the low side also. I spoke to an ac guy and he told me that with the 100* days we see here in tx, it is normal to see around 50 lbs on the low side.. hope this helps

[chevydog66]

Originally Posted by Blackpony

I used all the factory components in my ls swap except the compressor and lines, i recharged it with the factory recommended amount and it blows ice cold. Wanting to say the pressure was close to 50 on the low side also. I spoke to an ac guy and he told me that with the 100* days we see here in tx, it is normal to see around 50 lbs on the low side.. hope this helps

What is the factory recommended amount? Thanks.
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[dkauffman05]

Same problem I'm having with a sd7 compressor. I'm getting about 55 degree vent temps cursing around . It's hot and humid around here also.
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[chevydog66]

I found a small leak between the 2 nuts on the expansion valve. Is there a o ring in there? Also I think I need to bend up some aluminium to duct the air better between the condensor and radiator.
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[Blackpony]

I put 2.75 lbs in mine or about 3.5 cans.
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[ChevyCruizer]

You need to know the low and high side pressures to really know if it is over or under charged. Also the pressure varies a lot depending upon ambient temp. I cant get to google images, the dang work server blocks it, otherwise I would post a chart for you.

Also, if you are using factory specs for the freon amount you need to use 80% of that for 134, generally speaking. That should get you close on most conversions.