AC R134a Retrofit

Ok, I got my AC working today and the vent temps are to warm.
It was 101 degrees with 40% humidity today and my vent temps are 75 degrees. Are these temps about normal or should it be cooler?
What I've done so far is a new condenser, new drier. new expansion valve,
resealed the compressor, remove the EPR valve, full system flush and all new o rings. Vacuumed it down to 29" for 45 minutes, filled it so i have 40 lbs pressure on the low side at 1200 rpm. The high side is about 250 psi.
What did I do wrong, and can it be improved on?

Wow you went the full meal deal. Keep in mind, 134a in a r12 system get filled no more than 80% capacity.

That's a 26° ∂T from ambient. Not bad, but you should be able to do better. What kind of condenser did you install? Stock type, or parallel-flow (manifold type)? What kind of fan are you running? Do you have a fan shroud? What have you done regarding roof/door/floor insulation and window tinting?

If you charged until you saw 40 pounds on the low side, it's likely the system is not properly charged. It's best to charge by weight. Charging by pressure can successfully be done but really only if you're very experienced and know exactly what you're watching for on the gauges -- it's not just any particular magic number.

You removed the EPR valve, good. But if you didn't install a clutch cycling switch, that's bad; it means your evaporator will freeze up with condensed water and system performance will drop way off.

Not enough charge .. you have to charge by weight. You then will have a better ideal of where you stand

I have a 7 blade clutch fan with a shroud and the condensor is a stock type
two row. I didn't add any insulation to the cabin but it is a factory AC car so it has tinted glass.
I thought A bodys came with a cycling switch installed from the factory.
I have 60 psi on the low side at idle and the 40 psi at 1200 rpm. I didn't want to overfill it and have to high pressure readings.
Is there a difference in the type of 134? I just used Autozone 12 oz cans.
Thanks for the help.

Autozone 12oz cans may only be 8 oz refrigerant and 4oz stop leak or dye. Your system should spec out weight of R12 on a sticker and then fill it to 80% of R134.

pishta said:

Autozone 12oz cans may only be 8 oz refrigerant and 4oz stop leak or dye. Your system should spec out weight of R12 on a sticker and then fill it to 80% of R134.

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Not sure what year car you have but my 72 required 2lbs, and only 2 lbs, no more, no less

bobscuda67 said:

I have a 7 blade clutch fan with a shroud

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Should be adequate.

and the condensor is a stock type
two row.

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That was an error. The main performance choke point in the system is effective condenser heat rejection capacity, even with R12. R134a needs more condenser heat rejection capacity than R12 for a given level of system performance. You'll be able to get much better performance out of the system if you put in a parallel-flow condenser -- the biggest one that will fit the cutout in the radiator support. They have much greater effective heat rejection capacity for any given condenser size.

I didn't add any insulation to the cabin

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You'll want to, otherwise you're trying to cool a solar oven and you will fail no matter how good the A/C system is.

but it is a factory AC car so it has tinted glass

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You'll want real/effective tinting. Not the cheap purple garbage -- I'm talking about the films from the likes of Llumar. It doesn't have to be dark tint, either; the newer films reflect a lot of heat while letting through a lot of light.
.

I thought A bodys came with a cycling switch installed from the factory.

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Yes, systems through '73 have a clutch cycling switch and systems '74-up have an EPR valve. You mentioned removing the EPR valve so I guessed you were working with a '74 + system. If your stock clutch cycling switch is hooked up and working, you're all set.

Is there a difference in the type of 134?

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No, R134a is R134a. But as the others say, make sure you are buying pure R134a, not a "stop leak" or other blended product.

I put some dye in the compressor Sunday and didn't see any leaks. Looked at it today and there was dye all over the head of the compressor. So i took off the head and the plate and ther was rust on the gasket surface on the head, plate and the compressor body. The seal was broken and leaking.
How can I keep them from rusting again? And where can I get just the gaskets? I think I can reuse the drier or should I get a new one?

Most parts stores don't handle ac compressor parts. No-one seems to repair them nowdays. Check with NAPA or online for gaskets. The drier should be replaced if the system is open for an hour or more. Pulling a vacuum for an hour + may save a exposed drier but the descant in the drier will still contain moisture after a vac if the system has been opened for too long. tmm