AC reinstall

Build has changed again. Engine is almost done, short block scheduled to go together tomorrow. Kept the iron heads, ported them according to The Mad Porter's instructions. Had a custom cam ground by Delta, per PPAM's specs. Going with an Eddy Performer intake (2166) and either a Holley 1850 or 3310. Decided to reinstall the ac with the factory brackets, question is this: does anyone have a diagram of the bracket placement on a 460 specific to our trucks? I might have to go off memory but I want to make sure I am doing this right. Also, AC system is obviously completely empty as it is in many pieces right now. Second question: the only fluid specs I can find are for R12. What weight PAG oil should I use and how much? I've never done AC work before so I also don't know how to put in. Seems I can take anything apart, but putting back together is WAY different!

Did you change your accumulator to the newer one for R134A?

 Thats a good question but no, I don't think so. The system was swapped before I got the truck. Pretty sad that I have to ask this, being that I sell parts for a living, but where do you get one of those? I never knew that you had to change the drier for r134a.

Or wait, is it just one from a post-94 truck?

Ya and you have to change out the clutch cycle switch to work with the newer dryer. Check your hose fittings too because I think there were a couple of different outlets on the dryers depending on the model year.

Thanks Chad, so just to get this exactly right: I need a drier and cycle switch from about a 94-95 truck, right?

Essentially. There might be some more options if you want spring lock fittings I think. Specifically what you are looking for is a drier with a 12mm clutch cycle switch outlet. I was actually using one from a Ford Probe at one point (because who doesn’t want a little Probe in there every once in a while hahaha). Are you using a factory style compressor with the manifold style fittings? If not don’t bother with stock style hoses.

Yes, everything is factory. I'm going back to the factory v-belt setup, so I'm using the original compressor.

Thinking about it more, the ac worked fine in this truck before I dismantled it, I think what I will do is just put it back together and fill it. Only problem is: how much oil and what weight?

If you have a complete system and it has been open you need to change out the drier.
You can replace it for the same year as the truck as it will bolt right in.

As for the switch they do say to replace it or adjust the one you have to work with the higher PSI that the 134a runs at.
Now I replaced mine and it went bad with in a year.
Also in checking even being for a 134 system had the same cut off / on psi as my 81 switch.
Also on the adjusting if you look at the plug end the screw is reverse from a normal screw driver so I dont know how you can turn it?
At this time because the "134a" switch is bad I got it jumped out so the AC will work as it gets really really hot here!

You should also replace all the O-rings that work with 134a.
I also replaced all hoses but 1 as I could not find it but I also seen posted you dont have to replace the hoses because of the R12 oil has sealed them. So take it for what it is worth.
I also installed a new condenser as the old was bad.

Now for oil I forget what I used or how much at this time.
The first time I think I added to much as it did not cool too good.
I had issues with leaks, fittings not tight, used compressor went bad just a mess to get the system going.
When the compressor went bad I changed out the drier again (it was new to start) and flushed the whole system with AC flush.

Now that I have the system sealed, new compressor, hoses, condenser, drier, pilot tube and charged to 80% of the R12 it cools pretty good.
Dave ----

Thanks for the advice. I took a look at my components and I just don't think it will be worth the cost. However, now I'm looking at doing something I've wanted to do for a long time: on board air. So let's start a new thread!