I am converting my 93 f150 to 134. So far i have purchased a new accumlator(because you should), compressor(leaking oil), and replaced the 2 in 1 line from the compressor to the evap and to the condensor(dry rotted). I was checking on the ford web site and i have a blue or red orfice option. Whats the difference?? what one is better to use with 134?? Also after i flush the parts of the system i havent replaced how much oil should be put into the system??

 

It sounds like you're being thorough and doing it right.

Use the red tube (.062" orifice) with R134a.
You really wouldn't notice much difference with the blue tube, but the 94's came with the red tube and R134a. That's the only functional difference in the 2 systems.

You'll want to use the oil capacity shown on the underhood sticker. Probably 8 ounces.

To be sure of 100% from your conversion, replace the fan clutch if it's more than 6-8 years old. The first place they get weak is at idle and low speeds. You won't feel a difference with your hands, but the loss can severely effect the AC performance. Use a Hayden or Motorcraft unit, the more generic clutches fall short at low speeds.

Good Luck

PS. Make sure there is an oring on the low pressure switch fitting. Sometimes new accumulators don't have one and it's really easy not to notice. I've been bitten a couple of times.