I have heard that the lines and cores should be flushed with alcohol?

I am ordering new O-ring seals, schrader valve, and heavy duty orifice.

Is it ok to reuse the receiver / dryer? From what little I know about AC there is a dessicant sac in there that can get saturated with moisture. Will this moisture be cleared by the alcohol flush and the application of vacuum (I've heard you should let the vac pump run for an hour to get rid of the moisture.)

On top of this, as per my previous AC post, does anyone know a good AC guy in Los Angeles?

 

no.... you have to flush the system with either an A/C flushing agent or products such as Mineral Sprits, Hecat Safe Flush and Paint Thinner. Careful with Paint Thinner for obvious reasons. Helping to get the flushing agents through the system components are the Mastercool Flush Gun Kit. and yes you have to replace both receiver and dryer, just before putting the system into a vacuum. take it down to 15", then turn off the pump. and the guage valves. come back in about 15 min. to see if you lost any vacuum. if so you need to find the leak(s). then when you have found and fixed all system leaks. take the system down to 15" vacuum. for at least 15 min. with a system that has been open i would do it for at least an hour. then charge the system with the recommended coolant. ie r-12 or r-134a. but if you want the system to really cool, use the following.
Duracool®.com 2004 - Duracool® is The Recognized Leader In Hydrocarbon Refrigerant Technology
or
Environmentally Friendly Hydrocarbon Refrigerants HC-12a, HC-22a and HC-502a from Bennett Cycle & Supply

HC-12a® is designed as a drop-in replacement for ozone-depleting CFC R12 and global-warming HFC R134a refrigerant's compatible with both types of lubricants.

they provide better cooling and you use less coolant to charge the system, your system runs at lower pressures, thus the new compressor will last longer.

did i mention, that if your system is already discharged, you don't need a license to use these coolants, as they are not cfc/hfc based coolants.

 

You seem to know a lot about it, WIsh you were closer, I'd give you the business. Gives me some questions to ask when I visit a shop though.
Thanks!

 

My truck was a heat only truck when I bought it earlier this summer. I picked up the following pieces...

Engine side heater/ac box (with attached receiver/dryer and integral Evaporator)
AC lines.
Condensor and brackets.
Compressor.
Dash controls that have the AC positions.
The one piece of electrical harness that goes from the right fender harness plug to the high low switches and compressor clutch.

Took it into a shop today and had at it with them:

We flushed the system,
Replaced all the o-rings,
Replaced the orifice tube,
Replaced both schrader valves,
Hooked it up and ran it through a recovery cycle (nothing recovered as expected),
Pulled a vacuum and held it for a half hour,
Added 2lbs8oz of Freon(surprisingly there was an AC spec sticker on the radiator support even though it didn't come with AC from the factory)
Ran it for a while and it runs nice and cool.



On the way home I just had to stop here for a burrito. Seems the locals like the place......



Speaking of which, you wouldn't believe the kind of attention I pull down when driving by a home depot.... I don't dare slow down! (SoCal by the way)

 

I'm curious about the 15" of vacuum thing.... I thought it was pulled down to 29"? Not so? I'm sort of an amateur AC guy -- what I've learned has been from asking sometimes dumb questions and watching others...

 

I dont know about the vac. It was hooked up to an all in one machine. It recovered what it could. Pulled vac, then injected oil, added freon, all without removing any connections until it was all done.
Think I saw 18" of vac when it was doing it's thing? Not entirely sure though. It was all automated and had little intervention from us. It just beeped at the end of every step so we could push the continue button.
I didn't learn a lot, but I did learn that if I was going to do a lot of AC work, I'd want one of these machines.

 

These truck were designed to run with R134 ONLY.
Putting that substitute crap in there will only screw everything up.
That stuff was designed as a replacement for R-12 which is alleged to deplete the ozone layer.
All vehicles manufactured in 1993 and later are required to operate with R134 only.
And R134 is cheap enough to not bother with any other substitutes.

 

Go here,it should have all the info you need to be a certified mobile HVAC guy.Or be like myself and be a card carrying amateur
Mainstream Engineering Section 609 Manual

Mainstream Engineering Section 609 Manual

To answer your question

from the manual


For example, if liquid water in the system is initially at 80°F, then the saturation pressure of the water is 28.87 inches of mercury. Therefore, the vacuum pump must achieve a pressure below 28.87 inches of mercury (at the site of the water) for this liquid water to boil off (This is not the vacuum level required at the vacuum pump, it is the vacuum required at the water's location, the vacuum level at the vacuum pump must be even lower!), and at this temperature one pound of water vapor will occupy 1022 cubic feet of space.

 

10-4

I got a A/C certification card as well.