Thread: A/C comp deleted, now I want ot replace it.

Air powered? Don't know what that is. It's an electric powered vacuum pump.

Originally Posted by paedbo

Depending on what you decide to change, make sure you replace the high/low valves. You may check the system for a vacuum leak but you most of the time you have gauges connected so the shraeders condition goes untested until after your done

Do you mean the service valves? Where the gauges connect to the system?

Originally Posted by toof

Air powered? Don't know what that is. It's an electric powered vacuum pump.

instead of plugging it into a wall socket you plug it into an air hose. You need a good amount of air (about 5-7 scfm) and you should have a drier for the air compressor. It uses a Venturi to pull a vacuum. We use air operated vacuum sources in a variety of industrial applications, but they make them specifically for AC work too, I did one coworkers car two years ago when he replaced his compressor dryer and orifice tube. Did two last summer and about to do another, never had an issue with them they pull down to 28".

Jeff

Yes where the gauges connect, I'm sure if you have a massive compressor you can get away with a venturi vacuum pump. I've heard good and bad but really you need to get down to 400 microns or less for a decent dehydration of the system.

No pump that is available can pull that kind of vacuum. 29.5"Hg is the lowest you will ever get with even the best electric pump.

I'm not sure what you call a giant compressor but 5-7 SCFM is usually sufficient. That's usually about a 20 gallon 3 hp compressor which is in the range of any serious car guy. I use a 5hp 60 gallon which is larger than most home units but I have friends that have larger garage compressors.

400 microns (usually a measurement of length) in pressure comes out to .4 Torr or .0157"Hg @0*C

Jefr

I meant 400 micron rated pump or better. On a vehicle you'd be happy with anything under 1000 microns for the system. How many microns are vacuum pumps rated? Oh wait they dont rate them in microns I wonder why? It can be done with the air operated unit if one wishes. A micron guage is nice to have but for those of us who are licensed it makes sense. For the every day joes I guess venturi looks attractive.

Man as long as you can pull it down to between 28-30"Hg for an hour it's good to go. I live where the RH is in the 80-95% 6 months of the year. I used one on my Dads truck going on 6 years ago when we did an engine swap and it still blows 34-38 from the vents. Maybe it's EFS, in that case thanks a lot!

Jeff