Great deal on Robinair 34970 at ToolTopia.com Not necessarily this particular one or brand, just in general: Does this type of air compressor driven vacuum pump actually work? Or am I better off spending the $150 and getting one driven by an electric motor?

I need to evacuate the AC system I am installing on an F100.

Any opinions?

 

I have the same model on my service truck, and it works just fine!

 

I bought one of those when I first did my A/C, but my air compressor was too small to use it. So I just kept an eye on the Tadd Wholesale ebay store and kept on bidding on the electric ones until I won one for the price I wanted (cheap!!!). Apparently they are a reseller of Harbor Freight stuff that gets returned?? That's what it looks like to me anyway.

Here's one that has a day and a half left on it.
2.5 CFM VACUUM PUMP 115 VOLTS 60 Hz, 1/6 HP, 1720 RPM | eBay

I'm sure the other kind will work great if you have a big enough compressor to run it.

 

I have used both kinds and the air driven ones won't get more that 20" of vaccuum but that is enough usually. I evac the system 2 or 3 times and that should be plenty. if you get the electric one it will pull 30" of vaccuum and that is better but not required. I would say get the air powered one and go for it mine works fine and it is really easy and simple to use. As a matter of fact you could build your own with a few fittings. All those air driven pumps are is a ventury that the air passing through a fitting creates. If you get a "T" Fitting and a valve and blow air through the T it should make vaccuum in the third leg of the T and if it doesn't then put a restrictor in the air supply before the T and it will pull vaccuum then.