Which vacuum pumps pull down 500 microns?

[Paul Heiser]

I'm starting out getting my ASE 609 and buying the quality equipment (affordably).

I was looking at some used pumps:

REFCO single piston.
Appiaon G5 Twin Piston
Vevor 1/2 HP

I also was considering the Harbor Freight pump. It's 3 CFM for $150, but I don't think it gets anywhere close to 500 micron.

Thanks

[tony1963]

I use all CPSI equipment, except for a Mastercool recovery machine that I gave away due to it being junk. The CPSI pump does quite well.

[tbirdtbird]

I had a Robinair, but it crapped out waay earlier than I think it should have. I now have a JB Eliminator, very happy with it

[Paul Heiser]

What I mean is how many Horse Power, how many pistons, CFM ratings and things like that.

Because I'm looking to spend the least right now on a used pump for auto ac services in my mobile mechanic business, and later this year get a Fieldpiece pump. So I don't know if the used ones I'm looking at are strong enough or not. I think they'll work though for at least a month or two...maybe even slowly, but I don't know about strength.

[tbirdtbird]

I would google for a 3 cfm pump and see what comes up. Below that, evacuation will take forever. I think most pumps are 1/2 HP. I would not worry about that tho. Your questions are can I get a 2 stage 3 cfm pump for the price I want.
A single stage pump will take even longer. Since time is money, you have to weigh these things for yourself. If it takes you 2 hrs to evacuate a car, what other work could you have been doing in that 2 hrs, unless you only work on one car at a time.

Remember, the most important thing to do to your pump is to CHANGE the oil. It makes a huge difference. Oil that is saturated with water vapor will not get you a good vacuum.

Fieldpiece makes really good stuff but man o man are you gonna pay. FWIW JB industries (JB) makes very good quality at better prices.

Then consider getting a good quality vacuum gauge. Most shops just slap the pump on there for an hr or less and call it good. Clearly, the better the vacuum, the better the system will work. It can be hard to get below 1000 microns, especially if the system already has oil in it and refrigerant residues dissolved in the oil. If you cannot get below 1500 microns to me there is no sense in charging the system. 500 is the stated ideal, but that is hard to achieve. Few automotive shops use a micron gauge. But I also do domestic, and I want that micron reading. There are several ways to set up a vacuum tree for your manifold gauge set. I posted a pic of how I set mine up about a yr ago.
You will want independently controlled valves for the pump, the gauge, and the bottle. Do not subject a gauge to pressure.

You might inquire with Tim, the site owner, ackits.com, to see if he has a vac pump available. His prices are usually decent.

[tony1963]

I will agree with the above statement, but I would recommend CPSI hands down. Whatever you do, avoid Mastercraft as those units are junk.

Even if they pay you to take it, leave it on the shelf.

[Paul Heiser]

Okay, thanks.

I researched everything AC for about 72 solid hours. I'm getting the 609 and all, so that I'm doing legit work on people's assets.

I bought a JB 4 port manifold from TruTechTools and a Fieldpiece micron guage to be sure I'm at least getting through this summer with clean seals and contents in the system.

What did you mean by "don't subject the gauges to pressure" in your last post?

[tbirdtbird]

Sry, should have read don't subject a vacuum gauge to pressure.

[Tim]

Santech makes good stuff. I had a guy at Mastercool once tell me. All pump ratings are achieved in laboratory testing. Not real-world use, like 105 degrees during a monsoon season.


43-MT1721

[Paul Heiser]

So only open up the micron gauge to vacuum not pressure. Is that right?