What kind of vacuum pump required for A/C evacuation?
 

How powerful of a pump is required for a regular r134a system such as that in the 94 e320 (w124)?

Would a 1/2 hp model be adequate?

I have the opportunity to buy a Duo Seal Mo. 1402 at a reasonable price and want to make sure that I could use it for A/C system evacuation.\

I found an eBay auction for the same model indicating it could draw 29.9 inHg is this adequate?

Thanks!

I think what is more important is the particle size it will remove. Like down to 25 mircons is real good. Also CFM is another rating, that has to do with how fast it will vacuum system which is not real important to most people.

I am not familiar with that specific model and brand, but if it has a 1/4" inverted flare for a/c work and will pull to 29.9" it sounds plenty good. Buying a used pump might be risky. If they have sucked a bunch of contamination into them and have not kept the oil changed they might not work very well.

Good luck,

Thanks for the advice, I'll keep that in mind.