[rusnak]

[QUOTE]Originally posted by kuehl

Originally posted by rusnak
Kuehl, thank you for the advice. 3 hours though? Won't my residential hobbyist type of pump overheat? What if it turns off to protect itself, do I try to shut the valves and then re-start the evacuation?

Well if you don't trust your pump then don't trust your pump. Heck, if you are concerned about leaving it running then just invite the gals over for a few hands of gin, or glasses, or whatever and babysit the pump. My concern with pumps is more related to temperature and oil viscosity.
Leave a pump running outside in the sun on a warm day and you'll figure it out.

You can evacuate for less time if you wish, however our experience tells us 3 hours (running).

There are a few good brands out there, SPX RockinRobinair is one. And there is a lot of inexpensive "stuff" being imported from various countries that have yet to have to deal with customer returns. I purchased a Robin a few years ago over the counter from our local supply shop and it started getting noisy after 4 hours. They replaced it, no questions asked after I let them listen to on the speaker phone; swapped it out the same day, so I have no problem spending a few extra dollars for an item with a warranty. I would not suggest Walmart, at least not yet.


Also, I thought I'd clarify for those running R-12 that the pressures for 134a are significantly higher, which is why most people upgrade their pump to an ND, Seiko, or other rotary pump when they switch to 134a.

Yes and no. Pressures, we already know about, are higher with a stock system, especially if you overcharge using small cans rather than using P&T's. Most of us replace the old Yorks because either:
A) they vibrate too much
B) the service valves leak
C) they weigh too much, take up too much room
D) not economical to rebuild
E) less efficient than new styles
F) attaching R134a charge port adapters to them is not fun any more.
G) should I stop here?

You must be a joy to deal with as a vendor. Or as a customer. I wouldn't really know.