A person who is going to regas my aircon said he doesn't add oil unless I have had the compressor overhauled before the regas. He says the old oil would still be there in the compressors sump.

Now I'm wondering

1. Since he is going to use a vacuum pump to evac the system, wouldn't most of the oil be sucked out, requiring new oil to be poored in anyway?

2. Does my compressor even have a sump? This is the first time I hear of him mentioning compressor sumps. I have a Nippon Denso 10PA Compressor from a Toyota, similar to this one :

http://www.alibaba.com/product-gs/23...mpressors.html

So I don't know whether it's safe to let him just put gas in the system, because my thinking tells me during the evacuation proccess most of the oil would be removed.

Thanks.