I have a 90' and 91' 740 I am going to convert to R134a since my stash of R12 cans is down to 1 left. The 91' took 3 cans last year. The 90' AC doesn't work and the system may be contaminated (just bought the car). I have spent hours reading info. on this BB and others and need more info. Since I have 2 cars to do, I feel I can justify the cost of a Robinair 4CFM vacuum pump and figure I can resell it on ebay when I'm done. I have the Volvo conversion kits I need. I also want to buy a manifold and hoses, preferably a universal type which I can use every 5 years when I need to add R22 to my home AC (I think I'll take the online MAC test so I can buy R22). Now for the questions:

1) How do I go about hooking up the pump and manifold and what is the procedure for drawing down the system and sucking in the R134a? I would also like to monitor the high pressure side so I can periodically recharge the system, if needed, and add more R134a. I gather that it is hard to do a correct recharge if you don't monitor both low pressure and high pressure. If too complex, is there is some info. online that explains this? Please give me a link.

2) I see many universal manifold sets (R12, R22, and R134a)on ebay, but most have 1/4 inch connectors and automobiles use 1/2 inch ACME. Is it okay to buy one of these with 1/4 inch connectors and buy adapters or should I just buy one for automobiles? Like I mentioned earlier, I'd like to do my house also when necessary.

3) How do I do leak detection if, when I draw down the system, the system won't hold a vacuum? Do I have to charge it with 134a and dye to find the leak and if so can I open the system, fix the leak, and pump it down again or do I have to change the receiver dryer again.

4) Should I use Nylog on the O-rings for a better seal? They are advertised at http://www.ackits.com/index.cfm?fuseaction=Nylog

Thanks in advance. 83' 245, 90' 740, 91' 740, and 95' 940

This board is one of the good reasons I find to drive Volvos!