Any one have a recommendation on how much of a vacuum pump I would need to pull the vacuum on a York compressor? Could it be done with a hand pump? Or do I need something more substantial? What's the consequences of not pulling the vacuum on a compressor?

I'm switching out my compressor and would like to leave the system charged. The compressor is making some bad bad clanking/grinding noises under load but it cools nonetheless. Should I switch it now with the one I got from Pull and Save ($12.99) or wait until it locks up?

Thanks

 

[updated:LAST EDITED ON 02-Sep-02 AT 10:39 AM (EST)]In my opinion you will not be able to vacuum out the compressor with a hand pump. If you do not vacuum out the compressor, you will have entrapped air and moisture. The air will lower the efficiency of the system, as it just goes along for a ride with the refrigerant, and does no cooling or heat transfer. You will also have moisture, which will react with the refrigerant to form an acid. The acid will not do your system any good. It may cause your refrigerant to leak out.
For $20, you should be able to get your compressor evacuated. After switching compressors, you will be a little low on refrigerant, but it may still work.
You could rent a vacuum pump, and a set of gauges/manifold to hook up to your system.
Do one or the other, or buy a vacuum pump if you want the system to work well and last.
tom

p.s. Yorkies have a sump, so you should make sure that you get the right amount of oil added back to your 'newer' compressor. There were instructions in Motors manual for making a dip-stick to check the level. If you can do nothing else, at least drain the old compressor and add the drained amount plus a bit to the replacement compressor after draining it.

 

yes indeed pulling a vacuum is necessary. you will need a standard 3-5 cfm vacuum pump and a set of gauges. you may wish to wait until your old compressor locks down though. i'm running a york in my 74 e300 and it sounds the same way. from what i've been told thats the way they sound, but never the less. if the compressor has suction and dicharge line sevice valves like mine, all you have to do is run the service valves in when the when the system is off and pressures are equalized. then you may remove the service valves from the head of the compressor. when re-installing the service valves you will need new gaskets or o-rings depending on whether you truck came w/ factory or dealer air. make sure to lubricate seals w/ refrigeration oil. now your ready to pull a vacuum. since your service valves are front-seated you should be able to pull a vacuum on the head of the compressor by itself through the gauge ports. 30min.-1hr. should be plenty as long as long as your in a deep vacuum (30in.- or 400 or less microns.) also if you have not converted your system to 134a i personally recomend using rb-276 (90% charge) which can be purchased in r-12 size cans at you local HVAC supply house. i personally use this refrigerant all the time in commercial refrigeration applications as a drop in replacement for 12 it is especially nice in cars cause it runs a lower head pressure. anyhow let me know if any of this helps.

chris