Changing out Compressor for AC

Ok I say it been a while since I have done this... I do remember oil needs to be put in the Compressor.. Not just for a Windstar but other types as well... This is what my problem is.. I am changing out a compressor and dryer,filter and orings.. The problem is I cant remember if I add oil to the compressor or if they did it when they added freon and pulled the vac... Can anyone help refresh my memory.. Thanks for any help.. Gary

Gary:

I'm not totally clear on your question, but it sounds like you want to know if you need to add any oil, given the task at hand.

I did a lot of reading at the start of this summer because I retrofitted an older R-12 system with R-134a. I wanted to make sure I did it right, so I spent a fair amount of time collecting information before I started.

From what I've read, the only danger in putting in too much oil is that the oil takes up a certain amount of volume in the A/C system, thereby reducing the amount of refrigerant capacity of the system. However, the danger of tool little oil is that the pump will run without lubricant, which of course is very, very bad.

I've read that anytime you replace a pump, dryer/accumulator, there will be a significant amount of oil removed with the components that needs to be replaced. I don't know the figures, but I've seen them given. I've also read that the refrigerant carries a certain amount of oil in it as well, and if a catestrophic leak has occured, it will carry out some of the oil.

I believe that pumps can come either with a charge in them or not. You should drain the oil from the original pump into a measuring cup, then remove any oil in the new pump and measure the same amount back into the new pump. I think you can do the same with the other components.

Another approach you might consider is to fully flush the condensor and both evaporators (if you have the rear A/C option), then put a full charge of new oil in the system. I did this using a combination of mineral spirits and wood alchohol (methanol) on my R-12 system since the original oil was mineral oil. I'm not sure, but you might be able to use the same flush on a system that is charged with PAG oil.

Tom

Hey thanks for your reply... I think you cleared what I needed up.. So if the compressor does come with oil I will remove the excess.. I am fearing how ever the compressor has a hole in it.. So Maybe the oil came out.. Wont know until I remove it.. But I will replace for good measure at what i think it should run. I will have to take it to the shop to have them recharge it and will give them my info on what i have done and let them check it for leaks.. So if they can flush the system that may be the better option and let them replace whats needed.. I assume I could do this.. Just wanted to know will the compressor needs oil until it get to the shop. Just did not want to run dry until they get it.. Of course the AC would not be engaged until freon is added.. I was trying to think of the last time i replaced a compressor.. Been a while. But don't remember any issues.. Something about the oil clicked in.. So I just wanted to know if I need oil in it to get it to the shop.. Thanks for your reply..

While you drive from your home to the shop.....unplug the electrical connection to the compressor clutch....
Make sure the wire is secured so that it will not dangle and get caught up in the belt.
THIS will prevent the A/C compressor from running on the way to the shop.
Don't forget to plug it back in when you get to the shop.

I did this when my A/C system leaked a couple years ago......until I got it to the shop.......so that it would not cycle on and off.......which it does when you select any defrost setting on the dashboard.

I agree that it's a very bad idea to run an A/C without a charge. No refrigerent means no lubrication.

I don't know about the Windstar, but when my Chevy lost it's charge the system sensed this and would no longer engage the clutch. There is a pressure senstive switch that shuts down the A/C if the pressure in the lines is not above some minimum (something greater than ambient pressure, probably 30-40 psi). I don't know if the switch was normally open or normally closed. I guess unplugging the clutch will be a fail safe measure.

TomJ

You don't say what year your Windstar is, but the spec decal underhood may say how much oil should be in the ac system. I think my 95 does. It is good to empty each component to measure what is in it but a leaky system will not have it's full amount. To get all of the oil out of the old accum/drier is to drill a large hole in it's bottom. I think the autozone.com repair section covers this if I'm not mistaken. I'd think if a new commpressor comes with oil in it, it would specify how much so you're not guessing how much is in it, though you could pour it out and measure it, but I doubt it has all the oil in it needed for the entire system. I came across a product that I think cleans and flushes out your system at AA and or AZ. I think it requires compressed air. It eliminates the need for the vacuum step.

Thanks for all the info.. 2002.. I am doing... IF the oil is still in it then i will add as much or just about as much that comes out.. The shop is only a half mile up the road.. I just did not know if i needed to add it or they would get it all out when they vac out the system and add more..Just been a while since i done one could not remember..