Air Conditioning A/C Questions

[bagoon316]

Alright, so I did my compressor last year, with a new drier, and never had it properly vacuumed and cycled through on the refill, and it eventually blew a couple months down the line.

I have a few questions I'd like to ask some of you A/C tech guys on here.

Items I have purchased just reading through some threads and taking notes:
-AC Compressor
-Drier/Receiver
-Expansion Valve

First question: Should I also replace the Condenser and Evap Core? The condenser is easy, and the evap core will be out when I do the expansion valve. Both parts will run me about another $200 total...

Second: As long as I just install the parts, and bring it to an A/C tech shop, all I need them to do is cycle/vacuum the system, and fill with oil and refrigerant and I should be good? Correct?

Third: Is the PAG Oil different than the oil they will use when charging the system? The compressor will most likely have oil in it, and I am not sure how much is supposed to be in it. Do I leave it? Drain it? Add correct amount? If so, how much is that?

I appreciate all the help, and any tips/tricks, etc. Any advice on proper install and all that is golden/helpful. Thanks!!

 

[xci.ed6]

Flush the condenser & evaporator, there is a special chemical for this. I can't remember if the evap is a parallel or series flow, but basically...

series is one long tube wound back and forth, easy to flush.

parallel, two tanks connected by a bunch of tubes. can not flush

if you get any metal out of a parallel flow, replace it. No matter how long you flush it there will be metal hiding somewhere.

As for oil, I don't trust aftermarket compressors. I always drain them completely before installing, then refill with the spec amount (in the FSM) of the spec PAG # (in the FSM). Just pour it in. You can refill all of the parts like this, but if you do not remove the condenser & evap, it's pretty much impossible to pour it in, so you can add the difference between the total capacity, and what you added directly, through the low side port during service. Just tell the shop how much (they should know what type to use, and yes it will be PAG, but you can tell them anyway).

To flush you dump in some chemical, and then blow air through (lots of air, need a compressor) while holding a rag over the other end. Repeat until clean. This will remove all oil & debris.

If you have a decent air compressor, consider getting one of these:

http://www.harborfreight.com/air-vacuum-pump-with-r134a-and-r12-connectors-96677.html

With that you can do everything yourself, except recover the freon. Be nice to the planet, do not vent it. Most small shops will recover the freon for free, if you let them keep the freon. After a good vacuum, you can add the freon & oil (oil first, so the vacuum sucks it in) easily with one of the DIY cans from a parts store.

I always add dye too, makes it easier if you ever have a leak.

 

[bagoon316]

I appreciate the help, but I dont have access to those type of tools and chemicals.

So, I guess my next question...when they evacuate/recover the system, should they also clean it out then? Then I install all my parts, and bring it back to them for oil and refrigerant. Or is the system cleaned out after the new parts are installed?

 

[xci.ed6]

Clean after removing, before installing. the flush chemical is available at most parts stores, carquesthas it gallon jugs.

 

[bagoon316]

Yeah, I talked to a friend of mine works for Mazda/Ford, big Honda guy though, he said they also make it like in a spray paint can, and has a tube on it that has the chemicals in it as well.

I'm looking to borrow an air compressor for this weekend.

-Evacuate
-Remove
-Clean Evap, Condenser, Lines
-Install
-Freon/Refrigerant

Hoping it goes smooth, and I get Icey Cold Air.