Basic Steps and all things needed for AC compressor Change

[zedjr10]

Ok i got all my parts for my AC change. I am first wondering what are the basic steps. Let me list what i got so far. This is a retrofitted 134a system.


1. Evacuate ac system. I got a vacuum pump and that dual gauge set for that.
2. Flush System? Since i am replacing everything almost except the evap core. DO i need to flush system?
3. Does it matter what parts i replace first. I take it it doesn't matter if some air gets in system when pipes are open as i can just evacuate that air before i charge system. IS this right.


Here are all the parts and special tools i have so far. I am mostly wondering what order to do things and the oils i need. Am assuming an air compressor is only for flushing the system. Anything else?

1. Denso oe Compressor.
2. Expansion Valve.
3. Dryer/Accumulator.
4. vacuum pump.
5. AC Manifold gauge set.
6. Complete o-ring seal set.
7. Schrader valve set.
8. Condenser - am going to replace it to be on safe side. Denso oe is 53 dollars at rockauto. OEM is 200 dollars.

[9tAkord]

Did the same work done back in 2014. Replaced the compressor, condenser, expansion valve and drier. Flushed all the lines and evaporator. I also used a Denso OE compressor, just take a note of what oil was in it. Mine was ship with ND-6 oil. I had to drain it as much as I could and replaced it with honda pag oil ND-8 part no.38897-PR7-A01AH. Check out this thread http://www.cb7tuner.com/vbb/showthread.php?t=165508

[zedjr10]

Did the same work done back in 2014. Replaced the compressor, condenser, expansion valve and drier. Flushed all the lines and evaporator. I also used a Denso OE compressor, just take a note of what oil was in it. Mine was ship with ND-6 oil. I had to drain it as much as I could and replaced it with honda pag oil ND-8 part no.38897-PR7-A01AH. Check out this thread http://www.cb7tuner.com/vbb/showthread.php?t=165508

What method did you use to flush system or did u pay a shop. I seen a method that uses a vacuum and basically vacuums the flush thru system but everyone else uses a compressor and a flush kit. I take it once system is flushed and evacuated there is only a vacuum in lines and now it is safe to open and start changing parts. Mine has a leak so might be equal pressure as outside air. Is this right?

I read some of that link. That guy is taking everything out. Holy crap. I don't intend on doing this. I'd be there for weeks possibly. It is good so i can my steps down right. I think i will pay a shop to flush.

[Size9zombie]

Flush the lines while everything is apart. You don't want any old oil or residue left in the lines, it will contaminate the new oil and refrigerant you are putting in. Easiest way to flush system is to use a flush kit with a compressor for your air source. Doesn't matter what order you replace the parts in. For best end result make aure you pull a good vaccum (at least -30 inHg) for 30 mins or so before you charge it back up. 9tAkord covered the oil.

[zedjr10]

I am going to have to pay a shop to flush it. I got no air compressor. So i can't take it all apart. Then i assume i can install whatever part in whatever order. I will start with dryer then condenser or expansion valve. DOing the compressor last. Am still a bit confused about this oil stuff. Compressor and condenser take pag 46 oil with 134a and then when i charge for first time i add some other oil? IS this right.

[zedjr10]

Did the same work done back in 2014. Replaced the compressor, condenser, expansion valve and drier. Flushed all the lines and evaporator. I also used a Denso OE compressor, just take a note of what oil was in it. Mine was ship with ND-6 oil. I had to drain it as much as I could and replaced it with honda pag oil ND-8 part no.38897-PR7-A01AH. Check out this thread http://www.cb7tuner.com/vbb/showthread.php?t=165508

How do you know what oil to use?

[F22Chris]

It’s based on the compressor. Same way some engines need 0w20 and others need 15w40. Clearances and such. That, and r12 oils don’t mix with 134.

Don’t use mineral oil. Nd8 is good, you can also use the 46. Some people use ester.

Pull vacuum for as long as you can. 30 minutes is fine, but the longer you vacuum, the better. Dry = good.

Remember don’t fill on the high side.

[zedjr10]

It’s based on the compressor. Same way some engines need 0w20 and others need 15w40. Clearances and such. That, and r12 oils don’t mix with 134.

Don’t use mineral oil. Nd8 is good, you can also use the 46. Some people use ester.

Pull vacuum for as long as you can. 30 minutes is fine, but the longer you vacuum, the better. Dry = good.

Remember don’t fill on the high side.

OK fk it. I bought an air compressor tonight. Shop wanted 250 to flush it. Good reason to buy a cheap air compressor. Now i just need to buy the oil. I guess pag 46 will work. First think is to evacuate system, right. Then when i take things apart i can flush the sections of system while on car. As long as i don't flush in an area where i put a part on. Is this right?

[zedjr10]

How much flush solvent do i need? Less than a quart or more than 3.
Should i get anything else like evaporator cleaner?
So use pag 46 oil for everything like coating o-rings, the compressor oil and condenser oil.

[Size9zombie]

$250!? That's crazy, disassemble everything, then flush all the lines and the evaporator, pag 46 will work just fine. 1 qt of flush should be plenty, it doesn't normally even take that much. Drain both new and old compressor, measure how much comes out of the old 1 so you know how much to put back in it, same with condenser. Yes coat o rings and such woth the pag 46. When you say you are going to evacuate the system, how are you goin to recover the refrigerant that is in it? You shouldn't vent it to atmosphere as it is harmful to the environment and you if you breathe it.

[zedjr10]

$250!? That's crazy, disassemble everything, then flush all the lines and the evaporator, pag 46 will work just fine. 1 qt of flush should be plenty, it doesn't normally even take that much. Drain both new and old compressor, measure how much comes out of the old 1 so you know how much to put back in it, same with condenser. Yes coat o rings and such woth the pag 46. When you say you are going to evacuate the system, how are you goin to recover the refrigerant that is in it? You shouldn't vent it to atmosphere as it is harmful to the environment and you if you breathe it.

Honestly not sure how i am going to capture it. I thought most of the freon would of leaked out by now as it normally does. I will look for a capture can that i can buy or rent out.