Total ac system oil amount

[regularnothing]

My 99 lx 470 had an ac compressor failure because the ac system was in bad shape. I’m going to be flushing the lines and replacing basically everything. The compressor, front and rear evaporator, front and rear expansion valves, condenser and the ac lines that have the mufflers on them. I’ll also be using Nylog on all the connections and o rings.

Since I’m basically starting with a clean system with nothing in it. How much PAG oil do I need to put in it? Ive tried looking but I keep seeing mixed answers on the exact amount for each part.

Also to add the PAG oil, I just pour it straight into the evaporator/condenser/compressor before installing it back? Or is there a special way of adding it.

 

[FearlessWaterfall]

2oz in the the compressor’s high pressure side. But confirm with your year. Mines is an 06. I just replaced the compressor over the weekend

 

[regularnothing]

2oz in the the compressor’s high pressure side. But confirm with your year. Mines is an 06. I just replaced the compressor over the weekend

2oz for the whole system? Or just the compressor. What about the front and rear evaporator and the ac condenser:

 

[awesomeissquid]

From my research the video is not exactly correct. Someone else had called Denso and confirmed the compressor comes with around 6oz of PAG oil. I can confirm this is around what I drained out of one this past weekend.

With rear AC, the total system oil capacity is somewhere around 8.5oz to 10oz. Oil capacities per component for a dry system (flushed with new components) is as follows to get to 9oz:

• Compressor - 4oz (120mL)
• Rear Evaporator - 1oz (30mL)
• Front Evaporator - 40cc = 1.4oz (40mL)
• Dryer - 1/2oz (15mL)
• Condenser - 2oz (60mL)

 

[2001LC]

I've heard, anywhere from 9oz to 11oz.

I R&R, a leaky AC compressor this week. With new Denso.
Old AC compressor had 1/4 oz oil remaining. Assume most its oil, leaked out.
Denso came with ~7oz. I drained added back 4oz.
R&R drier, soaked it with ~3/4oz.
Added 1-1/4 oz to low side.
Vacuumed & Charged w/3 cans R134a
A/C blew 45F, after sundown OAT 79F.

To much oil: System doesn't cool as well as should.
To little oil: Compressor may burn up.

 

[LazarusTaxa]

From my research the video is not exactly correct. Someone else had called Denso and confirmed the compressor comes with around 6oz of PAG oil. I can confirm this is around what I drained out of one this past weekend.

With rear AC, the total system oil capacity is somewhere around 8.5oz to 10oz. Oil capacities per component for a dry system (flushed with new components) is as follows to get to 9oz:

• Compressor - 4oz (120mL)
• Rear Evaporator - 1oz (30mL)
• Front Evaporator - 40cc = 1.4oz (40mL)
• Dryer - 1/2oz (15mL)
• Condenser - 2oz (60mL)

I also just replaced all of the AC components in my 100 and am about to charge it.. Do I need to drain the compressor and add those specific amounts to each component, or can I leave it all in the compressor and let it circulate from there (while adding some more to one of the lines to get to the 8.5-10 oz)?

 

[awesomeissquid]

Compressor should be drained of the oil it comes with and replaced with the correct amount of fresh PAG46 (4oz per the above list). Any other components that are replaced should have the correct amounts of fresh oil added to them directly.

I believe this is recommended for two reasons:
1. We want to ensure the compressor has fresh/clean oil in the correct volume for our system.
2. We want to avoid running the compressor dry. If the compressor has the full system volume at start, the refrigerant will circulate it around eventually, but until it does, the refrigerant returning to the compressor would be dry. I believe this could damage the compressor internally.

If you are planning to liquid fill the first can into the high side with the system at vacuum, be sure to spin the compressor by hand 10-15 times after charging before starting the engine. This further helps circulate the oil a bit.

 

[LazarusTaxa]

Makes sense.. I suppose after replacing the rear hardlines with hose, it's not much more work to disconnect and add a little oil.

- that job sucked and was only made 1000x worse by having fluid filmed my truck in the fall.