AC oil...

[SHOtimer]

So, I have my dash pulled out of the my SHO as i'm doing the BDA. While I was in there I figured I'd do the blower motor, and heater core (since I don't plan on going back in again).

So, all that to say is the AC is disconnected. It worked before, but didn't perform the greatest. While it is all apart I am replacing the condenser, accumulator, and orifice valve.

The HVAC system was on it's back while I changed the blower motor and a lot (I assume most) of the AC oil drained out of the evaporator.

So, at this time the only part of the AC system that has oil in it is the compressor, albeit I don't know how much - how much could be in there?

IIRC, the total system holds 7oz?

How much should I put in the evaporator, condenser, and accumulator? How much should I assume is in the compressor?

Thanks guys, looking forward to a properly functioning HVAC system

Doug

 

[rubydist]

i would drain the compressor too, and then put the (iirc) 4-6 oz of lubricant in there. its better to have a little too much than not enough, but you don't want a lot too much.

 

[Mr Anonymous]

i would drain the compressor too, and then put the (iirc) 4-6 oz of lubricant in there. its better to have a little too much than not enough, but you don't want a lot too much.

This, plus drain the condenser if you're not replacing it as well. It's really the only way to ensure you have the exact oil charge in the system.

There should be 1oz or less standing oil in the evaporator, drier, and condenser. The problem is that most DIY refrigerant contains oil so every time the system gets topped-off you end up having more oil and less refrigerant which also impacts how well the A/C cools.

Normally, while the oil is circulated through the system along with the refrigerant, a minimal amount will settle in the low points of the drier, evaporator, and condenser; but once there is more oil than the refrigerant can transport, you start getting larger amounts of oil building up.

 

[SHOtimer]

This, plus drain the condenser if you're not replacing it as well.

The problem is that most DIY refrigerant contains oil so every time the system gets topped-off you end up having more oil and less refrigerant which also impacts how well the A/C cools.

Normally, while the oil is circulated through the system along with the refrigerant, a minimal amount will settle in the low points of the drier, evaporator, and condenser; but once there is more oil than the refrigerant can transport, you start getting larger amounts of oil building up.

The condenser is getting replaced.

So, if I drained more than 1oz out of the evaporator by itself, does that mean my system had an oil overcharge?

Would that have hindered performance?

So, If I drain the compressor - should I still put 4-6oz of new oil in the system?

It will be getting professionally vacuumed and recharged with pure R-134a.

Doug

 

[Mr Anonymous]

The condenser is getting replaced.

So, if I drained more than 1oz out of the evaporator by itself, does that mean my system had an oil overcharge?

Would that have hindered performance?

So, If I drain the compressor - should I still put 4-6oz of new oil in the system?

It will be getting professionally vacuumed and recharged with pure R-134a.

Doug

Yes, Yes, and according to the shop manual the proper oil charge is 8oz.

 

[SHOtimer]

Awesome, thanks.

Doug

 

[SHOtimer]

...went to buy PAG oil today. They have PAG 46, 100, and 150.

They all seem to be compatible with R-134a, and I can't seem to tell a difference. Any insight, which one do I need, which one is best?

Thanks!

Doug

 

[32MTX]

pag 46 or denso 8 oil

 

[SHOtimer]

pag 46 or denso 8 oil

Ok cool, i'll return the other two and use the 46.

What are the numbers, is it the viscosity of the oil?

Doug

 

[Zap]

The numbers do refer to the viscosity:

PAG (ISO) 46 is thin
PAG (ISO) 100 is middle of the road
PAG (ISO) 150 is thick