I added 3.5 ounces of mineral oil to the compressor, do I need more??

[rothsean]

I drained my compressor and 2.4 ounces came out. I added 3.5 back in.

I put on new hoses, new evaporator, new condenser. Do I need more oil in it than the 3.5 ounces that I just put in it?

[kings1527]

I drained my compressor and 2.4 ounces came out. I added 3.5 back in.

I put on new hoses, new evaporator, new condenser. Do I need more oil in it than the 3.5 ounces that I just put in it?

Did you do a new accumulator, too? From what I found out, these are the generally accepted amounts:

New accumulator: 2 oz
New evaporator or flush: 2 oz
New condenser or flush: 2 oz

The above was in addition to the amount in the compressor. I understand that it's one general system as opposed to two (one in the compressor and one for the rest of the system) but that's what I did and everything's been great.

I drained just over 2 oz from my compressor so I replaced it with just over 3 oz, plus the above amounts. I'm getting 36-38 degrees at the vents with close to 100 degree ambient.

[rothsean]

Did you do a new accumulator, too? From what I found out, these are the generally accepted amounts:

New accumulator: 2 oz
New evaporator or flush: 2 oz
New condenser or flush: 2 oz

The above was in addition to the amount in the compressor. I understand that it's one general system as opposed to two (one in the compressor and one for the rest of the system) but that's what I did and everything's been great.

I drained just over 2 oz from my compressor so I replaced it with just over 3 oz, plus the above amounts. I'm getting 36-38 degrees at the vents with close to 100 degree ambient.




I did new everything, except compressor (it is only a year old).

I don't see any reference to those numbers in the workshop manual. If I go by those numbers above I will have 9.5 ounces in my system. That seems way too high.

[LordFly]

I believe if you check the shop manual, there is a method to check the level using a dip stick. I'm not entirely sure how it's supposed to work since the compressor does not come with a dip stick, but I know there is something in there about it.

[kings1527]

I did new everything, except compressor (it is only a year old).

I don't see any reference to those numbers in the workshop manual. If I go by those numbers above I will have 9.5 ounces in my system. That seems way too high.

The AC system is a standard GM-based Harrison Radiator system, along the same lines as many Corvettes of the same vintage. Cycling clutch orifice tube-based systems of that era are all going to roughly be about the same so when it comes to looking up numbers like this, it's not strictly DeLorean-indiginous. I researched many resources on it, one of them being a manual dealing strictly with CCOT systems and while everyone's a little different, the amounts I listed were the most consistent.

Keep in mind that the oil you drained from the compressor is only part of what's in your system. When changing out oil from the compressor, you add one additional ounce due to residual in the compressor that you won't be able to drain but you'll have residual that gathers elsewhere that's outside of the compressor such as at the base of the condenser, inside the evaporator and also inside the accumulator. Obviously, draining the compressor won't do anything for those other locations.

If you didn't replace or flush the other components in your system, probably just dealing with the compressor would be fine but take into consideration all of the other components you replaced and have NO residual oil in them since they're brand new.

On another note, I'd much rather have too much oil in the system compared to too little. I've been having great performance and no issues with my system since I did this. I want to say I added a total of about 8.5 oz to my system plus 1/4oz of dye, done separately: the oil change out through the compressor and then dumping the other oil straight into the low side when I was ready to bolt the lines up to the compressor.

[David T]

The AC system is a standard GM-based Harrison Radiator system, along the same lines as many Corvettes of the same vintage. Cycling clutch orifice tube-based systems of that era are all going to roughly be about the same so when it comes to looking up numbers like this, it's not strictly DeLorean-indiginous. I researched many resources on it, one of them being a manual dealing strictly with CCOT systems and while everyone's a little different, the amounts I listed were the most consistent.

Keep in mind that the oil you drained from the compressor is only part of what's in your system. When changing out oil from the compressor, you add one additional ounce due to residual in the compressor that you won't be able to drain but you'll have residual that gathers elsewhere that's outside of the compressor such as at the base of the condenser, inside the evaporator and also inside the accumulator. Obviously, draining the compressor won't do anything for those other locations.

If you didn't replace or flush the other components in your system, probably just dealing with the compressor would be fine but take into consideration all of the other components you replaced and have NO residual oil in them since they're brand new.

On another note, I'd much rather have too much oil in the system compared to too little. I've been having great performance and no issues with my system since I did this. I want to say I added a total of about 8.5 oz to my system plus 1/4oz of dye, done separately: the oil change out through the compressor and then dumping the other oil straight into the low side when I was ready to bolt the lines up to the compressor.

The Sanden site has the info on how to make and use a dipstick. I would make sure you have at least that much oil in the compressor but if you drained the whole system and put all new parts in there is no residual oil "out there" so I would add for each component that was replaced and add a little for the long (longer than usual on most other cars) hoses. Better to have more than less. Too much (way too much) will affect capacity but you would have to seriously overfill to get to that point.
David Teitelbaum

[Ron]

Here ya go-
All this is in Resources, See: Chapter 13 here http://dmctalk.org/showthread.php?353-Sanden-SD-AC-Compressor-Service-Manual.
If you can recover your refrigerant, there are procedures on how to determine the exact amount needed to stay in spec listed even with our long hoses.