A/C system...

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Jul 31, 2017 | 08:24 PM

clajac

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Heel & Toe

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A/C system...

When adding oil to an ac compressor what would be the normal amount of ounces to add and what type would you suggest. this is for a c3 system.

thks

Jul 31, 2017 | 10:17 PM

7T1vette

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From: Crossville TN

Do you know what kind of refrigerant was in the A/C system previously? The C3 cars were built using R-12 refrigerant and mineral oil (#525 compressor oil; 11 ounces in the 1971 system). But, any stock system can be converted to use R134a refrigerant, which must use PAG oil, instead. The two different oils do not mix and the system must be cleaned to do the switchover. So, you need to know what was in it, so that you can re-fill with the correct oil.

Last edited by 7T1vette; Jul 31, 2017 at 10:18 PM.

Jul 31, 2017 | 11:00 PM

REELAV8R

Le Mans Master

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From: Hermosa

Ester oil is compatible ( can be carried by) both freon types.
What year we talking about?
Is the system empty of oil or are you adding due some loss?

Aug 1, 2017 | 08:00 AM

clajac

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Heel & Toe

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I have completely removed the entire system and thoroughly cleaned both the eva & cond and installing a new accumulator and rebuilt compressor.

Aug 1, 2017 | 08:38 AM

marshal135

Safety Car

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From: Madeira Beach, FL

2024 C8 of the Year Finalist - Unmodified

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My 68 calls for 8 oz of ester oil. I'm staying R-12.
3.25 lbs of Freon.
Marshal

Aug 1, 2017 | 11:14 AM

REELAV8R

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From: Hermosa

Since it's empty you can add whichever oil is appropriate to the refrigerant being used.
PAG for 134a
Mineral for R-12
Ester for either one.
If there is any doubt about the system being completely clean of mineral oil for a R12 to 134a switch then use the ester oil to prevent oil incompatibility problems.

Can't answer the quantity question without knowing the compressor type.

A6; long skinny or R4; short fat.

Last edited by REELAV8R; Aug 1, 2017 at 11:16 AM.

Aug 1, 2017 | 05:58 PM

REELAV8R

Le Mans Master

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From: Hermosa

Had a chance to look it up this afternoon.
According to my 77 service manual;

R4=6oz of oil

A6=10.5 oz of oil

If using PAG it looks like the recommend wt is usually PAG150.