79 ac oil charge

[1yy07]

book calls for 6oz dry system is this right? if so how much goes where? new compressor new condenser new filter/dryer flushed evaporator w hecat flush going to use r12 w napa wax free mineral oil 500 viscosity:confused help? please and thank you

 

[Bob Heine]

I replaced everything in the A/C system on my '72 as well as my '87. Your '79 has the R-4 compressor so it's probably closer to my '87.

I'm no expert so hopefully someone else who is will chime in. According to the Service Manuals, here are the amounts of oil needed for each component when they are replaced:

• R-4 Compressor: 6 oz 525 refrigerant oil. Be careful here because most new and rebuilt compressors come with oil in them. Manual says to drain oil, measure and replace with same amount of new oil. I just checked to see if it had oil and saw quite a bit so I just installed it.
• Evaporator: 3 fl. oz.
• Condenser: 1 fl. oz
• Accumulator: 2 fl. oz. Like the compressor, manual says to drain the old one, measure the amount of oil, add that amount plus 2 oz more (amount absorbed by the dryer media). I just added 2 oz. to mine.

From these instructions you would be adding 12 ounces to a dry system. That sounds like too much oil to me but I ended up adding the recommended amounts to the components. Shop I took it to for evacuating and later charging the system said I only needed about 8 oz total. System is working fine so maybe a couple of extra ounces of oil isn't a problem.

 

[1yy07]

79 oil charge

thanks bob