A/C Compressor

[texasmike]

I located a beautiful NOS Harrison model no. 1131622 R4 compressor to replace the fifth automotive store unit. It is set up for R-12 so what needs to be done to prepare it for 143a refrigerant and will the original seals be damaged or adversely affected?
Thanks.

 

[CalSgt]

To the best of my knowledge just clean the compressor oil out of it, replace with PAG oil, put the system under vacuum and charge with refrigerant.

ETA: If no oil is in the compressor PAG is safe to use, however some say the old mineral oils react to the PAG oil and recommend Ester oil when filling a system that previously used mineral oil. I've also heard the PAG oil is fine to use after mineral oil so maybe they've changed it

 

[Sad Sack]

You should also consider a new accumulator, orifice tube filter and a new condenser when converting to R134. I converted mine with a new compressor (with PAG150 oil), filter and accumulator but I didn't replace the condenser and seems to work just fine in my case. New compressors usually require the filter and accumulator to be installed/ purchased at same time for the warranty to be effective.

 

[edgephoto]

If your compressors are failing because they are disintegrating. You need to get all that debris out of the system or it will destroy your new compressor.

Simplest way is to replace everything but it is the most expensive and time consuming. There are flush products that can be used. Pro shops have filter setups that do a thorough flush of the system.

 

[Finkaire]

Drain the oil change the accumulator, and the orifice tube. The orifice tube often gets stuck, you might consider leaving it in there than to destroy it and still being unable to remove it. MOST important, use an ESTER oil. PAG oil is a corrosive and may take out the evaporator! My 2 cents LOL