what type of PAG oil should be used in a factory 73-79 ford truck with air conditioning i came across all different types like iso 46,iso 100 and so on. which type should i use.

 

I used PAG 100 in my '89 F150 and used PAG 150 in the wifes S10 Blazer and things work just fine.

 

pag oil should only be used for systems that were originally 134a. ester oil is the only oil to use in r12 to 134 conversions. if u look at the conversion kits they sell they all include a bottle of ester oil. pag shouldnt ever be used in a 134 conversion.

 

yes i found that out right after posting this thread. thank you

 

390 gashog..You got a factory original r-12 system? then its not about conversion to r-134a. R-12 used mineral oils , different seal material, dryer materials . By the way, tomorrows new compresser in my 91 will by using the ford recomended and manufactor required pag 46.....good luck...

 

that was my bad. i assumed it was a 134 conversion because r12 is very expensive anymore and almost nobody uses it . you can still get r12 oil charges(mineral oil) from a place in indiana called national automotive lines.

 

uhhhhh? what did i miss i never said anyhting about using r12 yes this is a r134a conversion i will be using synthetic ester iso 100 in the system .the new driers made now are made for both r12 and r134a.

 

390gashog....as i understand the oilissue, ester is for compatibility with trace amounts of leaft over mineral oil.I call it the quickie as the time to completly clean the system, change the accumulators,chage the orfice, etc. The weight of the oil...ford used the 46,100 up for gm. I haven't found any compresser that will be warrented with ester, but any oil grade is better than low or empty system. is this a good system or just get it going kind of thing?