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A/C On My 80 D150 318 4 SP


Active Member
May 14, 2016
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Speedway, IN
Need some input on what it takes to convert my a/c system over to 134. I have taken everything off the truck, but have it. Someone told me it was not a big deal to make the change over to 134 but others seem to disagree.

What the real scoop guys? I'm not on here a lot, so leave me some comments please, and I will check back in down the road.

Thanks, Larry

65 sporty

Well-Known Member
Aug 8, 2015
Reaction score
Kingston, Mi
Some guy's go all out and change everything but you don't need to. If the system has been open you need to change the receiver/dryer, I would also change the expansion valve. If you have access to some flush and a flush gun it wouldn't hurt to flush the condenser and evaporator. Add the recommended amount of Pag oil. I don't use Ester oil too many problems with it. Change the fittings, vacuum the system and recharge it. When adding the oil put some in each component.

Some say to only add a 80 percent charge but I have used a 100 percent charge with no problems. When we first started doing the retrofits they were saying only 80 percent but later classes I had said up to 100 percent. You have to watch the pressures and the sight glass. I did a 88 B250 last year this way and it works great, pressures are really good with 100 percent charge and cools good. Good luck