Recent content by MaxPF

Hmm, curious. I'm guessing it isn't an NOS unit? Just out of curiosity, are the drier fittings o-ring or flare? What were the pressures before and after you removed refrigerant? Good to hear! Yeah, voltage drops caused by multiple switches and small wiring are a common cause of clutch...

Jim, not sure if you missed my post on 21 May: with the engine running at 1500RPM, does the sight glass clear up? Or at least show minimal bubbles?

Interesting. Again, 85°F isn't hot, but those pressures seem low. Especially he discharge pressure. The system sounds undercharged to me. When running at around 1500RPM, does the sight glass ever clear up?

Is the condenser tube and fin, or serpentine?

If it's a 1976 and has a V-configuration compressor, then it should be an RV2. The V2 was replaced by the RV2 in the early 60's, IIRC.

You're using the original condenser? Is it serpentine, or tube and fin? What are the pressures? I'm just amazed, because I haven't seen many R-134a retros using the stock tube and fin condensers that worked that well and didn't have sky-high discharge pressure.

Make sure it is an RV2 compressor. IIRC, some Chrysler vehicles had dealer-installed AC systems that used a different (York?) compressor. It's easy to tell if its the right one: if it's a "V" configuration, it's an RV2 ;-)

That is odd. With the EPR, a low pressure cutout won't protect against evaporator freeze. It will shut down the system if you lose most or all of the charge, but that's all. I will have to go back and watch the relevant Chrysler Master Tech videos. They talk about which vehicles used the EPR...

I thought all systems had an evap temp switch, including those using an EPR. EPR's have a setpoint of around 24psi at low load, give or take a psi or two. At that pressure, the saturated temp of R-12 is well below freezing. The reason the evaporator usually doesn't freeze is the temperature drop...

Ahh. OK. That means the Duster was originally a cycling clutch system, not an EPR system. I don't recall off the top of my head which models used which systems, but I do recall that the higher-end and/or large sedans used the EPR while more compact and/or mid-range vehicles used clutch cycling...

The pressure drop probably isn't too bad. I'm surprised that you don't have a Schrader port on the suction manifold where it bolts to the compressor body? You must be using a line set from a non-EPR vehicle? I'd get the best measurements that you can. A slightly inaccurate measurement is better...

I would highly recommend running the OE RV2 compressor. The typically retrofitted Sanden not only looks out of place, but it doesn't have the refrigerating capacity of the RV2. Granted, NJ isn't the hottest place in the US, but I still wouldn't want to downgrade the AC from OE.

Not surprising. The original hoses were made of nitrile. It was determined back in the early 90's, when systems were being studied to determine what steps would be necessary to retrofit an R-12 system to R-134a, that nitrile hoses which had seen at least a season of use would have absorbed...

Your mention about holding vacuum for 24hrs is notable. I have long been a proponent of keeping R-12 in any system that was originally R-12, especially of you want to use the original condenser. Many balk about the cost, but in the scheme of things the cost of a full charge of R-12 isn't that...

Unless the superheat is way off, I would leave the valve alone. They are adjusted from the factory for an appropriate amount of superheat, and the difference in superheat with R-134a will only be a degree or two at most. Not enough to worry about. For the enlightenment of those who wonder about...