OK if converted to R134 then the chart in the shop manual is wrong and you need to use R134A pressures. The system won’t cool as well with R134 due to less efficiency so it needs to be spot on with the substitute refrigerant.
Also of course the compressor lubricant is different and the expansion valve would need to be swapped for either a valve or orifice that is compatible with R134A. Finally the system would need to be flushed and a new drier installed to effect the change successfully.
Haven’t experienced or used to rotolock or service type valves to any extent in the past so I’m learning here. Both valves were in the fully outward position closing everything off. One on the high pressure side looks newer than the one on the low pressure side. I was able to wrestle and eventually turn the high pressure one in and open the valve. A little pressure and small amount of fluid came out. The other one on the low pressure side is a different story and I can’t get it to budge. So any readings on the gauges or vacuuming the system were of no use because everything was closed off. Need to get the service valve on the low pressure side to open so I can truly troubleshoot and resolve this issue. Not real confident I can as the valve end looks pretty butchered or stripped and is not a standard socket or wrench size. Think it might have been 5/16" or 7mm at some point, but that has been machined in an amateur way over the years.
The end of the service valve is originally square. A previous owner probably used an adjustable wrench and rounded it off.
The service valves are really cheap. Best to replace any that show any signs of damage. Freon is too expensive to install in a system that is anything but tip top condition.
I totally agree! We can easily tell XR7–428 what he should spend his money on.
I have read, but I have not researched it so I don’t know whether it is really true, that because the only demand for R12 anymore is to service very old refrigeration systems, and a lot is still being recovered as old systems are taken out of service, that there is a glut of R12 on the market. A licensed installer should be able to get recycled R12 cheap.
Is there anyone who has first hand knowledge on this?
I remember when Dad pulled our 64 Comet into a filling station in LA to get the quickie $4.95 AC charge special. The kid didn’t know to set the valves half open, and completely closed off the compressor from the system. I remember watching the belt slipping on the compressor and the kid yelling “stand back, it’s gonna blow”. It didn’t, and once he finally got it charged and belt replaced, it worked for years afterwards. Hopefully no damage was done here either.
Absolutely. Trying to find ones that look correct. Any leads for a good source? While I have several cans of R12 on hand, the compressor has been R134a converted at some point by classic auto air so the Freon cost isn’t too bad. Maybe one of the very few positive things going for this basket case.
I would try my nearest auto part store first. They are all over eBay and Amazon. Old Air Products in Ft. Worth. WCCC. Any vendor of old Ford or Mercury or Lincoln reproduction parts.
WCCC is consistently out of stock on most things I’m looking for. Local parts stores give me a blank stare. Online search shows a few different options. Combination of two #8 flare hoses or one that is a combo of a #10 and the other that is a #8. Not sure what compressor it is but I’m guessing it’s a back-seat Rotolock York R210L. Would the valves come with everything needed or would I need additional parts like O-rings? If anyone could provide a link to what I’m looking for it would be greatly appreciated.
Thanks, but I need this one that shows out of stock.
Looks like NPD has both #8 and #10 valves in stock.
Great thanks
Once I figured out the service valves, I vac’d the system and let it sit for 2 days. No difference in gauge readings. As Royce said it would take a can of refrigerant without turning on the car and engaging the compressor. It did with no issues. Today I tried to completely charge it, but it doesn’t seem to want to take any more refrigerant and I’m not sure why. Ambient temp was 65 with 100% humidity. It took the first can with engine off, but only took about half of the second can with engine on and compressor engaged. Pressures were in the middle of the gauge for the high side 150-200 sitting in between and on the low side they would default to just under 20 when I shut the valve on the manifold gauge, but when I opened up the gauge and the can of refrigerant it went up to between 60 and 80, but again it didn’t seem to accept any refrigerant even-though the can and low pressure line kept getting cold and the car was pouring condensation on the ground. There were also bubbles in the sight glass so I’m assuming it doesn’t have a full charge. This is r134a refrigerant. Pressures seem to be in the normal range but the temp of the output from the interior vents is cool, doesn’t seem cool enough.
Any ideas?
At 100% humidity, you won’t get much temp drop at all. All the energy is spent pulling out the humidity, and it sounds like yours was doing so. Not right to see bubbles in the sight glass though. I always used to put the charge can upright in a pan of warm water and the system would then take a bit more charge. Engine needs to on fast idle cam idling around 1500 rpm too.
It was at idle not fast idle. Between 6 and 700 RPMs. I sat the can on the battery inside the engine compartment where it was warm.
Probably needs more RPM. I would expect low side pressure near zero when it is full and much higher on the high side. I only use R12 so no idea what R134 does.
Yup, more RPM, and a pan of warm water will transfer heat into that can a whole lot better than a warm battery. Higher ambient temp and lower humidity day might help too. Like Royce though, my experience is limited to R12.
Anyone on here with R134a conversion of an original system experience? Metrics, temps, pressures?
R12 was the best, but is extremely expensive, essentially unavailable, and quickly becoming a thing of the past.
I understand that R134a is actually more efficient in a system designed for it, but of course our Cougars weren’t. Can certainly understand making the switch though.