Howdy all. Is there a way to remove the AC evap core on a 71 Deville
without removing the passenger side hood hinge and the whole heat/ac box?
I see that the box is split around the evap core but the factory
service manual still says to do all of the above to get the core out.
Thanks !
Mike Harris
Mike,
It depends on what your end goal is. If you are replacing the evaporator, following the FSM has proved (at least to me) to be the best way to go. I know a while back someone posted a "short cut", but the advantage in following the FSM is in part the fact that you have access to all the dampers and seals, and can correct any discrepancies you find.
Greg Surfas
Plus, as the saying goes "If all else fails, follow the instructions"
Bruce. >:D
I guess what I needed was a dose of reality. Following the book it shall be. ;D
I'm basically going through the whole AC system. Removing the expansion valve
from the core was nothing short of very challenging. Those two were basically
welded together over time. Using a couple of flare nut (line) wrenches basically
resulted in slightly bending the end of the core pipe that connects to the valve.
(very slightly)
So I had anticipated a crack somewhere and a subsequent core replacement.
However I was able to spin off the top of the expansion valve and then use an impact and a line wrench
to remove the bottom part of the valve from the core fitting. (after market expansion valves are not built like this clearly. They are one piece.)
So for now I plan to pressure test the core to see if it's still good. (fingers crossed)
If it's bad I'll remove the hood hinge and follow the book.
Regardless of the outcome my plans are to replace the expansion valve, POA (going with an modified cycling clutch type), drier, existing condenser - cleaned and pressured tested, rebuilt AC hoses and remanufactured compressor.
It will be converted to R134.
When my '72 was converted to R134a, the parts that I know were replaced was the Compressor, and the Drier. This was done before I got access to the car, and have never had a problem with it.
I am pretty sure that the Compressor was replaced because of the unknown length of time the system had been not used. Plus, it was probably easier to replace it than try to clean it out of all the R12 oil.
Bruce. >:D
Nitrogen gas is the pressure test gas of choice. Not certain as to how many psi's meets the mark.
Well I'm doing a bunch of head scratching right now trying to decide which route to go.
Glad I decided to consult you guys.
The A6 compressor I recently bought cam pre-loaded with 3 oz of PAG 150 oil. So if I use R12
I'll need to drain and flush that. Also I'll need to find a source for a POA. That is proving
a bit more difficult than anticipated. More to come.
Mike
Drain the PAG thoroughly but do not flush the A-6. Add 5oz of mineral oil and with the compressor in its operating position (sump down) rotate the shaft a couple dozen times to get the oil pump primed and oil circulating.
How do you know the POA is bad?
Greg surfas
Hey Greg. I'm all done now with the rebuild. I seriously considered sticking with R12 but
the ease of obtaining R134 was the primary factor in my decision to convert it.
The POA would ice up after driving the car for a while. It took 1/2 hour sometimes. Sometimes an hour. Also the compressor blew out it's seals. I really cannot say 100% that the POA was at fault.
So I simply chose to go through the entire system.
I'm done now and it seems to be working well. Now of course we've not seen 90+ temps here in
Alabama yet so it remains to be seen how well the system will operate in properly hot temps.
I keep all of my old parts, including this POA, which apparently can be rebuilt. I'll hold onto it and see how things go. (it is kind of nasty down inside)
I installed a new expansion valve and drier along with a reman compressor. (Murray from Oreilly)
I thoroughly flushed the evap core and condenser and all lines. Rebuilt the lines with new rubber and ferrules from Cold Hose. I replaced the POA with a "fake" kit from Old Air that includes a temp
switch to cycle the compressor.
Lastly I added a pair of small 6 inch pusher fans on the front of the condenser. (one on either
lower corner) They are controlled with a relay which uses the A/C on signal so they run all the time if the A/C is on.
The $50,000 question is, what type of compressor did you use? An A-6 designed for R-12 or a 'fake' A-6 designed to use R134-a? The cycling of the compressor from the pressure switch will cut it's life very short. Old Air also sells an aluminum 'fake' A-6, but you have to modify the brackety on the front cradle bracket and use spacers between the rear bracket and the unit itself.
The bracket modifications will get you the compressor sitting properly and the proper drive belt alignment. I've been running mine for 10 years with 0 issues and have never had to have it serviced since it was installed. I also used a parallel flow condenser. That helps cut the need for additional fans. Plus I have a direct drive cooling fan. Here in Florida, I want all the air flow I can get across the condenser.
I did look at those over-price "fake" A6 compressors on Old Air. I didn't like the looks of them. I used a reman A6 from O'Reilly (their Murray brand). It fit perfectly and seemed to be a very nice unit. It was sealed up nicely and pressurized a little when I removed the plugs. It runs quietly. It came loaded with 3 OZ of PAG 150, so I'm guessing they assume most folks would run R134 in it.