A/C conversion in a car with AutoTemp.

[celticwarlock]

Hello, all. My '69 NY originally came with an AutoTemp system which, of course, does not work as it should. I have no interest in repairing it, and I cannot convert the car to a conventional A/C system just yet (I have the parts, but not the time....lots of other large projects must come first). I am converting it to 134a. I have installed a manual flow valve under the hood to stop the flow of coolant into the heater core, which I hope will enable me to get cold air at the vents once modifications have been made. My system has enough R-12 in it to kick the compressor on, but not enough to blow cold air (one of the seals has a very slow leak), so it seems likely that the compressor works. It is my understanding that I must replace the receiver/dryer, all the o-rings (to the green ones), get as much mineral oil out of the system as I can, drain the compressor and refill it with ester oil, change the service ports, pull a vacuum on the system for an extended period, and refill it with 134a, but I have the following questions: How much oil is the compressor going to need? Does anyone have a link to the part of the FSM that gives instructions on how to fabricate a dipstick for the compressor? When the system is filled, will the compressor clutch cycle on and off, or is this system not designed that way? Also.....unless I find it necessary to replace them, I am using the lines I have on the car. Other systems I have converted successfully did not require this, but again, if they are marginal upon close inspection, they will be chucked.

 

[Big_John]

It should be the same as a 70 FSM.
MyMopar - Mopar Forums & Information - Service Manuals

 

[celticwarlock]

Does anybody know what sort of o-rings I will need? Should I just get a large assortment, or is there a specific kit? Finally....there is a very slow leak at the joint where one of the lines bolts to the compressor (looking at the compressor from the front, it is at the top of the compressor face; the line has a flange at the end and a bolt securing it to the compressor). Is this sealed with an o-ring, or (as I suspect) some sort of special gasket?

 

[1978 NYB]

Just get a large assortment of green o-rings. You'll also need to get the metal gaskets that go on to both sides of the compressor hoses to the compressor. NAPA and AZ have them.






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[75LandYacht]

Just get a large assortment of green o-rings. You'll also need to get the metal gaskets that go on to both sides of the compressor hoses to the compressor. NAPA and AZ have them.

Bob.. Funny I came upon this thread, I just removed the 2 hose yesterday with intent on sending them out to be rebuilt / reconditioned since I'm redoing my under hood A/C system. I remember you responding to my same question on an earlier thread but cant't find it.. So! where do you recommend I send them out for servicing?

Thanks in advance for your time.




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[75LandYacht]

Bob.. Here is a pic of my A/C hose I Took off that I'm requesting help with. As if you don't know what they look like. Lol

 

[celticwarlock]

Is there a part number for it? When I do a search on those sites, a bunch of non-vehicle specific items pop up. I would like to have the correct one on hand when I open up the system. There are oval ones, elliptical ones with multiple holes, round ones of at least 2 sizes, and a huge assortment of odd looking stuff. Which one do I need?

 

[celticwarlock]

Just get a large assortment of green o-rings. You'll also need to get the metal gaskets that go on to both sides of the compressor hoses to the compressor. NAPA and AZ have them.






p

When I took the hose off of the front of the compressor, I found an o-ring on the flange, not a metal gasket. There is a slight recessed area machined into the flange where the o-ring sits, so it's clear it belongs there. Finding one comparably sized proved surprisingly difficult for some reason. I got my hands on a few good sized assortments from a few different places and could not locate one that fit precisely. In the end, I fabricated a gasket for it. I have since converted the system and it seems to work well, though the force of the blower motor is somewhat less than I'd like. I replaced every o-ring I could get to, thoroughly flushed and cleaned out the condenser and compressor, refilled the compressor with ester oil, changed the dryer and all the valves, vacuumed it down for an extended period (the needle held FIRM at 26 in./Hg), then filled it up to 70% of the R12 capacity. Vent temp is about 40 degrees at idle, fully warmed up, with an ambient temp. of about 82 degrees. So far, so good.

 

[commando1]

40°. Excellent. You done good!