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Discussion Starter #1
It is already 85+ degrees here, so A/C use it right around the corner. If if worked I would already be using it after car sits in the sun for a few hours.

I see oily hoses on my 97 Mark VIII, it is cycling frequently, and it doesn't cool (it did when I bought it, a few months ago, but I think like the rest of the vehicle the seller was adding freon right before I would go look at it).

My 89 Cougar has a new compressor but is still R12 configured and needs a charge. The hoses are already barrier hoses.

My 97 Cougar the condenser needs replaced as the front end is toast from accident, it has recent hoses (one year only bolt on to condenser)

So I got a set of gauges, a vacuum pump (2.5 cfm stand alone unit), conversion kit for the 89 Cougar to R134, oring kits for 89 Cougar and 97 Mark VIII, adapter for the cans of R134. I still need to get a accumulator/drier for the 89 Cougar.

So...I haven't done AC work in awhile. I plan on replacing all the orings on the 97 Mark VIII, drawing a vacuum for 30 minutes or so, make sure it doesn't leak/lose that vacuum for an hour or so, then charging it.

The 89 I will replace the accumulator/drier (has been a few years with no freon in the system), the orings, convert the high and low ports to R134, vacuum for longer than 30 minutes, then charge.

Any pointers? I assume when I put it on the vacuum pump that 30 minutes is long enough to draw it down to close to 30, and vaporize any liquids, but not do anything like damage seals? Do you have the low and high sides open when on the vacuum pump?

I am still looking for the specs on how much freon each one takes, how to deal with knowing how much oil I need to put in the 97 Mark VIII, how to get rid of the r12 oil and put in the oil for r134, all that.
 

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Draw vacuum for 30 minutes on both high and low, then shut off the pump and make sure it holds vacuum for 30 more minutes. You can hold if for longer if you want, it won't hurt anything. 29 inHg is only ~16PSI. The o-rings see 20 times that when it gets hot out.

IIRC when dry the system takes 6 oz PAG-46. 34 oz. is the max charge of R134a. You would need to flush the old lines and heat exchangers on the R-12 system to get the HFC oil out. I also recommend you use Nylog Blue on the o-rings instead of oil if you can find it. Also don't forget a new orifice tube in the 89.
 

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Discussion Starter #3
97 Mark VIII, this is the only place I see fluorescing dye. I power washed it but this joint was very oily, and I can still see remnants of the dye on this connection on the discharge hose:



It doesn't look OEM, it looks aftermarket and has been replaced, you can see the muffler (right?) below with what appears to be non Motorcraft pns.


I am not sure how to take a picture to show the florescence, you can see it in the end of the crimp and right at the spring lock:


These white things, they are in the OEM spring locks, and seeing them means that the spring lock has been disassembled, right?


I still haven't had a chance to put the gauges on it to check to see if it needs a charge or is something along the lines of the low pressure switch or the compressor is dying. I see no dye on the hoses/back of the compressor or around the clutch.
 

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The white plastic retainers are installed in the spring locks to keep the springs from falling out before they're assembled. When they're assembled the white clips pop out. If anything, seeing them is more an indication that it wasn't disassembled than it was. But it really means nothing.
 

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This is the 97 Mark VIII on the gauges, I take it that the low pressure switch is kicking in, causing the clutch to disengage? 65 degrees ambient temp.


http://youtu.be/mwIQKUkXMIo
 

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Hard to see the pressures, but yes - that looks normal. It should kick in if the pressure gets above 40ish PSI, then if it drops below about 20-25 it should turn off.

I usually refer to this chart to verify the charge based on the system's pressures. http://www.ackits.com/aacf/ptchart.cfm

Based on that chart your low side would settle in about 15 PSI which is well below the cutoff for the cycling switch.
 
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