A/C refill question

Dale Puumala

Registered User
Where is the low side port on the A/C for refilling? This is on an '89 SC.

I'm trying to do the convert from R12 to R134 and I don't see the low-side port anywhere.

Thanks,
Dale
 
haha this one i can help with :)
i just posted that yesterday..
its next to the ARC cover on the passenger side shock tower. mine was hidden underneath the fuel lines. makes it easier to get at if you take the ARC cover off..
 
About 6 inches behind the ARC actuator ( near firewall) on the pass side, you'll see the pressure switch with a 3 wire connector. Unscrew it and you'll find the LP fitting. ( They done hid it, hehe).
 
Damn, I must be an idiot or blind. :D

I sure don't see it under there. I unplugged the 3-wire connector labeled "A" in the picture. Is it in this picture or am I off?

Thanks,
Dale

<img src="http://members.tccoa.com/dalepuumala/images/ac.jpg">
 
Dale,

Item "A" is your compressor cycling cutoff switch. The low port is on the suction line which feeds out of the front of the accumulator. The accumulator is the black canister where switch "A" is mounted to.

The black steel tube which goes from the accumulator back to the firewall is the evaporator outlet. The line you're looking for exits from the front. The valve should be about 8 inches along that line towards the compressor.
Its probably buried under that wire bundle and the 2 fuel lines.
 
OK, I found it. When you unscrew that pressure switch, that pressure switch is actually screwed in to the low pressure valve. Which brings up a question.

When you're filling it, you're supposed to be running the A/C system while it's filling. How are you supposed to do that if you have to have the pressure switch unplugged to fill it, which in turn disables the A/C system since it reads no pressure.

Dale
 
its not there.. atleast not on mine.. i looked and looked and looked there too. follow the AC lines towards the front of the car a little until they pass between the black shock ARC cover, and its right there on mine.. move the fuel lines around, as mine were covering it so i couldnt see it..
heres a pic of where it is.. its the light blue cap in teh pic

lowside.jpg
 
Guys,

I had an interesting conversation with a Ford mechanic yesterday morning while he recharged my '90 SC with R134a. The car had already been converted by the previous owner.

The mechanic told me that there is no major conversion on the '90 SC's. He said the only thing that Ford does is to replace the O-rings with the newer, green O-rings. Then he said they add a specific amount of that "PAG" oil, which is apparently an ester oil made to be compatible with the newer style refridgerant. Finally, they screw on the adapters for the fittings on the A/C lines, and charge the system up.

I asked specifically about some of the other things I had heard about, like orifice tubes, different compressors and dryers, and he said that none of that should have needed to be changed. Is this guy for real, or have there been a lot of Super Coupe owners getting sharked for A/C conversions???

On my car, the O-rings were in fact all the green type, and the adapters were in place to allow the R134a to be pumped in. Otherwise, it looks like nothing has been changed from stock.

Who's telling the truth here???

Best regards,

Sean
 
Grifter,

I definitely don't have the valve where yours is. The only place I could find a valve was by unscrewing the pressure switch labeled "A" in my pic. And it was actually screwed in to the valve. But, of course you can't run the A/C when you have that unscrewed.

Dale
 
Not just Sc's but most cars dont require any new equipment to take R-134a other than changing the ester oil and refrigerant. You may also notice that most of Ford's newer cars use a very similar setup with the same compressor. My brother's 98 Mustang is almost identical to my 91 NA Bird.
 
In my conversion....

When I had mine done it was a leakin' bastard...They replaced the packings, and added the ester oil, and wala...Charge it and it is a done deal...Cost me 80 bux to get it done...Well worth it..

I did not think that we could by refridgerant over the counter anymore??? Dale, where did you get it? Can you buy 134 ref. over the counter now?
 
Dale,
Are you saying that your suction line goes from the accumulator into the compressor manifold without any valves?

This is very odd. Can you take a pic of the fuel hoses and wire bundle out of the way so's we can see the suction line? You did remove the TB air intake tube, right?

What you should have is the front of the accumulator (thing with the pressure switch) has a steel tube angling towards the compressor. The suction line has a spring-lock fitting and a section of stiff thick hose about 6-9 inches long running into a permenant steel crimp fitting about 3 inches long. THAT fitting has a low port shrader valve and it then clamps onto another section of rubber hose and works and snakes its way down below the pulleys and eventually back up into the back of the compressor into a block known as the manifold. Somebody posted a pic showing the location. The blue cap indicates that its been converted to r134a. If you have unconverted r12, it will have a much smaller black cap, much like a bicycle tire.

I don't know if you can charge into the accumulator. I suppose its possible, but I've never heard of anyone doing it.

Has your car been retrofitted? If so, you'll have a blue label on the frame somewhere, and the high pressure port will have a red plastic cap over it.
 
r134a can be bought over the counter.

But IF you intend to charge your system yourself, get a complete set of guages, not that stupid little bicycle guage that they put into the compressor death kits (AKA retro kits). You can't properly charge without taking high side pressure readings.

Here's a link where some experts can tell you how to and how NOT to do the job:

http://www.aircondition.com/wwwboard/

As far as retrofitting without flushing... Here's the deal... IF you had a healthy r12 system (i.e. no leaks.. but then again if there were no leaks, why would you be doing the work?), they say that the old mineral oil will collect into the bottom of the evaporator and some into the accumulator (drier) and supposedly won't harm the system as it is not carried by the r134 refrigerant. But here's the thing, if your system was opened up, as you had to do to replace the O-rings, you need a new dryer as the dessicant is old and now may contain accumulated (hence the term accumulator) moisture. If you don't flush, replace the dryer, vaccuum down they system, the you risk mixing the PAG/ester oil with water. The water will mix with the PAG to form and acid which will eat the insides of the system up. With r134a/PAG, you want Dry/dry/dry and no leaks.
 
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