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Discussion Starter · #1 ·
First off I could not find an appropriate area to post questions about a/c, so admin feel free to move if needed.


I have a 89 CSX that I recently bought from the original owner and he had it converted over to 134. This car has sat for 9 years before I bought it. The a/c does not blow cold. With the engine running you can see the a/c clutch cycle like its low on freon. If I bypass the low pressure switch the compressor will remain running with the clutch engaged, but barely cold air comes out the vents (not an HVAC control issue as you can switch doors with no problem)

I hooked up a a/c pressure gauge to the port on the compressor and with the engine running but clutch not engaged it will read high pressure (sorry dont remember the number but in the yellow). When the compressor kicks in the indicated pressure drops to zero.

Of note, my a/c pressure gauge has a trigger handle so when the clutch is not engaged (pressure reads high) if I squeeze the pressure gauge trigger, I will get pressure out of the gauge hose. With the engine running and clutch engaged (pressure drops to zero indicated) and I squeeze my a/c gauge handle, I get VERY little pressure coming out of it.

Is this lack of pressure when the compressor kicks in a sign that my compressor is junk, or an obstruction in a line?

This winter my plan is to replace everything that has parts available, vacuum the system down, and then service it.
 

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I've always charged up my A/C on other cars using the cans that come with a hose and dial gauge.
You dial in the ambient temperature outside (70-90 degrees), connect the hose, put the A/C on high and pull the trigger on the hose/gauge unit.
Then you wait until the pressure builds up on the gauge to a range of 25-55 psi (175-375 kPa.)
Why not try recharging with this:
 

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Discussion Starter · #3 ·
I've always charged up my A/C on other cars using the cans that come with a hose and dial gauge.
You dial in the ambient temperature outside (70-90 degrees), connect the hose, put the A/C on high and pull the trigger on the hose/gauge unit.
Then you wait until the pressure builds up on the gauge to a range of 25-55 psi (175-375 kPa.)
Why not try recharging with this:
I've always charged up my A/C on other cars using the cans that come with a hose and dial gauge.
You dial in the ambient temperature outside (70-90 degrees), connect the hose, put the A/C on high and pull the trigger on the hose/gauge unit.
Then you wait until the pressure builds up on the gauge to a range of 25-55 psi (175-375 kPa.)
Why not try recharging with this:
Tonight I bought 4 12oz cans of 134 and have a hose similar to what comes on that A/C pro can.

I have been watching videos and it sounds like the expansion valve may be fubar. I just ordered a new valve and will try that and see what happens (I already have a couple set of seals). I do have a legit a/c manifold gauge set and tomorrow I will hook it up and read both the low and high side pressures. If I have to replace the expansion valve, I have a vacuum pump so I can draw it down and use the manifold set to service it.

I figure worst case I am looking at a new compressor, hoses, condenser, evaporator (the one item I hope is not bad), drier, and expansion valve. Most under hood parts are easy enough to change.

If I have to replaced those parts, I think I will take the cars hoses to a hose shop and see if they can just cut the ends off and replace the rubber bits vs buying aftermarket hoses.
 

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85 New Yorker 2.2 T1, 89 LeBaron Convertible 2.5 T1
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All three TD's I own now took a looong time to charge, then they took about a day to work. I have the high-side and low-side reading A/C kit, so I watched the high side on the only one that was retrofitted with the right fittings. All three are working now, but I ended up putting in about 12oz one day, then another 4oz the next day. Of course the cans got cold and didn't want to push R-134 into the system, but just switching cans wasn't enough for me.

The fact that you get high pressure readings means the compressor is probably working fine. It sounds like everything is working correctly and just needs the correct charge.

Oh, and I do suggest getting a UV light and dye kit. It answers many questions. (-:
 

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What were/are your gauge readings with the A/C on Max High?
All of the expansion valve issues I have seen on Chrysler vehicles over the years are that it sticks closed and the low side will go into a vacuum.
 

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Discussion Starter · #6 ·
So I decided to go the cheap route and added a can of 134a ($6 and change at Walmart. Glad to report system blow cold air now.

I will monitor it over the next couple months to see if it has a slow leak. But I guess one 12oz can after 9 years of not running ain't too bad.
 

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So I decided to go the cheap route and added a can of 134a ($6 and change at Walmart. Glad to report system blow cold air now.

I will monitor it over the next couple months to see if it has a slow leak. But I guess one 12oz can after 9 years of not running ain't too bad.
Probably was bone dry and needed a complete recharge.
Excellent news!!
 
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Discussion Starter · #8 ·
Probably was bone dry and needed a complete recharge.
Excellent news!!
I am just afraid the hoses will allow the 134 to seep out. if that happens then I guess I will just take the hoses to my local rubber hose shop and see if they can take the metal ends off and make me new hoses.
 

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I am just afraid the hoses will allow the 134 to seep out. if that happens then I guess I will just take the hoses to my local rubber hose shop and see if they can take the metal ends off and make me new hoses.
I'm pretty sure you can buy replacements, and that might be cheaper.
 

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Discussion Starter · #12 ·
No dye yet. Need to get the car road worthy so I can use the a/c and monitor it. Should the charge drop I will either add the dye or just basically put a whole new system in.
 

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I would suggest adding dye the next time you need charge the system. That way you only need to replace the part that is leaking. These A/C system components were still fairly durable on these cars. I have owned and worked on quite a few over the last 30 years. When my son bought his '87 GTS 3 years ago the system had been retrofitted but didn't blow cold. Charged it with freon & dye and found the condenser had a small leak. Replaced the condenser and expansion valve and the system works great. When opening up a system it is imperative to put a vacuum on the system before you add freon. It removes any moisture in the system and will let you know your system is sealed.
 

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Discussion Starter · #14 ·
Yep. I know about a/c systems and how to maintain them. My first gauge I used did not read.right and I do have the manifold and vacuum pump if needed.

After a month I will put the gauges back on it and see if the pressure is slowly dropping.

Dye.is great if you know.you have a leak, I do not know yet so not worried about it. Beside 32 year old a/c can be allowed.to fail.
 
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