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The wife's complaining it's to hot and wants the air on the mustang working. It's an underdash unit, and every thing is there and hooked up. The evaporator fan works, although a wire to the compressor is disconnected, so I do need to hook that back up.

Before I go spend money on having the system charged, what kind of things should I look for besides the normal stuff like cracked hoses disconnected wires, etc.?

Is there any way to verify if a compressor or clutch is bad? How about the dryer or condensor?

Thanks
 

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I'm certainly not the last word here but take it to a a/c shop, have the pull a vacuum-- you'll probably have to hook the compessor electrical up to do so- If it won't hold a vacuum, it's not going to work anyway and will leak. If you are using R-12 freon (more expensive than gold and Gray Davis's worst enemy) you are better of not putting it in until you know the system holds vacuum and has a decent chance of operation. If you are using 134a-not terribly expensive, you can put a can of that stuff in, maybe it's work. If not, you haven't wasted much. You can buy some of that stuff that has a green dye mixed in that't tell you if/where the leaks are.

Things to check-besides compressor, water valve-so the heater doesn't come one with A/c,

Good luck-I'm still trying to get mine to cool but I've narrowed it down to 6 or 7 things to try.

J. Boggs
 

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If you have the stock style compressor, check it for proper refrigerant oil level. If you are going to convert to R134, don't bother it needs to be changed anyway. If you have access to a pump and the system charge is depleted, a good move is to evacuate the system and see if it will hold a vacumm. Typically, you would let the pump run for perhaps 30/45 minutes which also gets out the moisture, close off the system valves and see if the vacuum holds. I think a minimum of 15 minutes is desired for no drop in indicated vacuum.
 

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A quick & easy way to check the compressor is by performing these three tests;
1 - You can do this on a workbench. Run the compressor with a drill motor while holding your thumb on the suction port. Stop the drill. If suction doesn't hold your thumb when the drill stops, the valve plate under the compressor head needs cleaning.
2 - Hook a high pressure guage to the discharge port. Run the compressor at 1500 RPM for no more than 15-20 secs. A good compressor will be able to pump up to 200 psi in 15 secs or less.
3 - Drain the compressor oil. It should be transparent and free of particulates.
Don't waste time with the dryer. Replace it regardless. Other than leaking or being plugges, condenser should be ok. If you are going from R-12 to R-134a, you should seriously consider replacing it with a high effeciency unit.
 

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I'd go ahead and convert to R134-a or find someone that has Freezone.

If I were you, I'd add the R-134 myself. I just did this, using a digital thermometer. I added a can of R134, then 2 4.5 Oz cans of oil. Then I added very slowly in 15 second intervals R134. My thermometer started at 106 degrees, and when I was all said and done, it read 61.7! Helluva a drop. I did a couple more 15 second shots, and it started to go up (to like 62.5), that is when I stopped adding.

I do not believe that an AC shop will find the optimal (lowest) temp, which does take time. I have heard that R134 does not cool as well as R-12, but I am satisfied with this application.

I had it vacuumed for an hour, paid 50 bucks for just that. Then did the rest myself.

I did not change the dryer, because it's a royal PITA.

Marty
 

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Since its a underdash unit you can use 134a and it will work fine. The underdash units have a huge evaporator and will cool efficiently. Check your lines and replace them if they are bad, they dont cost that much anymore. Remove the compressor and drain the oil out through the oil plug on the top. Measure the oil that you removed and replace that amount plus 2 oz of synthetic pag or ester oil for any seepage over the years. YES, DO REPLACE THE DRIER, it should only cost around $20.00 and will save you a lot of heartache down the road. Be sure to vacuum the system for a couple of hours. Also the smart thing to do is tape the ends of the open system when you have components removed, this will prevent dirt and moisture from entering the system until you get it re-sealed.
I was able to replace the condenser and drier on the 62 for a minimal amount and re charge with 134 and it will form icycles on your nose.
 
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