AC Question

[Otto Man]

Well for the first time in two years I took her out for her first long excursion (100 miles) on a hot day. The AC used to work pretty darn good. Today I noticed the air is cool, maybe cold, but there is the cycling going on when the AC (fan) stops for a few seconds and comes back on. When Ford did my heater core replacement back in February they had to unhook the AC (I think), and re-hook.
Anyway, what is going on? Do I need a recharge? The AC "pump" is a Ford replacement 5 years ago, she just sat idle for a couple years. Like I said, the air is cold, but not ice-cold like it used to be. Maybe this is normal for an older system?
BTW she runs great! Punching it at 50 with a down-shift brings a smile to my face.
Chris

[Otto Man]

Thanks Mike
Look forward to meeting you someday!
Chris

[Millertime2]

Chris, make sure you use the appropriate gauge set (R-12,134) to measure the amout of freon you have in the system to avoid overfilling. You can splurge for the professional sets ($100-up) or use one of the Autozone/Napa cheaper ones. Also its not a bad idea to stick a temp gauge in the vent to get a baseline to see where you are now and after a recharge, if its neccessary. R-12 should be around 38-45 degrees( moving/static), and if you have a R-134 conversion about 40-55 degrees.

[KevinK]

If you have access to R12, you don't need pressure gauge to top it off. You will be filling it from the low pressure side. Close all the vents but one and put the AC on high. Stick a thermometer in the open vent. 38-45 deg is a good goal for the temp. Just fill it until it gets cold. Overfilling will cause it to get warmer. On a really hot day 45 my be the lowest you will reach. Also the cycling of the compressor will be longer as you reach the correct fill amount. The compressor cuts off when the low side pressure drops to something less than 20 psi. Once it recovers, it will run again. So with more freon, it will run longer (which does the cooling). I tried to really simplify it but it's also beginning to sound inaccurate to the knowledgeable people.

[Millertime2]

Oh yeah I almost forgot, you can speed up your filling of freon by removing the plug on the accumulator and sticking a paperclip across the two pins. This will cause the compressor to run full time as you are refilling. I got that tip from a 89 5.0 manual, and place your can of freon in a warm bowl of water. However DO NOT invert the can, this will cause liquid to enter the system and can cause a dangerous situation.

[Otto Man]

Thanks for your tips gang!
Can I still get R12, or is it taboo these days?
Chris

[richsvo]

You can get it...but it's alot more expensive. You'd probably have to have a shop put it in.
Rich

[90lx86svo]

Originally posted by Chris Weber
Thanks for your tips gang!
Can I still get R12, or is it taboo these days?
Chris

You have to have a license to get R12. It is $30 a can now.
BTW, I am in the middle on installing a Sanden SD508 (universal style compressor) on my 86. I am tired of messing with the HR980 pos. It has been out of production for about 15 years and I am not going to pay $460 for a new one.

Bud