Sauna on wheels! Can I recharge my 97 stang with 134a?

[Dr. B]

Does anyone know what type of refrigerant is in 1997 Mustang (3.8L)? To my knowledge this is the 1st time it needs to be recharged. I bought a do it yourself kit at walmart but didn't want to screw anything up. Any advice is much appreciated!

[lx mike]

Look on top of your rad or up front there. usualy there's a sticker that tells you.

[Rev]

My bet is it's 134A. Owner's manual might say which it is. Be glad that you can even get refrigerant at all. Here in Texas, you have to be a certified refrigeration mechanic to even buy it.

Rev

[Dr. B]

Thanks for the response. There's 2 valves. One by the firewall. One by the radiator.

The firewall valve has a psi of 100...Im assuming that's the high pressure valve and I should avoid it.

The valve near the radiator I cannot check the pressure because the pressure gauge will not fit on it. Perhaps Im looking at the wrong area?

Does anyone know where I can find an online A/C diagram for a 1997 V6 mustang?

Anyone know a trustworthy mustang mechanic in midlothian, VA?


Thanks again for your advice!

[~The Jester~]

Dude, don't worry about "which line is which". Two different size fittings, they'll ONLY fit where they're supposed to. Follow the directions on the recharge kit, and you'll be fine.

YES, it's 134a, but the only thing I want to caution you on is this. That is a SEALED system. Now it needs a recharge? Freon does not "just go away". You have a leak somewhere, and you need to find it, and fix it, before you recharge the system. If not, you might as well just send the money you spent on that recharge kit over here to Ohio.

With me? The stuff just doesn't "go bad". It went SOMEWHERE. Find out where first, before you waste your time and hard earned cheddar.

[Dr. B]

Thanks Jester, will do!

[Maroon 5.0 LX]

Do as The Jester suggests.
But, NEVER put freon in the system with "Stop Leak" in it. It will eventually screw up the system. Find and fix the leak(s) to cure your problem.

[~The Jester~]

Originally Posted by Maroon 5.0 LX

Do as The Jester suggests.
But, NEVER put freon in the system with "Stop Leak" in it. It will eventually screw up the system. Find and fix the leak(s) to cure your problem.

Yeah, instead of "stop leak" they should call it "stop your system from working" hehehehe. BAD stuff, good idea, but it just doesn't work. Fix it the right way, and you'll be many dollars ahead.

[grey88gt]

I would recommend putting dye in the system with some more freon. Then find and fix the leak. (You will need a black light to see the dye) Look at the front seal around the clutch area of the compressor. Look at all the hose connections and around the compresser for signs of oil, if any is found that very well could be your leak. If your system needs to be opened up to repair, replace the dryer (acumulator/reciever) over buy the evaparator core .Have the system vaccumed to remove all the mositure, before putting freon back in. Dont overcharge the system when putting the freon back in, a little to much freon in a 134a system is just as bad as haveing none at all. Try to get someone with a good set of AC gauges to put in your freon, instead of just using the single low side kit. The low side should be around 25psi and the high side should be 150-250 psi depending on outside temp and how much air is moving thru the condenser, with engine rpm around 1000-1200. Like the Jester said, you cant hook up the hoses wrong becuase the fittings are diffrent sizes and DONT use the stop leak. Ive been doing ac work for along time, (not claiming to be an expert by no means) but know how to make cold air. Hope this helps out, sry such a long post.

[Philossifer]

Originally Posted by Dr. B

Does anyone know what type of refrigerant is in 1997 Mustang (3.8L)? To my knowledge this is the 1st time it needs to be recharged. I bought a do it yourself kit at walmart but didn't want to screw anything up. Any advice is much appreciated!

Your A/C system uses R-134a.

If it needs refrigerant, you have a leak! My suggestion would be to undo all the fittings, clean them with refrigerant oil, replace any damaged o-rings if necessary and re-connect the fittings using a product called "Nylog."
Those pesky o-ring connectors will never leak again. (((AND I MEAN NEVER)))

Before you recharge add two ounces of "Ester" refrigerant oil into the accumulator (or any hose that can be easily accessed) then pull the system into deep vacuum for at least a half-an-hour. When you recharge, do it slowly until you get the coldest temperature out of the vent without having the High side pressure exceed 2.5 times the ambient outdoor temperature. While charging you should have the engine idle at about 1200rpms, the windows down, with the air on MAX A/C and the fan on high.

So if it's 90 degrees out, you (DO NOT) want the high side pressure to exceed 225 psig on the red gauge.
Example: (2.5 x 90 = 225 )
As you're charging, you might have to spray some water on the condenser if the high-side pressure goes too high. Spray water on it, let it equalize and continue to charge.

Then, when you've got the charge correct, roll up the windows and turn the fan on low. Watch the blue (Low side) gauge. When the pressure drops to about 19 psig, the compressor should cycle off. If it cycles off at a higher pressure than 19 psig, the system will not cool down enough and if it cycles off at a lower pressure than 19 psig, your evaporator will ice up. To adjust this, there is a cycle switch on the accumulator. (Black or silver can on the firewall) Unplug the harness from the cycle switch and inside the connector (on the switch) there is a recessed screw. Turn the screw counter clockwise (outward) to lower the pressure set-point of the cycle switch or turn it clockwise (inward) to raise the pressure set point of the cycle switch. Remember, you’re looking for the compressor to cycle off at about 19 psig on the blue low side pressure gauge!

If you want Ice Cold A/C that will last for a long time and you don’t want to do permanent damage to your system; It needs to be done right. So many people just suck in a few cans of refrigerant without repairing leaks, adding oil, monitoring pressures or pulling a vacuum......and the A/C might work fine for a while……..but over the long haul, it can and will cause much damage! Personally, I'd take the Wal Mart kit back. In the trade, A/C techs call these "Death Kits"
Good luck,
Phil

[grey88gt]

Not trying to start anything with you Phil, I agree on everything you stated, except for the 19psi on the low side. Ive seen alot evap cores freeze up at that psi. May be an exception around here because the humidity is so high. Never the less great instruction here on how to properly fix an AC system.

[Philossifer]

Originally Posted by grey88gt

Not trying to start anything with you Phil, I agree on everything you stated, except for the 19psi on the low side. Ive seen alot evap cores freeze up at that psi. May be an exception around here because the humidity is so high. Never the less great instruction here on how to properly fix an AC system.

grey88gt,
Well, you're gonna' have to argue with the automakers on that one! Many R-134a cars have pre-set cycle switches that can't be adjusted and guess what.........they're set to cut out the compressor at anywhere between about 19 and 22 psig.

If you're system is charged with R-134a and the evaporator is freezing up with the cycle switch adjusted to cut-out at 19 psig, then more than likely the system is slightly undercharged!

Here in Michigan the humidity is pretty high too. Never yet had an R-134a evaporator freeze up at 19 psig.

Sure you're gauges are accurate?
Phil

[grey88gt]

Ill have to check them the next time I do an AC job. Again Iam not trying to argue with you or anyone else, just telling what I have ran across at times. I did repair a 96 F-250 last week and it did not have an ajustable low preasure switch and it cycled at 24 psi, and had ice cold air. No biggy just seen a few of them do it, most of them have been farm trucks and tractors that have done, heck who knows the evap cores may be dirty, espically on the tractors.