Need help with recharging my AC system with R12

[blakpete91]

Ever since I got my truck it hasn't had AC and now that summer is rolling around it's getting to the point where I kind of need it. The AC use to blow ice cold but it has sat in the garage for the past 10 years and I'm guessing the freon leaked out slowly. I took it to the ford dealer and they looked over the system and found out that it is bone dry (no freon at all). Since they couldn't recharge it with R12 they told me my only option was to convert it to R134-A which would set me back 1400 bucks. They pressure tested the system with air and found no leaks so I decided to just go on ebay and buy some R12. I bought three 14 ounce cans of igloo dupoint R12 and a can of quite lubricating oil. My truck says it takes 2lbs and 12 ounces of freon. Do I just turn on my AC and hook up the cans to the low pressure side of the AC system and charge it that way? Can someone tell me where the low pressure port is. What about the hi pressure side. Also going to pick this hose charging adapter kit from autozone.

http://www.autozone.com/autozone/ac...charge-hose-kit/_/N-255s?itemIdentifier=66748

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[cpdenton]

You can't just put freon in. You have to draw a vacuum on the system first to remove all the air that has leaked in where the old freon leaked out. Then, you want to make sure that the system can hold that vacuum for at least 10 minutes after you turn off the vacuum ump. I usuallylet them sit for more like 30 minutes. Now the question I have is this....how did the freon get out? They couldn't find any quick leaks, but r-12 is not cheap, and you don't want to lose it.
Also, you will have to find a set of r-12 gauges...they are different from anything designed for r-134. I am not even sure you can buy them any more. That recharge hose you link to will fit, but to do this right, you really need a set of manifold gauges. Then you can read all the pressures and set the system right.

The low pressure port will be next to the heater box right at the a/c dryer. The high side port should be near the drivers side battery mounted on a hose that goes up to the a/c condenser.

If it were me, I would go through and replace all the o-rings in the system first. It is cheap insurance in the long run. You could probably get an assortment of o-rings that would have enough to do the whole system for less than a can of that r-12 you bought.


Good luck with it!

 

[jaluhn83]

Honestly from the questions you're asking you may want to seriously rethink your plan. Not trying to be a ****, it's just pretty apparent that you don't have much knowledge or experience with AC systems, and AC work is somewhat tricky, not to mention regulated pretty heavily by the EPA.

First thing I would do is some research on how AC systems work and basic servicing. There's a Haynes manual on basic AC that's pretty decent.

You'll need a gauge manifold set, hoses and a vacuum pump minimum, and you should change the orifice tube and accumulator as a matter of course. The tools will probably set you back $300-400, plus another $50-75 for parts. Remember too that 95% of the gauges and hoses out there now are R-134 and don't directly fit on a R-12 port.

The quote for conversion is far far too high - it should be closer to $2-300 unless there's major problems like a blown compressor. Try an AC shop.

I would convert to 134 if at all possible, it'll save you time and money in the long run.

 

[blakpete91]

I'll admit I don't know one thing about AC. Still trying to research and learn about it on the internet. I may just take it to an AC shop and have them do it.

 

[mf7lakes]

If the A/C was still working fine and just not blowing cold enuf - I'd say "go ahead, add a lb. of freon." BUT after all this time after just sitting for 10 years, I'd have to take those cans of R-12 to a good A/C man/shop and spend the $ to get it done right. The Ford manual (at least for 1993) for F-series has 30 pages on just general servicing of the air conditioning system -- and then another 65 pages on the F-series in particular. In udder woids, the A/C system ain't no push-over.
You spend the money --- but in the end you save the money........

That being said, here's a pic of the lo pressure valve on the 1993 F350:

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[blakpete91]

Thank you for taking the time to take a picture. I've already started reading my Ford shop manual lol

 

[jaluhn83]

I highly recommend the Haynes manual - it addresses the basics that the ford manual doesn't. Also has good info on tool, R-134 conversion, etc.

With a system that's dry like that you really need to evacuate it to remove any air and especially water vapor that may have gotten in. You change the accumulator because it has a desiccant bag to absorb water and eventually it gets saturated. Water in the AC system will freeze and cause problems. The orifice tube also acts as a filter, hence the reason you change it.

Chances are good that you could just put the R-12 in, and it would work, but maybe not as well as it should. IMHO, it's better to just do it the right way.

I'd also be concerned if it's been that long since it's run especially being all original which I'd guess it is, that the o-rings and seals are deteriorated and likely to start leaking. They may be fine now, but I'd be willing to bet that you'll wind having slow leaks and have to recharge it within a year or so anyway.

An R-134 conversion will replace all the o-rings so the only original seal that'd be left is the compressor seal. Might even be worth just replacing the compressor too, they're only like $150 I think. Decent money yes, but if you have to recharge it again in a year there's $100 or so every year.... better to fix it right now.

 

[RLDSL]

I'm kinda surprised they sold you the r12. even ebay sellers are supposed to ask for a epa license number before selling that stuff, you must have found teh rare odd private person with a few old cans in their garage.
I do happen to have one of those coveted licenses , but even with that I rarely put r12 back in a system being as it''s so cheap and easy to get ice cold duct temps out of r134a, but since you have the r12 already... Here's what you need to do.
Forst off, grab an assortment of orings, and replace ALL of them. sitting empty, thos eorings are gonners, they have dried out and will not hold a seal any longer, they rely on the refrigerant bearing mineral oil to keep them moist to hold a seal, with nothing going through, they with be crispy critters. Unfortunately this will also hold true for your compressor seal. Now if youknow for a FACT the compressor was good, you can just replace teh nose seal on the compressor and be good to go, but if not, get a NEW ( I said NEW, not repainted..oops, I mean rebuilt compressor rebuilts rarely last more than 2 years and performance is usually dismal and they usually cost more than a new one , do not shy away from chinese clones, they will generally outlast stock compressors )
Consider popping a variable orifice valve in there, they do wonders in a r134a system, in an r12 system, you'll be hunting a nut warmer

Lastly, you are only a state away, i'm right here in central Arkansas and have all the goodies needed to fix up an ac system any way needed. If you want to take a little trip and stop by for a visit, we can get that ****** running so cold that you'll be blowing out snotcycles

Now out to go figure an electric problem with the ac on a 97 ******

 

[jaluhn83]

And if you're going to go to that much work why not just go to R-134? Beats having to do it all over again whenever it eventually gets low again.

 

[riotwarrior]

Too bad yer not closer, I've got the vacuum machine for drawing the vacuum, I've just gotta get a set of gauges to work with. Then I'm golden.

Big ass commercial vacuum machine too ROFL!

Oddly cannot find the image of it I had

 

[icanfixall]

Your getting into something that will blind you if any freon blows in your face. A properly charged system with R12 will have 50 lbs on the low side running and around 250 lbs on the high side running. A vacuum must be pulled on the system since some dealer filled the system with air pressure.. Thats a big mistake right there too. But lets move on. A vacuum pump is easily made from any refrigerater freon pump. Even a water cooler freon pump will work. All you do is weld by braseing or solder some fitting on the two lines. One is suction and the other is pressure. Cut loose the pump from any broken refer and find these copper lines off the black can. Simple. Now you need the R12 recarge manifold gauge set. Any real ac supply shop will have these or ebay it. Any refrigerater repair shop will have the pumps already cut out of bad refers too. Probably around $25.00. Much cheaper than the factory ones that can run as high as $800.00. The manifold comes with three hoses all differant colors to tell you where they connect to the system and vacuum pump. Suck down the system and close the valves to the manifold. Let it set for 30 minutes. 27 inches of vacuum is what you want but nothing less than around 23 will do. Even leaving in overnite is not a bad thing to do. There is a special can adapter needed to puncture the cans so the freon can flow into the manifold and then into the system. One can may not cause enough pressure for the pressure switch to activate the ac electrical clutch on the compresser. A jumper can be made but lets not go there yet. After one can is in close the valve and remove the mt can. Set up another can and send that into the system. The pump will be running now. Watch the low side pressure drop till its around 10 lbs and close the valve. Remove the mt can and set up the third can. Watch as you add the lst can. Try to keep the low pressure side no higher than 50 lbs. Really no need to connect the high pressure lines to the high side port because there is nothing you can do about that pressure. The engine should be reved up to around 1500 rpm too. If at any time you see the return line to the compresser getting frost on it you have too much freon in the system and some must be removed. We are not allowed to vent to atmosphere but we do anyway. I strongly urge you to wear a full face shield just in case something blows. Replacing the orface tube and the dryer is good sence too. Look at the ac compresser clutch nut. If any oily dirt is seen around that you pump seal is shot and all this freon wil leak out in no time. Replacing the o-rings on all the freon lines is a great idea too. Theres only 5 or 6 of them and they are cheap and maybe free at the place you buy the recharge manifold from. Most of all be careful around compressed gas like this. When the system is shut down both sides of the system will neutralize the pressures. The low and high sides will be the same in a short time. Wear gloves too. Freon is about 200 degrees below zero and its going to burn you like it was hot.. When you remove the lines from chargeing do it fast so very little freon leaks out on you and mother nature.. Having never done this work and the amount of stuff you need I think its better to take the freon to a ac shop and have them do the work. Now a note about any ac shop. The only reason your there is your charge leaked out. No shop can recharge a system that has a leak. So its a catch 22 thing. They will find a leak somewhere and charge you to fix it. Or at least die check the system to insure they don't get a ticket for doing work thats not epa certified.

 

[HS108]

Another question to ask your self is are you gonna charge this thing up then let it sit for another 10 years??. If thats the case Id just get the retrofit kit and throw a charge in there because as long as you make it through this summer who cares right. I know a lot of people are gonna tear me up for saying that but lets be honest here.. If you plan on using the truck more often now, then by all means take it some where and get it done right,

I was born in TX and lived there for 22 years, I KNOW the importance of AC, sometimes the 260 AC just dont cut it (2 windows, down 60MPH) for those wondering lol

 

[cpdenton]

that is really a good point about future recharges.


You Could take up RLDSL on that offer to come here and let us have a go at getting right for you. We are both licensed and have the knowledge to get you riding cool.(I will admit he probably knows a LOT more than me!)

On another note about the cost to retrofit your system. I did mine for about 10 bucks in fittings and about 30 in freon and oil. So, I think they must have been planning on changing the compressor or something, because freon is not that expensive. I recently bought a 30 pound jug at advanced for $124.99.

 

[blakpete91]

Update- I took it to my friends dad who has been in the AC business for 19 years and he helped me out. Vacuumed out the system, replaced the oriphace tube, and put all new o-rings, then recharged with r-12. It's been two days and it's still blowing ice cold.

 

[HS108]

nice!!!!!