Am I adding this right????

Ok my 89 Aerostar says that to recharge the system use 3.75 lbs of R-12.

If I'm adding right (16oz to a lb) then it would take 60oz

The coolent that you buy now is in 12oz cans. So if I divide
60oz by 12oz that comes to 5 cans.

Now the cans say use 10% less. So that would make 60oz-6oz=54oz

So 54oz / 12oz = 4.5 cans.

But the kits for one recharge come with three 12oz cans which makes it 36oz.

So am I 18oz short in my recharge?? (54oz-32oz=18oz)

JaY

"This is too hard, It's making My brain Hurt" - Chris Farley.

 

take hacksaw to auto parts store andy buy 1.5 cans.



i never was very good at math story problems in grade school
did i fail JT?

 

Uhm, you are way off.Your math is good, and yes you need less R-134a to get the job done, but straight swapping out is not that simple, don't let anyone telly you otherwise There are things that must be done to ensure a correct changover. Second off, this only works if you have a completely evacuate AC system. Thirdly, never refill an AC system based upon the volume of the system, that is how our mechanic RUINED our AC system in our Aerostar.


R-134a will take a different quantity of refrigerant, it takes slightly less to get the roper amount, so if you put 60 oz. ofR-134a in your system, you would very likely blow a hose or seal. According to your calculations, ou do need to use 50 Oz, BUT chances are that amount is incorrect. You need to measure the amount based upon pressure. Buy at least one more can thatn you need, chances are it will come in handy one day.

Have you replaced the accumulator? How well do you need the AC to work? Have you replaced the Orfice tube? Do you have a thermoter to test the results as you add refrigerant? Does the kit come with oil? Have you had a shop remove all the old R-12? Have you vacuumed the system out with a vacuum pump for 45 minutes? Have you completed the 5 minute leak test?

To be quite honest, I think you need to read up on how AC service if performed. Make sure you do this right, and your AC repair will work flawlessly. Try to add by the volume capacity of the system, and say goodbuy to your hose and seals. Maybe wear out the compressor too. Haynes has a fairly descent book on the subject.

Tools you will need:
AC fitting tools (little plastic rings that let you open the spring fittings on a Ford AC system)
Thermometer (a good accurate one)
Manifold Guage set (very highly recommended)
Orfice tube removal tool
Ford AC system seal set

 

I think he already has the "orifice tube removal tool". Needle nose plier work extremely well, unless some clown has inserted the tube backwards, as was the case in my first attempt at repairing my A/C.

I don't know how critical it is, but the orifice tubes are different for R12 and R134, and also for the front and back unit. The front takes an orange one and the back uses a brown one.

Also different is the setting of the pressure switch that is located on the accumulator. The switch is adjustable, but I have no idea how you would change the setting from R12 to 134. I just went and bought a new one that was preset for a system that had been converted to 134.

My system called for 4lbs (64oz) of R12. I used 85% as a basis for the charge of 134. That comes to about 54oz and change. I used 4 cans (48oz) and achieved roughly 50, 40 and 30 degrees vent temp at idle, 30mph and freeway speed respectively.

 

Four (12oz) cans works well for a dual air system. Getting the last can to go in takes a while. I found it was easier to hook up the last can, leave it hooked up and take a short drive. (This is with the can in the upright position.)

 

Or dunk the can in some warm water.

 

Khantyranitar:

Will like I posted in the other thread.......
*********************************************
"Well I took all the Hose connectors loose on the A/C in the Wife's Aero. On the 5 Connectors only 2 had the O-Rings replace to the Green ones. The other 3 had the Black ones. So when I had the system repaired and charged He didn't change all the O-rings to the Newer green ones. When I removed the Orifice Tube (Filter) it was spotless."

Ok,
"Replaced all O-rings in all the A/C hose connecters. New Orifice tube, Put everything back together, Hooked up my gauges and attached my Vacuum pump. Run the Vacuum for 1 hour. Chosed valve. Turned off vacuum.
Checked gauge (29lbs Vacuum), let set for another Hour. Checked again. Still setting at 29lbs Vaccum. So the system is sealed."
****************************************

What I was trying to do was make it easier for ones trying to do it themselves. All I was asking was for a straight & simple answer..does anyone know how may 12oz cans for a single A/C unit no/aux in a Aerostar?

I feel that the sticker under the hood that says 4.50 lbs for A/C w/Aux and 3.75lbs A/C no/aux is there for a reason. And for you to say "You need to measure the amount based upon pressure" makes no sense at all. This is what the mechanics that will work on the A/C use to recharge it.

If we're going to be quite honest here.. It would Help out more people here if you would quit trying to show off technically and put it in such a way that the rest of us shade tree mechanics can understand.




Khanty, I've never met you or know who you are but, for some reason we seem to rub each other the wrong way. I have nothing against you and more than likely if we met and didn't know one another from here we'd be friends. Sorry for anything I say that is taken wrong.

Now...Back to the program,
JaY

 

Jay:

My experience is that anywhere between 70% to 90% of R-12 capacity will do for R-134a. Four 12oz cans should be perfect for your case. Sorry I didn't answer sooner, but somehow I thought I did! Must be that old age thing again.

 

Jay,

You can do it emperically:

Install a couple of cans first. If your A/C will run in this state, it will most likely cycle on/off often at idle. If so, or if it doesn't run at all, add one more. To be safe, I would rather slightly undercharge it than overcharge it, so I would stop as soon as it stops cycling at idle. If I hear it cycling too much at normal cruising speed, or find the air not cold enough, I'll add a little more. But I've been told by A/C mechanics that slightly overchraged (within a can's worth) should not hurt the system.

So far, my Mustang has been working for 13 years since I did this. My Aero still has a leak in at least one of its fittings, so I'll have to get into it to replace the O rings again. This means having to evacuate the system again, but I'm not sure if I have enough refrigerant in my supply, which was why I was asking about where to get more R12 compatible coolants. Changing completely over to 134a sounds like a real hassle.

I know the earlier Freon cans were the puncture type, so you have to use the whole can once you pierced it with the needle on the clip-on valve. The replacement I used was more like a spray can, so when you turned the needle down, it just pushed a little valve in the can to release its contents. When you pulled the needle back, it would seal, so you didn't have to use the whole can in one operation. I'm not sure how the latest cans of refrigerants are packed.

 

Ah I see the older cans were somewhat like the valve on a propane torch canister.

The newer cans (of R134a anyway) use a piercing needle valve you screw the valve onto the can and turn the valve fully clockwise the needle pierces the thin steel on the top of the can.

If you decide not to use the whole can you turn the valve completely clockwise and can store it for later use.

 

Actually, underchargeing is far more stressful than slight overchargeing. A slight overchargeing may put a bit more stress on the hoses and won't cool efficienctly, but an undercharged system doesn't carry lubricant as well.

About the orfice tool removeing with needle nose pliers is generally pretty good, BUT, it is easier to break the tube. If the tube breaks, you will need a special and more expensive orfice tube extractor.

 

I used a pair of forceps to remove it. Well I put in 3 cans. I put a big box fan against the grill and ran the van for about hour. With it on norm it was reading 62 on Max it was 51. I don't know how normal that is but it was a lot cooler that the 101 it was outside.

JaY

 

Those are good numbers about where they should be.