'91 FJ80 AC Recharge (R12) (1 Viewer)

[YendraBuilt]

I've searched and read every thread dealing with to convert (R134a) or not to convert. There's several folks in the area with R12 for sale on CL, figured it's easier to keep using that than it is to convert...for now.

I'd guess that my 91's AC system is completely original, it still works OK when on the HWY, doesn't keep up around town, and there's clearly fluid in the viewing window. I really don't care about AC, but, the wife most definitely does. Need to keep my hot wife cool so we can take the FJ80 instead of her '17 Heep Grand Cherokee...

It seems shops don't want to mess with R12, so it looks like it's up to me to recharge myself. I figure that if the system still works and still has refrigerant after 26yrs and 210,000 miles, I'll just add more and be good for awhile longer.

What's the process for an R12 recharge? What's needed to fill 'er up and make sure it's not overfilled? Is there really a better, easier, cheaper way to convert to R134a? Or is my master plan sound?

 

[1972FJ55]

Are there bubbles in the sight glass when the A/C is on? If so, it's low on charge. You can find R12 on craigslist. Slowly add refrigerant to it through the low side port until the sight glass clears. If it is low, that means there's a leak somewhere. Hopefully a slow leak where you only need to recharge every couple years.

 

[ZackR]

Is it difficult to convert from R12 to R134A? If not that's what I'd do, and in the process I'd pull the evaporator for a deep cleaning as well as the blower fan. I was amazed how much crap I found in there.

Recently did that on mine and went from zero AC to ice cold, enough its uncomfortably cold on full power, even at 90 degree ambient temp.

 

[YendraBuilt]

Are there bubbles in the sight glass when the A/C is on?.

There are some bubbles in the window when running, doesn't look too bad.

Is it difficult to convert from R12 to R134A?

If the system wasn't operating at all, clearly had no refrigerant, or had visible or audible issues - I'd convert to R134. Planning on just recharging since it appears it's only low. Retrofitting to R134 would take vacuuming the system and some new fittings to add the R134. Even if a single can of R12 costs me $40 off CL, it's still cheaper and easier to add the old rather than convert.

Does anyone know exactly how to add more R12? AC is one of the few items I've never serviced on any of the 9 vehicles I own.

 

[BILT4ME]

There are some bubbles in the window when running, doesn't look too bad.



If the system wasn't operating at all, clearly had no refrigerant, or had visible or audible issues - I'd convert to R134. Planning on just recharging since it appears it's only low. Retrofitting to R134 would take vacuuming the system and some new fittings to add the R134. Even if a single can of R12 costs me $40 off CL, it's still cheaper and easier to add the old rather than convert.

Does anyone know exactly how to add more R12? AC is one of the few items I've never serviced on any of the 9 vehicles I own.

You need to add it to the LOW side port on you truck. If you don;t have a "fill hose", you may need to buy a set of R12 gauges on CL as well for CHEAP. ($10). Then, it's a matter of watching the pressures and reading what it tells you in the manual.

When it comes time, I would eventually switch to R134, you will need to change the compressor, receiver/drier, and the expansion valve. Then you vacuum it down for a long time (like overnight) to evaporate all the R12 oil from the system. Then you fill the compressor with the correct amount of R134 PAG oil, install the new components, and charge away.(With you new R134 compatible set of hoses. Don't forget to install your R134 AC adapter kit.

If you still don't know, YouTube it.

 

[jakerudy]

There are some bubbles in the window when running, doesn't look too bad.



If the system wasn't operating at all, clearly had no refrigerant, or had visible or audible issues - I'd convert to R134. Planning on just recharging since it appears it's only low. Retrofitting to R134 would take vacuuming the system and some new fittings to add the R134. Even if a single can of R12 costs me $40 off CL, it's still cheaper and easier to add the old rather than convert.

Does anyone know exactly how to add more R12? AC is one of the few items I've never serviced on any of the 9 vehicles I own.

If you don't own a gauge set - on a hot day park it in the sun with the windows open and a/c on full blast. Slowly bleed vapor phase R-12 into the suction line until you don't see bubbles in the sight glass. That should get you close.

 

[ZackR]

It looks like you can use an adapter from a R134A hose to a R12 hose. Then you could use either a R134A manifold to add the refrigerant or one of those little hose setups that come with the refigerent cans at the parts stores.

 

[SteveH]

Ebay has very cheap R12 charge kits. I added 1/2 can of R-12 to my 'barely cooling' FJ62 and it now puts out air that is 40F below ambient.

Tip - before you add the R12, open the valve for a second to purge the line of air - there's no sense putting air into your A/C system. After you do this purge, quickly connect the hose to the low side port, leave the can upright (not upside down) and let it go into the system. Have a bucket of hot water nearby into which you can put the can when it frosts up. This will speed up the process. Watch your sight glass and your center vent temps (get a probe thermometer) and when the bubble are mostly gone and the center vent temps drop to the mid-40s, you're good. The engine should be running with the A/C switched on, and fan on high, when recharging.

 

[BILT4ME]

It looks like you can use an adapter from a R134A hose to a R12 hose. Then you could use either a R134A manifold to add the refrigerant or one of those little hose setups that come with the refigerent cans at the parts stores.

Don't want to use a set of R134 gauges as one side won't adapt to the R12 and secondly, you don't want the PAG oil and R12 oil to mix. They don't play well together.

 

[RiverCityDave]

There are some bubbles in the window when running, doesn't look too bad.



If the system wasn't operating at all, clearly had no refrigerant, or had visible or audible issues - I'd convert to R134. Planning on just recharging since it appears it's only low. Retrofitting to R134 would take vacuuming the system and some new fittings to add the R134. Even if a single can of R12 costs me $40 off CL, it's still cheaper and easier to add the old rather than convert.

Does anyone know exactly how to add more R12? AC is one of the few items I've never serviced on any of the 9 vehicles I own.

The service manual states that "some bubbles present if cooling is acceptable can be considered the normal operating condition"

And you do NOT need to replace the compressor to convert to R134.

You change the mineral oil to PAG which requires a flush (easy, DIY) and any leaking O-rings (5.50 for the entire pack from RockAuto). Additionally you need the fitting adapters (8.00 same), you also need a new dryer (which is 11.00 from RockAuto) and you MAY want to update the condenser, (57.00 RockAuto).

Total Cash out of pocket before Coolant -

81.50.

R12 cost ???
R134 Cost 4.99 can at Walmart. You need three cans, so 15.00.
PAG Oil Cost 6.00

21.00 for the stuff that flows. Get the manifold for free from Auto Zone Tool Rental. Spend a few hours doing work, and boom. Ice Cold. Less than 100.00 total outlay, IF you replace the condenser.

I would also point out that if it gets cold at speed, but not at idle/slow speed, your fan probably isn't drawing enough air across the condenser.

 

[BILT4ME]

The service manual states that "some bubbles present if cooling is acceptable can be considered the normal operating condition"

And you do NOT need to replace the compressor to convert to R134.

You change the mineral oil to PAG which requires a flush (easy, DIY) and any leaking O-rings (5.50 for the entire pack from RockAuto). Additionally you need the fitting adapters (8.00 same), you also need a new dryer (which is 11.00 from RockAuto) and you MAY want to update the condenser, (57.00 RockAuto).

Total Cash out of pocket before Coolant -

81.50.

R12 cost ???
R134 Cost 4.99 can at Walmart. You need three cans, so 15.00.
PAG Oil Cost 6.00

21.00 for the stuff that flows. Get the manifold for free from Auto Zone Tool Rental. Spend a few hours doing work, and boom. Ice Cold. Less than 100.00 total outlay, IF you replace the condenser.

I would also point out that if it gets cold at speed, but not at idle/slow speed, your fan probably isn't drawing enough air across the condenser.

Ah, yes, you are correct. I did mine (non-Toyota) because it crapped out and I was swapping compressor anyway. But yes, DO need to flush the system.

 

[SUMMIT CRUISERS]

Freeze 12 is another direct replacement for R12. I've had good luck with it.

 

[Nostradamus]

I have an 87 BMW that runs R12 that I rebuilt the AC in back in like 2000 with parts for Arizona Mobile Air, and my FJ60 was retrofitted by the PO to R134A. I charge them both as needed when they stop cooling well, or in the spring each year. I used to live in Scottsdale AZ, and the R134 conversion handled that heat just fine. It has stock sized evap and condenser, and aftermarket sanden/seltec-type rotary compressor and the newfangled hoses for R134 (assuming compatible o rings as well, but who knows). I THINK the expansion valve is the OEM spec one, but I'm not sure. The receipts for the work don't show a new one being billed, so that's what makes me think the OEM one is still in there.

I have a set of manifold gauges for R12, and have the R134A adapters that go on the hose end, so I use the same manifold set for both vehicles and both refrigerants. Just download a pressure/temp table from the interwebs for R12 and charge to the pressure shown for your ambient temp at the time. If the compressor isn't engaging due to the low pressure cutout switch (usually located near the sight window somewhere), just jumper it to the + batt terminal and it will engage. As mentioned above, charge via the LP port. Be sure you get one of those groovy can-tapper things that goes on the top of the can that will allow you to seal off a partially used can for future use (it won't seal it indefinitely, but you should be able to get 6-12 months of storage out of it). If you were in Seattle, I'd have you drop by and charge it up for you.

When R12 started getting scarce, I scored 3 partially full 30lb cylinders of it off of fleabay. Had to provide a copy of my MACS certificate (which is required to purchase R12 [technically ]), which I obtained by taking an online class and test for $15. Easy peasy, and should last me a couple of decades based on my usage.

I'm not normally a safety nut, but when handling refrigerants, wearing safety glasses and some gloves would be prudent IMHO. That stuff will freeze burn your skin and occasionally some oil sprays out at me from the BMW. The FJ60 isn't as mean about it when I disconnect the hoses.

I don't have personal experience with the R12 substitutes, but as long as their not flammable, that might be a viable alternative. In the early R12 retrofit days, some folks experimented with mixtures of various hydrocarbons, like say propane or butane for example. Their refrigerant qualities are not bad, but the tendency to explode is no bueno.

 

[krs2fur]

First off, be VERY careful with R12 "substitutes" or NEW cans (import) being sold on Ebay. I've heard that some of these can contain any number of mixtures of chemicals that may get your AC cool, INITIALLY; but end up COMPLETELY frying your entire system.

That being said, I too have a 91 with the frozen gold (R12) flowing through her AC veins; so I speak from a place of ACTUAL personal research and experience.

In addition to carrying the "world destroying", "environmentally toxic" cooling agent in my AC system, I have the pleasure of residing in the wonderful land of "we know better than you and will regulate your DIY ass right into poverty" (also known as California. So, a couple of Summers ago, when I began to experience AC issues, I hit it with a quick charge of Craigslist R12. When it took a crap again a few weeks later, I looked into getting a local AC shop to give it a once over & figure out what was going on. Now, I grew up with an ASE Master Tech for a Dad and even had my own EPA certification for auto AC, at one time; so I AM capable of working on it myself, but getting your hands on actual R12 can be quite difficult and expensive here.

Anyway, after chatting with local AC guy, he gives me this schpeale about the 80 not having "barrier hoses" and the refrigerant leaching THROUGH the rubber hoses. Then proceeds to quote me for nrw hoses, replacing the O-rings, & recharging the system - $1800 (EIGHTEEN frickin' HUNDRED dollars!!!)

To be continued... So, after Mud ERASED the 4 or 5 more paragraphs that I typed up, I became too frustrated to type it all up again. At least for now. Here's the summary.

- replaced High & Low Schrader valves & recharged. Held for the rest of the Summer & into the next.

- Replaced all the o-rings (kit from Oreilly's ~$15) & recharged. Cold for about 3 weeks.

- Added a UV tracer dye (most auto parts stores have this). Pull the Schrader valves again & squirt it in using a small syringe. This will make finding leaks MUCH easier; it glows under a black light. I ordered a UV LED flashlight from T-Mart (China) for less than $10.

- Replaced expansion valve & cleaned the evaporator core. Recharged. Cold for about a week.

- Checked for leak location with black light. Remember that UV dye I mentioned, well it just paid off BIG TIME!! Leaking from top plate on compressor (where the High side & Low side fittings are). Found it had blown out the o-ring seal.

- Remember that O'Reilly's o-ring kit? Well it includes this o-ring seal; so I already had the part, just had to pull it apart (steam cleaned the compressor off first). Replaced the o-ring gasket on the compressor, vacuumed the system down (Harbor Freight pneumatic vacuum pump ~$15), recharged.

- SUPER COLD AC!!!!

I did learn, along the way, that if your 80 has ANY engine cooling issues, the AC will let you know (by not getting cold) AND will amplify the issue (causing it to heat up even faster)

If you're having trouble with your AC AND the 80 seems to be running warmer than normal, I'd look at the cooling system FIRST.

Possible cooling system culprits -

-Bad/inefficient fan clutch

-Low on coolant (Surprisingly this has been an issue more than once. I think my aluminum radiator may allow more expansion of the coolant than the small overflow bottle can regularly support

-Plugged radiator (Mine had so much rust & scale built up I was surprised it cooled at all)

 

[Rwhat]

They sell a R12 adapter for the manifold hose. You can still buy R12. Look on CL.

 

[Lumpskie]

First off, be VERY careful with R12 "substitutes" or NEW cans (import) being sold on Ebay. I've heard that some of these can contain any number of mixtures of chemicals that may get your AC cool, INITIALLY; but end up COMPLETELY frying your entire system.

That being said, I too have a 91 with the frozen gold (R12) flowing through her AC veins; so I speak from a place of ACTUAL personal research and experience.

In addition to carrying the "world destroying", "environmentally toxic" cooling agent in my AC system, I have the pleasure of residing in the wonderful land of "we know better than you and will regulate your DIY ass right into poverty" (also known as California. So, a couple of Summers ago, when I began to experience AC issues, I hit it with a quick charge of Craigslist R12. When it took a crap again a few weeks later, I looked into getting a local AC shop to give it a once over & figure out what was going on. Now, I grew up with an ASE Master Tech for a Dad and even had my own EPA certification for auto AC, at one time; so I AM capable of working on it myself, but getting your hands on actual R12 can be quite difficult and expensive here.

Anyway, after chatting with local AC guy, he gives me this schpeale about the 80 not having "barrier hoses" and the refrigerant leaching THROUGH the rubber hoses. Then proceeds to quote me for nrw hoses, replacing the O-rings, & recharging the system - $1800 (EIGHTEEN frickin' HUNDRED dollars!!!)

To be continued...

$1800!?!? To replace hoses and recharge? That's crazy, a local shop converted me over to 134 for $200.

 

[krs2fur]

$1800!?!? To replace hoses and recharge? That's crazy, a local shop converted me over to 134 for $200.

And how does it cool? My research came up with plenty of "Don't do it" for the 80. Most said that the system is already at it's limit with R12 & 134A isn't NEARLY as effective.

BTW, mine is now FREEZING COLD; even in 100°+ temps. I did fix it WITH R12 (on my own). So cold, in fact, that I often have to shut down the AC when driving long distances, because my hands cramp on the steering wheel.

After Mud erased the 4 or 5 more paragraphs I typed last night, I was too tired to retype it all; hence the "TO BE CONTINUED"

 

[Lumpskie]

And how does it cool? My research came up with plenty of "Don't do it" for the 80. Most said that the system is already at it's limit with R12 & 134A isn't NEARLY as effective.

BTW, mine is now FREEZING COLD; even in 100°+ temps. I did fix it WITH R12 (on my own). So cold, in fact, that I often have to shut down the AC when driving long distances, because my hands cramp on the steering wheel.

After Mud erased the 4 or 5 more paragraphs I typed last night, I was too tired to retype it all; hence the "TO BE CONTINUED"

In all honesty, mine might not be as cold as yours. I have had to take the direct cold air off my hands and face but I've never shut the AC off all together. That being said, it works better than the stock AC in my Evo and seems about as cold as the R12 in my Grand Wagoneer. With the heat and humidity out here, starting it on a hot day will yield cool air until you get moving. Once that happens thought, it blows pretty cold!

 

[ZackR]

My R134 system with the original evaporator (freshly cleaned) and original condenser (some dents but in decent shape) is enough to freeze me out on the highway. I turn the vents away from me to cool the rest of the interior.

Ambient temp in the low 90's with low humidity.

 

[krs2fur]

A little trick I've come up with for cooling her down after she's been baking in the sun all day - pop the sunroof open 2-3 inches when you first start it up, then crank the AC to the max. This pushes all the hot air up & out through the sunroof (heat rises). Then it's much more comfortable in just a matter of a minute or two.