kyshooter

I have 94 4runner and the A/C does not seem up to par. I ran the A/C at max and opened all the vents. I checked the sight glass and it is clear before starting the A/C but turns to white (which i figure is bubbles). When i turn off the A/C the sight glass goes to clear after a couple of seconds. From what I read this indicates that the R-134 is low. I was going to go buy a recharge bottle with a guage but i don't want to overcharge the system. I was think of getting a high side low side guage kit to check the system preasure and make sure it is low. I have never change R-134 or for that matter R-12 before. I found the High Side and Low Side conections. Just don't know what to do.

Kiroshu

The "white bubbles" in the sight glass indicates "Low Refigerant"

If it is an R134 system which i believe that truck is judging by the year.

If you want to do the "home style" mechanic way then by a can of refigerant and re-charge it. Toyotas are nice because they provide that nice sight glass unlike other auto manufactuers..... Anyway. All you have to do is re-charge it until the sight glass goes clear. Instructions are on most re-charge kits but its easy mode. Just turn the truck on and turn on max A/C and charge it into the "low" side. Keep letting it pull refigerant until the sight glass goes clear. Theres usually a gauge on the re-charge kit. And just follow the instuctions. You don't want to put too much refrigerant in there at one time soo theres a gauge to help you regulate how much you put in. Generaly just keep it about the middle. <--- As simple as i could have told ya. A/C is not my big area of exp but i hope this helps.

kyshooter

I got a r-134 recharge gauge and checked the psi. It was sitting around 10psi for a couple of min. I got some r-134 and charged the system up to 35psi with the outside temp 80 degrees. When i start the A/c on max it jumps to 48-53psi and then moves down to 30psi after that. does this sound normal or is the 48-53psi at the start to high

UKMyers

Bumping this thread. My AC quit working on my 94 Runner also. I suspect that it's just low on pressure. The green light comes on and everything but the compressor will not engage...no idle up or anything. This sounds a little bit more complicated than I initially thought. Is there anyone else that's done this before that wants to explain it?

UKMyers

Can anyone confirm if a 94 Runner is R-12 or R-134? Tech says it's on a sticker under the hood but can't check till I get home. Trying to get my AC working so I can take my wife and baby wheeling with me. Wife says NO AC.. NO Wheeling!! This is bad folks!

Local shop charges $189 for an R-134 recharge and $120 more for an R-12. Would sure be nice if I can pick up a kit from Autozone and do it myself.. considering that is what is wrong. Still need to check the level and the fuse and go from there.

UKMyers

Found this after an exhaustive google search on a page that discussed the changes that the Runners had from 90-95.

10.Other
All passenger seats (except the center) have an ALR (Automatic Locking Retractor) function in their 3–point ELR (Emergency Locking Retractor). The daytime running light system only operates the low–beam headlights. A new air conditioning system which uses R134a refrigerant has been adopted in the 4Runner only.



Looks like my 94 should have R-134

kwando

i recharge mine with R134

UKMyers

Kwando care to walk me through the recharge process? I located the high and low filler ports today. This is what the window looks like on the component that that the FSM tells you to check for freon level. I don't have anything to compare it to. Can someone confirm or deny that mine is low?





I found this under the hood confirming that mine is R134A

Windsor

FSM for mine listed a lot of A/C details, but basically..

For those with dual-gauge manifold:

• Hook up gauge manifold
• Hook refrigerant bottle to manifold, keep bottle upright!
• kick on AC
• run engine up to 2000 rpm
• check pressures
• open refrigerant bottle
• crack open "low" side valve
• stop flow periodically to verify pressures
• check window in dryer

For those of you without (just a can-and-a-hose), you're going to just add a can at a time until you don't see any more bubbles...

• Close valve on can tap
• Attach can tap to can (usually pierces can in side or top)
• attach hose to low pressure side of compressor (keep can upright!)
• kick on AC
• run engine up to 2000 rpm
• open valve on can tap
• let it drain for a couple of minutes, close valve
• disconnect hose from compressor

Important safety considerations to obey at all times...

Never connect a single-can to the high pressure side, you could burst the can.
Never tip the can to flow liquid refrigerant into the a/c system, this will munch the pistons in the compressor.
Never crack open the high-pressure valve (gauge manifold) while the a/c system is running. Best case is that you back-flow used refrigerant into your bottle, tainting your supply.

FYI, flowing liquid refrigerant into the a/c system is only done with the system nonoperational (usually initial charge after evacuation where you are dumping in a known number of pounds of refrigerant). If you are "adding to", there's rarely any reason to turn the can/bottle upside down to flow liquid (and it's dangerous, see above).

The "observe air bubbles" should only be done at 2000rpm. At idle, you might see some, which is normal. If you charge-until-air-bubbles-stop at idle, you'll most likely overcharge your system.

To determine what is the low-side and high-side of your compressor, chase the hoses. The low-side typically comes from the firewall (evaporator, "cool" coils) and the high-side typically heads off to the nose of the truck (dryer and condensor, "hot" coils).

One last tip, a slightly undercharged system will "cool much better" than a properly charged system. What's happening is that your evaporator is trying to freeze and usually it will ice up the condensation on it. While it sounds like a good time, an iced evaporator eventually ceases to flow air through and you get zero cooling effect.

This is also a good indication that you are losing refrigerant -- "well, it was cooling really well, you could see frost coming out of the vent!... and then within a week or two it stopped cooling." A very slight loss of coolant can do that, since there's the tipping point at which things go from "overworking" to "not at all".

HTH.

UKMyers

Where will one see these bubbles? Will they appear in the little window that I posted pics of?

TORTIS

iTrader: (1)

ACKits.com is a great site. Your system holds 25oz. I think your best bet is to drain the system, pull a good 30 minute vacuum on it, this way you can check for leaks, and if no leaks, put 24oz. in the low side, and call it a day.

ACKits has a great forum, a great product, and you will not get beat up, for asking the same old question.

The sight glass you posted a pic of is where the bubbles show up and when it gets clear you are almost there, and sometimes you may not get a clear site glass.. this is where you gauges come in to play


Hell, fly me up there and give mea place to stay for a week, and I will have you blowing snow out of your vents.

Windsor

Yeah, ACKits.com is a pretty good site.

UKMyers

Bit the bullet and took it to a shop... $89 and a pound of freon and it's blowing snow again...hopefully it lasts another 16 years.