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Freon in High or Low pressure valve(fitting)?

07-16-2004, 01:49 AM
BrianR. had posted the following:
Engine off. Attach the refrigerant can to the high pressure connection (driver's side of radiator near top of radiator). Turn can upside down and open valve to fill liquid into connection. Shake the can periodically to help fill and feel when empty. Close valve and exchange cans when 1st can is empty. Total capacity is 800-900 g (28-32 oz).

Close valve so that you are not adding freon and run engine at idle with a/c on and max cooling. Check sight glass just below the high pressure connection. You need to add more freon if you see bubbles unless the temperature outside is quite hot. Then, if cooling is adequate, leave it alone. If normally hot outside, add freon with engine off until you don't see any bubbles with the engine running. Put cap back on high pressure connection.

Don't run engine when filling system with liquid freon (can upside down) in high-pressure fitting.

I had used up the freon on my other car so I took the camry to the shop for freon add and leak check.
Leak check was neg. and the mechanic added the freon in the low pressure valve with engine running, can right side up, and A/C on max and running(he even gave it a little gas to get the process to go faster).

Needless to say, he looked at me funny when I told him about the hi pressure fitting freon add. I just didn' want to argue about it so I'm asking everyone which is better/safer/faster?


Brian R.
07-16-2004, 08:47 AM
The low pressure fill is safer, but Toyota fills in the high pressure side - faster. Neither is better, both accomplish the same thing.

07-16-2004, 08:59 AM
I use the LOW side but put the can in a bowl of water & also run a box fan on the raditor if its hot outside... seems to take the freon faster.... Bob

Brian R.
07-16-2004, 10:37 AM
Be careful how hot you get the can. It will explode if you get it hot enough.

07-16-2004, 02:18 PM
When I did mine, I used the low pressure side with the engine running. Worked fine. The refrigerant I used had compressor lubicant in it. Bought at K-Mart.

07-18-2004, 01:07 AM
By the way, Brian, I just wanted to thank you for your insight and advice on the distributor for my 93 camry. I finally found the right part on ebay of all places and got the car running.
Keep up the good work and yes I now have a Brian R. folder on my HD which includes all your procedures and ideas on Toyota repair.

Thanks again,
Keep up the good work.

Brian R.
07-18-2004, 03:16 AM
You're welcome. I try to fix more stuff than I destroy... :)

07-18-2004, 07:42 AM
I tried to retrofit from 12a to 134a , since 12a is banned. I got the low pressure valve to put in, it is gushing freon, any suggestions ?

07-18-2004, 07:50 AM
Also the recharging kit, the hose is without gauge
how much to fill in ?

Brian R.
07-18-2004, 01:42 PM
What did you do to convert to the new refrigerant?

07-19-2004, 09:24 AM
in 2001 toyota dealer replace 12 a with 134a.

Brian R.
07-19-2004, 11:19 AM
Turn on the A/C high and blower high. If not really hot outside, add freon until the sight glass is clear with no bubbles. Add freon gas (can upright) to the low-pressure side.

07-19-2004, 11:27 AM

question is the retrofit kit converting fromk 12a to
134a valve cannot be install in easily, think of
it as you fill air to the tyre, the nipple set up is
the same type, when I try to screw in the valve
on low pressure, freon keeps oozing out. No way
to install the new valve.

Brian R.
07-19-2004, 12:52 PM
Since it is difficult for me to understand the problem, I suggest you bring the car back to whoever installed the conversion kit and ask them to explain it.

07-19-2004, 12:58 PM
conversion kit has not been installed by dealer in
aug 2001, they would not make lifeeasy for me.
I am trying to install myself the retrofit kit.

Brian R.
07-20-2004, 09:46 PM
Sounds like the valve is leaking. See if you can find a way to tighten it, like a tire valve stem. If not, bring it back and get one that doesn't leak. (of course, I may not have a clue as to what's wrong here)

07-21-2004, 08:54 PM
Sounds like a problem with the valve adaptor. It should not make the freon come out. They screw right on with no problem on the Toyotas I have done. Mine came from WalMart but really only one company makes these kits and they made these parts since the days of R-12.

Should be as simple as screwing it on running the AC on high pop the can on upside down on the low side and go to 25-45 pounds. Buy the cheap gauge its only about 15 dollars. The sight glass may or may not clear in a conversion. Less 134 is used than R-12 so don't overfill. Cans and kits usually have very good directions. I have been very pleased with the 134.
As a note. It is illegal to mix the freons due to reclamation issues, but they do mix fine from a technical point. Don't mix if you are ever going to bring it in for AC service. That would contaminate their refrigerant.

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