Freon substitute?
Post Fiend
Joined: Feb 2003
Posts: 6,940
Likes: 2
From: Eastern WA
Best solution is to convert to 134. This is a farily straightforward DIY process. Borrow a buddies vac pump and gauge set and buy a conversion kit. FWIW, you can top it off with 134 or 502 but if it ever goes to a shop for service and they detect anything other than 12 in there (yeah, they test) you're gonna hear about it. Money (yours) fixes what you will hear then tell you.
Rather Be Floatin
Joined: Oct 2005
Posts: 2,468
Likes: 0
From: Marble Falls, Tx.
I am currently using Freeze 12 and it has much better cooling power over converting to R-134a. The freeze 12 can be added to the existing charge or it can be used for a complete refill. I would buy a couple of extra freeze 12 cans and keep them in case of needing a "top off" because I dont know how much longer they will continue to sell it. I have not tried the HOT SHOT but I am very happy with the freeze.
Post Fiend
Joined: Feb 2003
Posts: 6,940
Likes: 2
From: Eastern WA
Using the correct refrigerant for a given application as well as a gauge set, you charge until the low side is in the correct operating range. High side is not normally needed unless you are diagnosing a problem although it's generally a good idea to look at it anytime a system is serviced.
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Post Fiend
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Postmaster
Joined: Aug 2004
Posts: 2,908
Likes: 2
From: West Mansfield, Ohio
On my 91, the "high side" is the shrader valve by the canister up around the heater box. The "Low part" is the shrader valve on the line coming from the condensor on the drivers side.
What I recently did with mine is I just converted it to R-134. All you need to do is change out the shrader valves, the O rings (can be the hardest part) and put the refridgerant in it.
I didn't have a vaccuum pump when I did mine. I hooked the can of 134 to the high side like usual, but when I opened it up, I went to the low side and stuck a nail into the valve to open it up, and let the air out as freon took its place. Once freon started to come out, I closed the valve. Then once it sucked that can down, I put another in it, and it blows at 39 degrees on a 75-80 degree day. Worked good ever since.
Oh by the way, my suggestion is to convert it to 134. If you do it right you'll have excellent A/C.
What I recently did with mine is I just converted it to R-134. All you need to do is change out the shrader valves, the O rings (can be the hardest part) and put the refridgerant in it.
I didn't have a vaccuum pump when I did mine. I hooked the can of 134 to the high side like usual, but when I opened it up, I went to the low side and stuck a nail into the valve to open it up, and let the air out as freon took its place. Once freon started to come out, I closed the valve. Then once it sucked that can down, I put another in it, and it blows at 39 degrees on a 75-80 degree day. Worked good ever since.
Oh by the way, my suggestion is to convert it to 134. If you do it right you'll have excellent A/C.
Post Fiend
Joined: Feb 2003
Posts: 6,940
Likes: 2
From: Eastern WA
Originally Posted by handyman43358
On my 91, the "high side" is the shrader valve by the canister up around the heater box. The "Low part" is the shrader valve on the line coming from the condensor on the drivers side.
The reason the system must be completely evacuated when it's opened for service is straightforward. Air does not condense and as such can do a few undesireable things. It will a) result in abnormally and wandering high side readings, possibly causing the relief valve to vent or a hose to blow, depending on the system (hope you're face or body is not in the way) and b) reduces system performance. Since air is incondensible, it can't be throttled and made to boil (phase change), such is one part of the process required for A/C to function.
Post Fiend
Joined: Jan 2003
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From: Connecticut
Rather Be Floatin
Joined: Oct 2005
Posts: 2,468
Likes: 0
From: Marble Falls, Tx.
I bought my freeze 12 at Napa. I could not buy it in the Houston, Tx city limits so I had to drive to an "unregulated" county to get it. And as cowboy said the low side intake is the one to charge system, and as he said if you are unfimiliar please have someone with experience evacuate and recharge the system for you.