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LowSL2
07-20-2007, 05:55 PM
I finally got around to getting the A/C in the R/T working yesterday. I flushed everything out, replaced the filter/drier, gaskets, O-rings. Evacuated for about 45 minutes to get all the crap out of there. Held vacuum for 30 minutes just fine. Added three cans of R-134a as well as 8.25oz of oil. Works great.

The only issue is the high side gauge jumps around between 210 and 270. It's not constant like other A/C systems I've worked on. Is this normal for the TIII A/C system? If not, has anyone encountered the problem before?

What's interesting is the FSM says the high side should be between 210 and 270 when it's 90º ambient. And that's the amount the gauge is jumping around.

Other than the weird gauge reading, it gets cold. Really cold. :)

turbovanman²
07-20-2007, 07:15 PM
270 seems a bit high but if the system is cycling, then the high side will change lower and higher. How many lbs/oz's is 3 cans worth, you could have over charged it.

ShelbyMotorsports
07-20-2007, 07:22 PM
Added three cans of R-134a as well as 8.25oz of oil.

Sounds like you overcharged the system as three cans is too much. Remember when going from r12 to r134a you are supposed to put in 10-15% LESS r134a.

Millerman340
07-20-2007, 09:22 PM
Also if you used the wrong oil viscosity it will keep building pressure , read normal , high, & cycle on and off. I did that when I changed mine over & used GM oil & should used mopar spec that's thinner.

MiniMopar
07-20-2007, 09:50 PM
+1, sounds like it is overcharged. If it is still a liquid when it gets to the compressor, it can make the pressure jump around. It's also bad for the comp. The pressures are just a reference to make sure things aren't totally out of whack and if it is an old compressor it is not going to perform like a new one. To do it exactly right, you are supposed to observe the quantity that you put in there. I just look at the window on the receiver/drier and stop adding when the bubbles go away.

LowSL2
07-21-2007, 05:36 AM
One can is 12oz. I put three cans, but I had some left over in one of them. I'd have to say it was half full. But the high side pressure was jumping around after the first can.

Here's a video of the high side gauge jumping around. It's a 3g2 file from my phone. You'll need realplayer or quicktime to view it.

http://home.comcast.net/~lowsl2/rt/ac.3g2

turbovanman²
07-21-2007, 12:28 PM
16 oz is a pound, so you roughly have 30 oz in your system, which is 1.875 lbs. I believe the factory fill is somewhere around 1.8-2.0 lbs so your a bit overcharged.

LowSL2
07-21-2007, 04:38 PM
I drained into an old propane tank, evac'd and refilled. I put about 24oz in. And the gauge is doing the same thing. I'm looking through the previous owners service records and it looks like he had problems with the A/C before. It was evac'd and refilled two times since 98.

Are there any rebuild kits for the R/T compressor? The only 16V compressor stuff I can find is the Masi one.

turbovanman²
07-21-2007, 05:00 PM
I drained into an old propane tank, evac'd and refilled. I put about 24oz in. And the gauge is doing the same thing. I'm looking through the previous owners service records and it looks like he had problems with the A/C before. It was evac'd and refilled two times since 98.

Are there any rebuild kits for the R/T compressor? The only 16V compressor stuff I can find is the Masi one.


I am sure there available somewhere, I might need one soon also.

MiniMopar
07-21-2007, 09:22 PM
I'd try swapping the H-valve next.