R12 to R134a Retrofit Question.

I bought the retro kit for 40 bucks. I know some of your probably dont agree with the kit but thats ok. I just have a question regarding the fittings. The fittings for the high and low side are on the back of the ocmpressor unit. They don't have the shrader valve, like a tire valve stem. They are threaded though. There is what appears to be a valve on the fitting that you could put a wrench on and turn. I turned it and it sounded like refrigerant coming out. (I know I know it's illegal .. lol) I just don't understand how I am supposed to screw these retro fittings on and recharge the system without opening and closing this valve at some point. Has anyone done this and maybe have the step involved? The paperwork with the kit make it sound like there are supposed to be shrader valves and the new fittings are set up that way as well. Thanks!

Oh yeah, it's a '94 Cherokee

no it doesnot valve the tire valve as you call it when you open the screw valve half way that how you put the freen in and close it when your done .the 134a will not get that cold if you can find some freeze 12 that works with the r12 and you don't need a lince to by it read the intruse go with the reto fit kix you sure take all the oil out of rhe compress for 134a and r12 do not mix you can by freeze 12 on ebay fairly chep and it does work beter

xj87 said:

no it doesnot valve the tire valve as you call it when you open the screw valve half way that how you put the freen in and close it when your done .the 134a will not get that cold if you can find some freeze 12 that works with the r12 and you don't need a lince to by it read the intruse go with the reto fit kix you sure take all the oil out of rhe compress for 134a and r12 do not mix you can by freeze 12 on ebay fairly chep and it does work beter

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What did he say? Oh, and werston your 94 should be R134a from the factory. IIRC that is right around the R12 no more date. I'm thinking 93.

94' is the split year - early =R-12, late = R-134A. To convert if it's the R-12 just evacuate the R-12 at any shop and ask them to pull a vacuum, then use your kit to put on the adapters and refill. When R-134a is mixed with R-12 oil it causes the oil to become very acidic and rot your system out. Using the kit there are addatives in it mixed with the R-134a to keep this from happeningand keep everything o.k. There is no need to change any components when doing this.
Erich

No matter how you do the conversion and I don't care what the instructions say you NEED to have the old system evacuated. What that means is they put a vacumn on it and draw the system down, 40mmhg sounds about right and it needs to stay at that vacumn for about an hour. This will remove any old refrigerant and more importantly any oils left over. It will also draw any moisture out of the silicate bag thats in the tower, or you can put a new tower in. At that point you can put the new valve adapters on and refill the system with R134a. It is also a good idea to have them stop drawing vac after the hour or so and let it sit still connected and watch the vac gauge on the machine. It should not move at all, if it moves and you loose vacumn you have a leak and that should be addressed before you refill it. Replacing the tower though is usually a good idea, there is a filter in there that removes dirt and crud, some towers you can replace the filter on once the system is empty but the tower replacement is quicker.
To put it in perspective, when you have a NEW a/c system installed by a good shop they normally hook that vac device up and leave it drawing for 8-12 hours, usually overnite, this removes any moisture that got in during the install of the components. Remember this is with NEW components that were sealed when the shop got them with plugs on all the lines and they were only open long enough to make the connections.

xj87 said:

no it doesnot valve the tire valve as you call it when you open the screw valve half way that how you put the freen in and close it when your done .the 134a will not get that cold if you can find some freeze 12 that works with the r12 and you don't need a lince to by it read the intruse go with the reto fit kix you sure take all the oil out of rhe compress for 134a and r12 do not mix you can by freeze 12 on ebay fairly chep and it does work beter

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There's this thing called English. I understand it helps to use it correctly when trying to communicate.