Dash Air How Much Does an R-12 System Holds

[Richard and Rhonda]

The expansion valve is located where the hoses go into the evaporator ( the radiator like thing at the front of the coach where the fan blows across to produce cold air) If you look under the dash console you will find a big black box that all of the dash AC hoses come out of. Find where the high pressure freon hoses go into that black box. You will find the expansion valve there. You will see it connected to the high side AC hose. It is easily identified, it looks like it has a fifty cent piece stuck right in the middle of it.

Take it to an AC speciality shop to get a new one. Don't bother with a local auto parts store, they will try to cross ref against a make of car. IF you don't have any luck, let me know, you can ship it to me, I will take it to a huge AC place in Fort Worth that has a gazillion AC parts. Make sure you use new O rings when you put it back.

With the high side high, and the low side low, it does sound like a clogged expansion valve. Now you have to ask, what clogged it? The point is, something did, and your lines should be flushed prior to putting the system back together, or you are likely to repeat this exercise.

If you did refill with R-12, you need to go back to a specialist who will recover it. It is no longer made, and sells for over a 100 dollars a pound. Well that and a minor thing about a hole in the ozone layer.


Now, if you are going to the trouble to replace the expansion valve, you have to take the system down to do it. Invest a few extra minutes to use a valve compatible with 134a, change the oil in your compressor, and convert the system to 134a. If you are going to replace this valve, it does not make sense to ignore the conversion and refill it with r-12. You will easily save the cost of the conversion in the difference in cost between the gases. Make sure the shop you use gives you some credit for the R-12.