I switched from the R-12 to the R-134 A freon, when we drained the R-12 the system was sealed and operated however it was not cooling. The Freon was after all over 17 years old. Now the system cools nicely however a noise that was not their before that sounds like a high speed rattle, and is louder as the rpm climbs.

Also I replaced the speed sensor on the tranny, the speedometer works as does the cruise now, however the odometer and trip meter are both not working.

After I replaced the speed sensor now the overdrive kicks in and out at speeds above 30 mph, any ideas?

 

Just changing the freon from R12 to R134a isn't doable. The seals and pressure switches and some other components in the compressor need to be R134a compatable vs. being only R12. In time, the AC system will die on you this summer. It will die even if you don't use it since the R134a is already attaching the older R12 seals in the cooling loop.

 

This is wild I did not do the work myself, I took it to a shop so you can imagine what my thoughts are, now I know why they only offer a 30 day warrenty. Ok so what needs to be done to make this work correctly?

Thanks

 

First, I would ask the shop what components were replaced to ensure the proper use of R134a in the vehicles AC system. Usually a retro kit is needed. See the first link for the cost break down of the reqiured components.

Rather than type a long page of information, check out this link for the Chrysler retro kits ...
http://www.teamchicago.com/imperial/imp-ac.htm

In some of the Chrysler vehicles that use a certain Nippon-Denso compressor, it's dangerous to use R134a in the system since the pressures are way too high.

The Imperial vehicles use the larger engines like our vans and are very similar for some of the AC components. Thus the FR-12 (FRIGIC) could be an option for you.

"... If you are a Do-It-Yourself AC mechanic, there are many substitute refrigerants for your car, some of them are dangerous, but still legal. You can browse all the stories about these refrigerants on the Web, you can legally create your own refrigerant and use it, but I think there is a better way.
Read the April 97 issue of MOTOR Magazine, it will distill the topic down to a reasonable decision for you to make. For example, if you own a 79, or later, Chrysler with the Nippondenso C-171 compressor, you'll learn that with R-134a you'll need to replace that compressor; also, they list seven or eight others that won't tolerate the higher pressures that R-134a imposes on the system. The older V-2 may not work either, the front shaft seals aren't designed for the higher pressures of R-134a.
There is one, new refrigerant that is EPA approved and available called FR-12, also FRIGIC - concocted by Intermagnetics General Corp and now nationally distributed by Pennzoil, out of Houston. The changes you would need to make are minimal, the cost is much less than R-12, and, most important, the physical and chemical properties are quite close to the R-12 unit you already have.
There'll be no high pressure seal blow-outs, the hoses and fittings and O-Rings are compatible. Many bad stories are circulating about this refrigerant because it does not offer a large profit job for the trade mechanics - it simply doesn't take a pile of money to make your car cool again. If your hoses or expansion valve are leaking, if the compressor is noisy, then no kind of refrig is going to cure those problems, fix them also.
You can call 1-800-555-1442, Intercool Corp., and get an idea of where you might take you car in your location. This subject is rapidly turning into a gigantic mess, read the magazine before you commit to any retrofit.
..." - http://www.imperialclub.com/Repair/Air/refit.htm (more there too!)

The AllPar site has some good advice too. It's worth the read.
http://www.allpar.com/eek/ac.html

 

I got to the shop and lo and behold saw the actual mechanic that kept telling me that it was no longer under warrenty, Now all I ask was what new parts he used, after stuttering and stammering he finally admitted that NO new parts were used. So that means I might as well face the fact that everything will probably have to be changed. Oh joy. Well I did learn that not just everyone has the answers and to check many times before getting work done. Thanks Steve. BTW any ideas on the other dilemas I have. Odometer and trip meter and the OD kicking in and out?

 

The Odometer and tripmeter on these dodges have a little 16 tooth and 26 tooth gear deep in the speedo cluster. I found the combo for$27.60 delivered to front door.With a little patience, about two hour job.