Automotive Air Conditioning Information Forum (Archives)

wepeterson47 on Mon June 04, 2012 9:33 PM

Year: 1989
Make: Toyota
Model: Truck
Engine Size: V6
Country of Origin: United States

I'm a consumer with 2 options for the AC on my newly inherited 1989 Toyota V6 Truck Motorhome AC. It looks like I've got the option of 2 shops - one to install R12 and the other to retrofit w/R134. My relatives hadn't had the AC working for a few years and after that it's been sitting for approx 5 years. No refrigerant is in the system now (tech giving me an estimate pushed on the shrader valve and nothing came out). Would it be better to have it repaired with R12 or R134? I have no idea what condition the other components may be in. Any advice or link to a post would be appreciated.

Thanks in advance, wep.

Dougflas on Tue June 05, 2012 7:49 AM

This is my opinion. If the system was originally designed for R12, keep it R12 especially a motorhome. I also base this on the fact that I have 100 lbs plus of R12. I would make sure of the condition of the hoses and replace them if needed which they probably need to be replaced. Install a new drier and probably a new compressor as this vehicle is 23yrs old. If it has been empty , possibly a new TXV after a flush of evap and condenser.

wepeterson47 on Tue June 05, 2012 8:20 AM

Thanks.

wep

NickD on Tue June 05, 2012 8:51 AM

Nothing wrong with R-134a either, if you can find compatible parts from a 94 or newer Toyota. Would base the decision on the condition of your 89 parts. A parallel flow condenser is a must plus all R-134 compatible components.

You can save a huge fortune if you do all the work yourself. Is this a class C on a conventional Toyota chassis? That makes it much easier.

chris142 on Wed June 06, 2012 11:32 PM

I'd retrofit it over to R134a if it was mine. Those Toyota trucks work well on R134a and I've never had to change the condenser on one when retrofitting one. HINT:The 4runner of the same vintage used a doulble condenser! They have one in front of the other and those work great on R134a!

I would flush out the mineral oil, Change all the seals, replace any bad hoses, new dryer, add about 7 oz of Ester oil and charge it with R134a. Make sure that the heater control valve is sealing the hot water off from the heater core. If that valve is leaking you wont ever get cold air.

NickD on Thu June 07, 2012 9:01 AM

But then the 88 Toyota Supra Turbo with a good engine driven fan clutch and two axillary electric fans is terrible with an R-134a conversion. Only uses 24 ounces of R-12 so not even worth the effort.

Still have no idea what vehicle this is, assuming a cab over pickup truck Class C motorhome. Then you also have a lot more volume to cool with these things. So what kind of AC system is in a regular cab pickup? Is it stock or did the RV company modify it?