AboutDavid Hill Expertise I can answer questions concerning automotive air conditioning systems, residential air conditioning systems and electrical repair questions.
Experience I have 16 years of experience in the automotive air conditioning arena and am currently an instructor for H.V.A.C.
Education/Credentials I am certified through as a universal technician under sections 608 and 609 of the C.A.A.
Expert: David Hill Date: 6/26/2008 Subject: 92 gmc suburban
Question Our a/c went out last summer, found tubing going to a/c box in back had rusted off, leaked out freon, I want to convert to a front only a/c to save any extensive repair
Answer Robert,
Wow, I have never heard of a/c tubing rusting through.
I can understand you wanting to save money by not replacing the parts, but I would recommend against it. Simply because your entire system was designed with the intent to run 2 evaporators. Cutting down the system to one may develop problems later on. Have you priced the replacement parts?
But if you are dead set on doing it... it is relatively easy. First you need to identify all of the lines that rusted through. Trace them to their source. On the high side, they will split somewhere after the condensor (in front of radiator) or after the receiver if your truck has one. The receiver is typically a black canister with 2 lines coming out of it. The lines have fittings connecting them to the receiver. Don't confuse this with the accuulator. The receiver will also often have a sight glass mounted on the top of it. The line leading to the rear will need to be sealed off completely. Then on the low side do the same thing. Your lines should join somewhere prior to your accumulator (a silver canister with 2 hard lines coming from the top of it) Again the line coming from the rear will need to be sealed completely. That completely eliminates the rear evaporator.
Now something to take into consideration... being that your vehicle is a 92, does it have R12 in it still, or has it been converted to R134a? If it is still R12, the recharge is going to be pricey regardless, simjply because of the rising cost of R12. You may want to consider looking into a conversion kit now.
After those two lines are sealed off, it is merely a matter of replacing your filter/drier and pulling a vaccuum on the system. Being that it has been open to the environment for such a long period of time, I would recommend leaving the vaccuum pump pulling on it for an hour or so, if not longer. That will ensure all the moisture that has built up inside the lines has been removed. From there, it is as easy as charging it back up. The only catch is that you would have to finish charging it by pressures, rather than looking at the sticker and putting it back in by weight. You will, after all have a much smaller system, so it will not hold what it originally held.
Again, I would recommend not making this change. Everything in the system was taken into account when it was designed and put together. But like I said, it can be done easily enough.
Good luck, and I hope that I was able to help out a little bit.
