I could never get the engine A/C in my 1987 El Capitan to work right. It would cycle too much despite being charged, and didn't put out cold enough air. My solution? Take everything out except for the evaporator and start over.
This is the original ugly, inefficient R-12 system. I had previously installed the auxiliary fan.
First thing was to get the fan out of the way to get at the condenser and hoses.
All the essential parts are removed, time to get busy and install the new. I kept the OEM evaporator because it would have been next to impossible to remove it without replacing too many more parts. I flushed it out with a quart of A/C solvent instead. By keeping the evaporator I could not convert to R-134a without using adapters and risking a leak. Plus, R-134a is too difficult to charge correctly and get the right amount of oil in.
I bought the biggest R-134a parallel flow condenser that I could, which is much more efficient that the OEM serpentine tube style.
New R-12 compressor. This was a lot of fun to replace, I had to remove the left front tire and splash panel to gain access.
New condenser in place. While I was at it, I drilled out all of the radiator mount tack welds and replaced with bolts. Now if I ever have to pull the radiator I remove 6 bolts and it will drop right out. Before I would have had to remove the condenser to gain access, there was no way I ever wanted to do that again!
New filter/dryer and 2 of the new hoses.
New expansion valve. I cleaned everything up and insulated the suction line later on.
Pulling vacuum. At first it would not hold, and I discovered that one of the fittings at the expansion valve was not centered correctly. The rest of the fittings were R-134a with an o-ring, I could not do that with the expansion valve due to the evaporator connections. Afterward it held vacuum perfectly, the needle never moved after an hour.
Charging with the first can of R-12, it took 5 cans total. I had previously added 4 ounces of extra refrigerant oil and UV leak detector. The 150cc of oil in the compressor was not enough for the entire system, around 8 ounces total was recommended.
Everything is back together and working well. I can't imagine what an A/C shop would have charged me to do this! With a motorhome you had better be able to use tools or have a lot of money. I prefer using tools.
This is my first attempt to replace an entire A/C system in any vehicle. If I can do it so can you.
The engine is a Ford 460, which doesn't slow down at all with the A/C on.
Another big obstacle was getting the correct belt and installing it. Whoever owned the RV before I did installed the wrong type of belt (cog), and installed it in such a way that the belt would shred after just 2,000 miles. This is because the tensioner was installed wrong and bent the belt backward, rather than keeping the groove inward. I replace the tensioner bearing while I had it out, one less potential headache prevented for just $18. The engine has 4 belts, all are new and the correct ones.
This is the original ugly, inefficient R-12 system. I had previously installed the auxiliary fan.
First thing was to get the fan out of the way to get at the condenser and hoses.
All the essential parts are removed, time to get busy and install the new. I kept the OEM evaporator because it would have been next to impossible to remove it without replacing too many more parts. I flushed it out with a quart of A/C solvent instead. By keeping the evaporator I could not convert to R-134a without using adapters and risking a leak. Plus, R-134a is too difficult to charge correctly and get the right amount of oil in.
I bought the biggest R-134a parallel flow condenser that I could, which is much more efficient that the OEM serpentine tube style.
New R-12 compressor. This was a lot of fun to replace, I had to remove the left front tire and splash panel to gain access.
New condenser in place. While I was at it, I drilled out all of the radiator mount tack welds and replaced with bolts. Now if I ever have to pull the radiator I remove 6 bolts and it will drop right out. Before I would have had to remove the condenser to gain access, there was no way I ever wanted to do that again!
New filter/dryer and 2 of the new hoses.
New expansion valve. I cleaned everything up and insulated the suction line later on.
Pulling vacuum. At first it would not hold, and I discovered that one of the fittings at the expansion valve was not centered correctly. The rest of the fittings were R-134a with an o-ring, I could not do that with the expansion valve due to the evaporator connections. Afterward it held vacuum perfectly, the needle never moved after an hour.
Charging with the first can of R-12, it took 5 cans total. I had previously added 4 ounces of extra refrigerant oil and UV leak detector. The 150cc of oil in the compressor was not enough for the entire system, around 8 ounces total was recommended.
Everything is back together and working well. I can't imagine what an A/C shop would have charged me to do this! With a motorhome you had better be able to use tools or have a lot of money. I prefer using tools.
This is my first attempt to replace an entire A/C system in any vehicle. If I can do it so can you.
The engine is a Ford 460, which doesn't slow down at all with the A/C on.
Another big obstacle was getting the correct belt and installing it. Whoever owned the RV before I did installed the wrong type of belt (cog), and installed it in such a way that the belt would shred after just 2,000 miles. This is because the tensioner was installed wrong and bent the belt backward, rather than keeping the groove inward. I replace the tensioner bearing while I had it out, one less potential headache prevented for just $18. The engine has 4 belts, all are new and the correct ones.
