I've replaced every component of the ac system except the evaporator, because research shows I need to pull the dash to get to it. The original system the clutch was starting to make noise and there was a system leak. Rather than try to chase it down, I just replaced everything, sans evaporator. I flushed the evaporator and used a tornado air chuck with a compressor to clean it out. Seemed fine, so I bolted the hoses, accumulator, condenser, and compressor in place, adding oil to all the components and some uv dye. I vacuumed down the system with manifold gauges and and a vacuum pump. It held a vacuum overnight, so I added freon the next day. It would not take freon on the low side even after waiting nearly an hour. I jumped the low pressure switch and the compressor kicked on, low side pressure did not drop and no freon was pulled. I read that the high side may need a boost if it's not reading any pressure at all. Closed the low side and opened the high side. It took immediately and once it hit 50psi, the compressor kicked on. I closed the high side and opened the low side and waited. Still wouldn't take anything even with the compressor kicking on, and while the compressor was on the low side stayed pegged on whatever psi it was at, usually 70-80psi. I vacuumed the system down, and again it held without leaking. I pulled the quick disconnect on the high side where it meets the evaporator and was met with a gush of uv dye, oil, and I assume liquid freon. I disconnected the low side that runs between the accumulator and the evaporator, then put the air chuck to the smaller high side port hoping to blow out whatever might be the problem. That got me a face full of fluid. One shower later I again put the air chuck with something in front of the ports so it wouldn't soak me again. I used some more ac flush and the air chuck, it blows through, but doesn't seem like I'm getting the full force. I hooked it all back up, vacuumed and tried to charge, same result. I'm led to believe that there is some sort of blockage inside the evaporator. Since I've literally replaced every other component, it seems to me that the evaporator is the logical cause. Any suggestions before I tear out the dash?
I am by no means an expert on automotive AC, this is just what knowledge I have. Possible when the compressor went out, pieces of debris went through and lodged in the evaporator. More than likely the receiver drier is clogged as this is where the desiccant filter medium is located and this part wasn't mentioned in the list of parts you replaced. The reciever drier should be replaced any time the AC system is opened. Without immediately pulling a vacuum on a newly installed one as ambient humidity in the atmosphere can cause the desiccant bag silica to absorb water beyond its efficiency in system operation. All parts should be final fitted and vacuum pump attached with the reciever drier installed last and vacuum pump running to minimise receiver drier's time of exposure to outside air. Also check / clean the temp controlling orifice tube screen or just replace it, cost is only couple $. Run a pressure test on the evap only to check flow output before tearing out the dash. Sent from my SM-G930P using Tapatalk
I've replaced the accumulator (what you're calling the receiver/drier) and orifice tube, twice. I did fail to mention the orifice tube, but ya, everything except the evaporator was replaced, even the high and low side pressure switches. Sent from my SM-G935V using Tapatalk
I have a compression tester like you use on engine cylinders, would that be something I could make work with this? I'm unsure how to measure the pressure. I get putting the air chuck to one side, just don't know what to use to measure the output. Sent from my SM-G935V using Tapatalk
On your compressed air, turn the regulator down to 10 psi and blow up a latex balloon with just the end of the chuck. Time how many seconds it takes till it bursts. Next take the same type balloon and attach it to the output of the evap and fill it with the same 10 psi from your chuck from the other side. See if the time to bust is similar. If it takes longer, there is an obstruction in the evap. Sent from my SM-G930P using Tapatalk
From your earlier description of getting covered in flush, there should be a big difference in air not moving through the evap. @aeidian1 Sent from my SM-G930P using Tapatalk
Further testing revealed a definite decrease in flow through the evaporator, so I ordered another and tore the dash down. Installed the new evaporator and discovered that the low side of my manifold gauges was bad and not allow refrigerant in. It would read the pressure, but it wasn't allowing anything through or decreasing when the compressor kicked on. The gauges came form Advance Auto Parts, and I've done successful repairs in the past with them. I intentionally didn't buy from harbor freight when I got these because of all the negative talk about their set, but I tossed these in the trash and picked up a set from harbor freight THIS time and I was in business. I've got the system charged to the correct weight and the pressures are within range. Two problems are left, one, the system defaults to defrost with on max ac, and only on max ac, under engine load. I smoke tested vacuum lines and haven't found a leak, some say pulling the battery box and checking under it is usually the culprit but I haven't gotten that far. I couldn't tell you if this issue was represent before I overhauled the ac system. Two, my auto headlight system doesn't seem to be working, so I may have forgotten to hook something back up when I put the dash together. The headlights work manually. Sent from my SM-G935V using Tapatalk
Sorry about your faulty gauges. Definitely a vacuum problem causing the default to defrost. Hopefully after these two problems are cured it is all done.
Pulled the battery box and inspected there, no visible cracks. Put the smoke machine on it, and there's smoke coming out of the top of one of the 4wd lock solenoids. There's two of them and they look identical. I swapped them and put the smoke back on, it didn't come out the top of that one, so I assume the other is bad then? Comes out from under the top cap in the pic. Sent from my SM-G935V using Tapatalk
