Provident Engineering: What Else Can Go Wrong? The Sonata's A/C

Vehicle: 2005 Hyundai Sonata V6

Problem: A/C not working

It was going to be a simple diagnostic. Maybe replace an o-ring and do an evac and recharge. So I tested for leaks and found a small leak on the liquid line. Here's where the trouble began.

I looked on several online auto parts stores for this hose. Nobody had it. I called the dealer (I didn't have the VIN handy) and asked them if they had the part. They had to order it in for about $470. I asked them what the part number was and they gave it to me.

Cool. Now I can search online. As luck would have it, I found one on ebay for $160. Fast forward to opening the box and discovering it was completely wrong. As it turns out, there was a model change mid-year in 2005. Thanks Wikipedia!

Ok, back to the search engines. Since late 1998 to early 2005 were the same body style, I figured that the 2002 liquid line (part number 977683D001) would be correct. After all, it looked right . . . at first.

I missed the slight difference on one connector. When I pulled the old one off, I saw that they were different, as you can see here. Here's what was on the car:

2005 Hyundai Sonata Liquid Refrigerant Line Connector

And here's the one I got from ebay:

2005 Hyundai Sonata Liquid Refrigerant Line Connector, part 977683D001

Then I thought I had a brilliant idea. I'd cut off the other end of the old one and put a couple o-rings on it to adapt the ends. So here's the end I cut off that connected to the expansion valve:

This'll go between the two parts with a couple o-rings and seal it right up . . . maybe.

It fits in this end.

With a little machining, it'll fit in the other end too.

Just trimming some thickness off the sides.

Now it fits.

I found one o-ring that looked good, and one that was slightly small.

It didn't seal well. It was also not a good match. Also, the stud wasn't quite long enough for the thicker connector. So I came up with another idea.

I ground off the crimp connectors and pulled the entire metal ends out of the hoses and put the old connector on the new hose. The hoses used some sort of sealant between the hose and pipe, so I tried epoxy. It should hold up over time.

Three hose clamps, epoxy, and a new o-ring should keep the refrigerant inside.

We're not done with things going wrong yet. Houston, we have a problem. We're losing pressure. Some mechanics have those fancy refrigerant gas detectors. I use a low-tech, yet effective solution: soapy water. My soapy water wasn't showing any leaks on any of the hoses or hose connections. Yet I was hearing a hissing noise.

Some mechanics have fancy stethoscopes to find noises. I used a 3 foot length of 3/4" heater hose to find the hissing noise on the compressor. Oh, that should be easy. Just replace the o-ring on the end of the hose connector.

Just a little verification with the soapy water, and . . . not so fast. No bubbles.

I finally found the source of the leak.

At first I thought it was a crack in the compressor, but it was actually where the parts of the compressor body join together. I missed that leak the first time I checked for leaks.

New Compressor Installation

After a week, we got a compressor in the mail and I installed it. Installation was pretty straightforward. I had to remove the small shroud under the compressor and remove the oil filter and then it came out fairly easily. After installing the new one, I checked for leaks and it passed. I evacuated the system and left the vacuum pump on for an hour. Then I was using my new refrigerant scale to charge it and I had almost a full charge in, 0.62 kg, when the clutch shut off.

New Compressor Un-Installation

Wait, what? After some troubleshooting, I determined the clutch electromagnet had an open circuit. I had to recover the refrigerant and remove the new compressor and put the old one back in. I think GPD didn't install the new clutch correctly because it would wiggle back and forth. Plus, there was that burning smell.

Filter Drier

I'm not sure why it took me so long to find it. But the filter drier is built into the condenser on the driver's side. You remove the plug on the bottom with a 10mm Allen wrench. The filter is right above the plug. Here's what they look like. I used mass airflow cleaner to clean out the filter screen. Then I applied PAG oil to the threads and o-rings before re-installing it.

Here's what the old and new desiccant (moisture absorbent) bags look like. After seeing this, it's no wonder why they recommend you always change the filter drier (or desiccant bag or accumulator) when you replace the compressor. Not changing it would be like replacing an engine and re-using the old oil filter.

Finished?

After evacuating the system and recharging it, the thermometer says I did an adequate job. By the way, the new compressor was a Denso brand. It came with the proper manifolds so I didn't have to swap them from the old unit.

So I disconnected my hoses from the charging ports and found one more small problem I need to take care of . . . tomorrow, because there's a wind and rain storm coming in. The high side charging port valve is leaking slightly. Somehow I didn't find that when I did leak checks the first two times.

And my valve core tool wouldn't hold onto the valve core to pull it up, so I couldn't finish it before the rainstorm hit. I didn't know that it was the large size core. My tool only works for the smallest size valve cores. You can see in this picture that the valve core on top just doesn't fit through that small hole.