My Custom 1980 W116 300SD Project Part 2 - PeachParts Mercedes-Benz Forum

Squiggle Dog · #10 09-21-2018, 11:49 PM

The air conditioning has been working well, but it's been leaking. I noticed a slight amount of oil at where the receiver drier connects to the pipe right after having the system charged, but thought it was just residual oil from when I lubricated the threads. I figured the air conditioning shop would have caught it if it was a leak.

After I got back from Utah, I noticed oil was dripping off the bottom of the car. I thought it was an oil cooler leak, but I traced it up to the fitting on the drier and could hear the refrigerant leaking out.

In order to tighten up the fitting, I had to loosen up the hose above it just enough to rotate it out of the way without the refrigerant leaking out. Then I unbolted the condenser and used a crow's foot wrench to tighten and loosen the fitting several times before cranking it down very tight.

It's still leaking, but not as much and at least the air conditioning is still somewhat cool. I'm done with flare fittings. All they seem to do is leak. I'm going to have to redo this using O-ring fitting parts.

The receiver drier is in a really bad location when it comes to accessing the fittings. I was trying to make the parallel flow condenser upgrade look stock, but it's been too complicated. I'm probably going to use a drier from a newer W126 chassis Mercedes (which uses O-ring fittings) and mount it behind and under the headlight in the crook by the left horn.

With the drier out of the way, it will allow me to install a 2" wider condenser for even better air conditioning performance. I'll have to make new mounting brackets.

I'm really hoping that the expansion valve fittings (which are flare fittings) aren't leaking so I can get away with cutting the ends off the hoses under the hood and crimping new fittings on them without having to touch the expansion valve end in the cabin.

I was hoping someone made an evaporator core for the W107/W116 chassis that uses an o-ring style expansion valve, but it seems they don't exist. I could, in theory, have someone weld O-ring fitting ends on my evaporator, but it would require removing the climate control box again. I'm hoping a lot that the expansion valve connections aren't leaking so I don't have to mess with anything in the cabin.

In other news, I took the car to its annual emissions test and the employees there were flabbergasted to see a diesel-powered car and didn't know what to do with it, so they finally gave me a "Director's Certificate" which didn't cost any money. My roommate's 1991 W126 350SDL has been having a lot of issues, so he's been driving my car to work while I tinker around with his. I've also been selling quite a few parts from the 280SE parts car, including the engine and transmission.