I thought I would just share this afternoon's experience replacing my oil coolier line. I read the archives on this topic, and most said you had to remove the motor mount, although a couple people said you didn't have to. This was my experience replacing the line that connects to the bottom of the cooler, although the process would be the same for replacing the top line:

1) get everything loose - oil cooler-to-radiator brackets, a/c compressor (this step is key), both oil lines at oil filter housing, the two brackets that hold the lines in place

2) pull the bottom of the oil cooler out a couple inches so you have some space to work. Put some wrenches on there and see if the nut will come loose. Do this step first, because if you can't get that nut loose, you might as well stop now.

3) Open the lid on the filter housing and drain the engine oil

4) completely unscrew the line at the oil cooler. Have a drain pan ready because this gets messy. I would estimate at least another 1/2 quart of oil drained out of the cooler as I took the line of.

5) completely unscrew both lines at the filter housing and pull them out of the housing. You need to undo both lines so you have room to move the lines around and pull them out. Its a very tight fit.

6) This is the fun (read, frustrating) part: pull the pipe off the bracket that attaches to the block and push it down and back (just a couple inches). Then grab the end of the line with the rubber and fish that end up so that the end of the hose with the nut on it is in your left hand. Then continue bending the rubber line back until it touches the metal part of the same line (you are basically bending the rubber part of the hose 270 degrees back onto itself). Now fish the folded up part of the line under the wiring harness and up between the power steering pump and airconditioning hose. This part is why it is important to loosen the compressor, run its tensioner all the way loose, and push the compressor down. If you don't do this step, there won't be room to maneuver the hose in between the power steering pump and airconditioning hose and brackets.

7) Now just gently wiggle and tug at the line directly towards your body until, moving it around for clearance, and it will come out!

8) As the manuals say, installation is the same as removal!!

Anyway, I hope this helps. It was kind of tough figuring this out on my own, but hopefully no one else will have to go through this now that I wrote it out for everyone.

Greg
'84 300D
163k