After a couple of hours of diligent searching, I was unable to find a how-to or any thread with actual part numbers and all that jazz on how to patch a leaky section of SLS hard line on the W123 300TD. This fix will work with pretty much any section of the hard line however, may not be applicable for sections running over the rear sub-frame.
I want to preface the following with an explanation of the verbiage used in this post as there are many different names for the fittings used here. Bubble flare, double flare, inverted flare.....I use the term inverted flare because that's exactly what they are. A single flare inverted over on itself.
So, let's get started with the parts list shall we? All of the parts I used were off-the-shelf from my local Autozone and should be available at just about any parts store. You will need an inverted flaring tool as well:
1/4" x 30" standard US brake line.
The length is completely up to how far of a distance you need to span. If you have a long rotted section of hard line, you will need more.
2 x 1/4" inverted flare nuts.
This is the same nut used on standard American brake lines. Plentiful, common, and available just about anywhere. I only need 2 because the brake line came with 2
2 x 1/4" inverted flare unions
Again, off-the-shelf from Vatozone. You may have to ask them to let you behind the counter because inevitably some smartass kid will be working there and send you off down one of the aisles.
Now that we have our parts in hand, let's discuss the fix. My leak was in the supply or high pressure line so, I was able to cut the forward portion of the line at the leak, remove it from the car and flare that, along with the patch line on a work bench.
The remaining piece of the line that goes to the rear of the car wasn't as easy. Doing inverted flares on anything while on your back with the tool not supported is PITA to be sure. It took me several tries to get it. I did eventually though. Take your time lining everything up, your patience will be rewarded.
The remainder of the job was pretty straight forward, 3 more flares and put it all back together. All in all, took me about 2 hours which included a couple of cups of coffee, a cigar, and a trip to the hardware store because I couldn't find my mini tubing cutter.
Here's what I ended up with. Yes, that is hose-in-hose. PO did a crappy grease install. In the process of cleaning that up.
Moral of the story, no crazy hydraulic fittings needed. Just $20 of off the shelf parts from a chain parts store and a flaring tool.
Questions, comments or concerns...let me know.
Hope this helps someone!!
