Are the fittings on the injection lines on an OM603 IP just plain old 45 degree bubble flares? Any problem with trying to make up some new ones from brake line? Can I wrangle the lines in and out without having to R&R the manifold?

I am in the process of resolving a fuel leak from the 3 of the injection line fittings on my 603's injection pump. The fact that I had guysers of diesel shooting out of the tops of the flare nuts instead of seepage around the base of the delivery valve holders should have clued me in, but, in a fit of ignorance, I went ahead and refreshed the delivery valve seals. Naturally the guysers are still going strong, so it's on to the real problem..

When I got the car all the fuel line clips were broken or missing, and though I replaced the clips, my guess is that the vibration the fuel lines had already been subjected to must have fatigued the ends of the lines to the point that routine use finally cracked them. Paying $50 a line is out of the question, so it's either make my own or find a set of used lines somewhere around Denver...

Thanks for any info!

Matt

I don't see a reason why you couldn't bend your own, after all they are just bent tubing.

Length is important though, also I'd imagin the diamiter is as well. Unless you can match them exactly I'd find replacements.

__________________
1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Can you get the right size ferrule or will you reuse the old ferrules?

You can replace the lines without pulling the manifold. Good luck not snapping the old brittle holders. Might as well be ready with a new set of those. Don't forget new rubber pads that make closing the holders a bear.

Sixto

Hatterasguy: I measured the stock lines at .180", and a bit of scrap 3/16 (.1875" nominal) brake line I have at .185". I wonder how cruicial those 5 thousandths are.

sixto: I didn't get a close look at the flares when I had them out since I was imagining the problem to be elsewhere. Is the ferrule you refer to a piece that is trapped on the line just after the flare and before the nut? My line holders are < 1 yr old and they came off without a hitch.

Them's the ferrules. I think it's important to keep them or get new ones because the nut doesn't put direct pressure on the flare as it doesin common brake line applications.

Sixto

I found this thread where grimgaunt mentions fabbing injection lines and s/he says the lines are 'basically bubble flared':

Fuel Line Source

I took a peek at the flares on my lines and they appear to be something less than a 45 degree (i.e. SAE) angle. Would this imply that they are ISO bubble flares (I'm not sure what angle ISO uses?) or could they be something else?

An inlaw family member, master mechanic living in Germany who happens to own his own garage(really-no joke), clued me in. These are ISO flares with a specific curvature that increases contact area as the nut is tightened. BUT the good news is if you have an ISO flaring tool, you can do them at home. AND it is acceptable to use heavy duty tie wrap/zip ties, as long as the little black rubber squares are good, no need to buy MB brand clips.

If that's all there is to it, that's great news -- I can pick an ISO flare tool up locally for $20.

A point of curiosity -- I did note that the mating surface angle of the flare on the lines appears to be something less than 45 degrees, and I found a diagram of a brake line ISO flare that indicates an angle of 57.5 degrees. I imagine there is going to be some amount of distortion as the flare is compressed into the top of the delivery valve holder, but I wonder if there are perhaps multiple ISO flare standards for different applications?

Unfortunately the ISO document that would detail this sells for more than the tool to make the flares.

I suppose I can snag the tool, make a test flare, and snug it in to see what it looks like...

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Bingo, and keep a close IE: test pilot like, eye on it for a few hundred miles. I don't know the spcific angles and radius rates but there are MANY ISO standards. Library of Congress would be able to "lend" the book if you know what to ask for. I think SAE might be a start, too.