Bursting fuel lines on 88 300TE

[psfred]

I have a problem with rupturing fuel lines on the TE. The original line (the one between the fuel pumps) started getting cracks in it a few years ago, so I replaced it. No problems until recently. Mom is no longer driving, so the car doesn't get used much, at least not until my niece and nephew moved to St. Louis and I seem to get stuck driving over there all the time.

Anyway, I started smelling gasoline again and was going to look under when it warmed up, when my local niece had a service truck pull out in front of her and wipe out the left front headlight and fender on her 300E. So she was using the TE until they got the insurance company to fix it (long story, two of my brother's MBs are registered as Mercurys in spite of having proper titles, go figure). Everything was fine until a two weeks ago when she stopped by my brother's shop to get gas money (she's in college) and said something was leaking on the car. Yup, line between the fuel pumps was split just above the banjo fitting on at the rear pump, spraying fuel everywhere.

I ordered an aftermarket line because I didn't want to wait a week to get a genuine Mercedes, and my brother put it it and all was well, but only for a week, when the new line started ripping.

Now, the new line was soft, which is wrong (it has 75 psi in it, a soft hose will blow up, I'm sure), but I'm concerned I have something else going one here. Anyone else have this sort of problem? Should I be concerned about a blockage somewhere, and if so, where?

We are going to have someone local make up a line with proper material (as in regular fuel line, or high pressure line, or AC hose) in spite of not being properly shaped I'm sure it will work better than the mushy one. Need to get this car back on the road!

Thanks!


Peter

[psfred]

Note that I did replace the front fuel pump because I thought it was leaking -- turned out to be the hose leaking and fuel running down to the pump.

Peter

[Two560Two]

I had a similar issue 2 years ago while I was working on my car. I saw those rubber hoses on my 560sel also rotting, after 20+ years and still being original it was time to replace them. Well, I just used a cheap rubber from pep boys hose and a month later it started to leak again. I ended up going to the dealer and getting the correct host. It is a different material and looks like it expands to a point when needed. I have not had issues since, I would look into using the original hoses from the dealer or even a very good aftermarket replacement

Check the ebay link below, I get something similar from the dealer, just much longer since I didnt know how much I would need

Mercedes W115 W116 W126 Contitech Fuel Expansion Hose 7 0 x 14 5 mm 0009975152 | eBay

[psfred]

My brother called this evening and said he found a shop sorta locally that makes these lines. Had to sliver solder an adapter onto the original fittings, and hopefully the hose is flexible enough to fit, but he was told the material used wasn't actually fuel line, and that the one I just bought was probably worse.

Seems to be quite problem with aftermarket fuel lines these days, as modern fuels will rapidly deteriorate the old style hoses, and he's seen more than one instance where low pressure hose was used in injection systems where it wasn't rated.

So we shall see, my brother is installing the hose this evening.

Peter