Injection (hard) line mounting - PeachParts Mercedes-Benz Forum

babymog · #1 03-02-2011, 10:24 PM

While mounting my fuel lines today, I was thinking about the regular "I just replaced a fuel line and it broke again" postings that we see.

The fuel lines are not perfect, depending on the position of the IP (timing) the lines might need a little adjustment.

NEVER leave the fuel line under stress, always tweak the bends a little (carefully) to relieve stress in the injector line or you will be sending it to an early grave. It should fit at both ends and all clamps without significant stress.

I don't know if or how this is covered in the FSM, I believe that it is mentioned in the section about timing the IP.

toecutter · #2 03-02-2011, 10:40 PM

so, i'm not the only one...

i went through 3 #6 cylinder lines in as many months, no matter what i did to relieve stress or pre-load. benz saw fit to change the original routing of the #6 line on the om603. only after finding a used line of the original configuration did the problem end.

the lines on the toyota units are at least twice the guage of steel, i have yet to hear of one ever breaking. in comparison, the benz lines seem pretty thin and weak.

Diesel911 · #3 03-02-2011, 11:15 PM

Also, all of you Hard Line Clamps need to be intact.

The longer and thinner they are the more prone they are to cracking.

babymog · #4 03-03-2011, 10:56 AM

Not even close to the only one.

They seem to break at the injector more than anywhere else, seldom in the middle of the line even if there is a wear point from broken clips.

I did have one break on a Cat engine in my first motorhome (inside the valve cover), filled the crankcase with several gallons of fuel until it hit the crank, I experienced my first diesel runaway on the freeway going through Chicago.

As far as the #6 re-design: I have a set of the new "inclined injection" lines (for the 3.5L cars) for my new engine, didn't like the design so I adjusted the angle on a set of 3.0L lines from the original engine to install instead. I don't know why #6 was re-routed, I would assume for better durability, but perhaps it isn't a good design. I have a couple of spare sets around, hopefully I won't need them as I've had to pound a line shut on a manhole cover once (the aforementioned Chicago incident) to get home, don't want to do it again (they never fail in the driveway).

jt20 · #5 03-03-2011, 07:50 PM

This raises a question that has always stifled me.

"What is the correct way to bend lines so they do not incur unreasonable stress?"

After putting 60x lines on my 617 for the sake of scientific proof, they quickly broke. <300miles. I blame this on the incredible bending I had to do them so that they would fit.

unionbricky · #6 05-08-2012, 08:25 PM

i have searched and searched, were are you guys buying your new om602 injector lines?
i had a #5 break at the ball end,
might as well do all 5 and the new clips,
i searched PP, but only found the clips,
1990 602.962

Diesel911 · #7 05-08-2012, 08:51 PM

You can replace all of the Lines if you want to but normally only one of the Lines has a problem.
I would be nice to have a spare Straight Line that you could use anywhere.

wildest · #8 05-08-2012, 09:12 PM

Quote:

I have a couple of spare sets around, hopefully I won't need them as I've had to pound a line shut on a manhole cover once (the aforementioned Chicago incident) to get home, don't want to do it again (they never fail in the driveway).

Add hammer and anvil to the mobile toolbox (I actually have them in the trunk right now).