Removing injector lines

[wwheeler]

I want to replate my fuel injection lines on my 2.8 M130 motor. I have read many threads about people removing the lines but never anything specific about how to do it. Is there any special trick? How is the best way to capture the fuel in the lines? Unlike modern fuel injection systems, I don't believe these systems hold pressure when the pump is off. Correct?

Is there any danger of contamination inside the lines when cad plating?

Thank you for the help.

[jameshoward]

Wallace,

I am no expert but I removed my lines in order to remove the injectors and pump. If your injectors could do with a clean, now's the time to do it. It shouldn't cost much but get it done by a pro. Many diesel shops will be able to clean and test them for you if you wanted to go ahead with that.

As for removing the lines, it's very straight forward. What isn't nearly so easy is putting the lines back together again. Take a LOT of photos and measurements. Also, note that - I think I recall - with some engines, the screw that you remove at the end of the engine that also holds the fuel lines holds some of the internal workings in place. So, don't turn over the engine with the bolts out! The fuel in the lines isn't under much pressure, but they hold fuel that will leak all over the place. Someone may be able to recommend a clever way to get around the problem of fuel leaking all over the engine, but I went for spill soil and a drip tray.

In summary, getting them off is easy. Getting them back together again exactly as they were was hard. I took a lot of shots and still had problems.

I can't speak to the contamination issue, but can't imagine for a moment that this form of plating could affect the fuel.

JH

[Garry]

Hi Wallace,

When you have done it can you let me know if there was any problems.  I have a spare set of lines here that I was about to cad plate and will be interested to see how you go.
Garry

[Mark280SL]

James,

Was it difficult to put them back on because it was difficult to determine which one went back in the same spot it came from originally or because of the tight working space you have when wrenching them firmly back into place correctly? I don't imagine you can accurately torque them, or can you?

quote:Originally posted by jameshoward

Wallace,

I am no expert but I removed my lines in order to remove the injectors and pump. If your injectors could do with a clean, now's the time to do it. It shouldn't cost much but get it done by a pro. Many diesel shops will be able to clean and test them for you if you wanted to go ahead with that.

As for removing the lines, it's very straight forward. What isn't nearly so easy is putting the lines back together again. Take a LOT of photos and measurements. Also, note that - I think I recall - with some engines, the screw that you remove at the end of the engine that also holds the fuel lines holds some of the internal workings in place. So, don't turn over the engine with the bolts out! The fuel in the lines isn't under much pressure, but they hold fuel that will leak all over the place. Someone may be able to recommend a clever way to get around the problem of fuel leaking all over the engine, but I went for spill soil and a drip tray.

In summary, getting them off is easy. Getting them back together again exactly as they were was hard. I took a lot of shots and still had problems.

I can't speak to the contamination issue, but can't imagine for a moment that this form of plating could affect the fuel.

JH

[jameshoward]

Mark,

No torquing required that I know of. The difficulty was simply one of remembering or trying to figure out which line went where and which bracket held it on. If you take a long look at the set up you'll see what I mean when you imagine the whole thing and numerous bits of bracket in pieces.

As for the working area, it's not too bad. See if you can get a fuel or brake line spanner - it's a ring spanner with a small slot cut in it to allow you to pass the line through it. They're great and I used one to replace my brake lines. I didn't have one for the fuel lines, but it would  have helped.

The secret is lots and lots of photos and measurements.

JH

[bpossel]

What helped me was to have the hood off.  Also, lay all the lines out on the bench (or ground).  Lay them out as if they were installed.  Make sure that the front of the lines are all parallel.  This will help show you which lines go where.

The bolt that holds the bracket on the head does not hold any other internal parts.  It does however go through the head casing and into the oil chamber.  So when you reinstall, put a dab of sealer on the bolt threads to keep the oil from seaping out when the engine is running.

The hardest part for me was to reinstall the front bracket with new rubber spacers.  It was difficult to get the lines lined up and squeezed into place.  I dont think I could have done this with the hood on and in the way.  Most likely when these cars were rolling down the assembly line, the fuel lines were installed as a "set" (already bound together with the front bracket). Over the years as they have been removed, they have been bent a bit, so alignment becomes a challenge.

[Naj ✝︎]

Observe the pipes in front of the valve cover.
On the outer perimeter you have pipes to injectors 4,5 and 6 top to bottom.
Inner perimeter piped 1,2,3 top to bottom.
Also note that Pipe to injector #1 fits to port 6 on the inj pump and pipe to injector #6 to port 1....

Remove the pipes on the outer perimeter first, then the inner.

Refit in reverse order.

Useful wrenches (if you like collecting tools):



Hope this helps

[wwheeler]

Thank you for the warnings about documenting. I will heed those at all costs!

It would seem that the injector end of the fuel line would be the best to remove first. Since it is the highest point, only a small portion of fuel will come out. Once that end is removed, you should be able to plug it. The plug should create a vacuum to hold the fuel in the line until you can get a continer under the pump end.

If the injector has some kind of check valve, it may create a vacuum to hold the fuel in the line when the pump end is removed first. I am not sure if this is correct, but it seems logical. Any experience with this?

[Benz Dr.]

If the engine hasn't run for a while there will be very little fuel in the lines. Not enough to worry about.
I've seen some internal rusting problems after plating because the lines are dipped in acid to clean them before plating. Spray some oil into the lines as soon as you get them back from the plater to prevent rust forming and then plug the ends.
Sometimes lines are plugged with rust or other blockages. You can fish a wire through them sometimes and get them freed up again. I blow compressed air through all lines BEFORE I send them out for plating and also before I install the lines. Nothing worse than finding that the lines are plugged and you have to start all over again.
I'm pretty sure a plugged line would damage the IP. You don't want to go there....

[waqas]

I was having this discussion with Matt (Merrill) yesterday, and the question came up: what is the customer prep process before cad-plating?  Do you need to remove any corrosion from the lines before sending them to the plater? (or do they take care of that)  What about random nuts and bolts? (rust, etc)

[bpossel]

Hi Waqas,

I used a brass wheel on a bench grinder to clean all of my parts before I sent them to the platers.  While they do dip the parts before hand, I noticed that the parts that I had cleaned and smoothed the most came back looking the best.  I sent along some new parts to cad also.  Those came back looking much better than the older parts.
Bob  

quote:Originally posted by waqas

I was having this discussion with Matt (Merrill) yesterday, and the question came up: what is the customer prep process before cad-plating?  Do you need to remove any corrosion from the lines before sending them to the plater? (or do they take care of that)  What about random nuts and bolts? (rust, etc)

[waqas]

Bob,
Thanks for the info!  It's time I started prepping all the parts for plating. Did you by any chance compile an easy-to-email list of all the pieces you sent for plating?  

Thanks again

[bpossel]

Hi Waqas,

I did.  Hard to really make it descriptive, so I took lots of pictures also.  See attached.
Bob  

quote:Originally posted by waqas

Bob,
Thanks for the info!  It's time I started prepping all the parts for plating. Did you by any chance compile an easy-to-email list of all the pieces you sent for plating?  

Thanks again

Download Attachment: cad.jpg
76.55 KB

[waqas]

Thanks Bob!