So under the rear drivers side near tire i see a puddle this morning and it smelled like diesel so im thinking fuel line but i will put on jack and investigate tonight, off hand does anyone know what size fuel line i need to order/buy so i can source it and pick it up on the way home before i tear it apart only to have the parts store closed? Im thinking i can replace with rubber spliced over the metal line with hose clamps as opposed to buying and getting new metal lines. any ideas or experience anyone can share? perhaps a link to an old thread as i couldnt find any that answered my question.

Thanks
Ron

__________________
1987 300SDL "Rudolf" 239k 8/10


Gone but not forgotten
-1980 F250 4X4 351C Snowplow "The Beast"
-1976 Caddy Eldo Convertible, in triple red. "Red headed Slut"
-2002 Honda Accord EX-V6 loaded 107k, My first brand new car!


*IM A HORRIBLE SPELLER*

Perhaps you could lift the hood and determine the problem prior to thinking "fuel line". The engine has about six different "fuel lines" and any recommendation prior to an investigation is worthless.

Last time I checked the drivers rear tire was not under the hood

__________________
1987 300SDL "Rudolf" 239k 8/10


Gone but not forgotten
-1980 F250 4X4 351C Snowplow "The Beast"
-1976 Caddy Eldo Convertible, in triple red. "Red headed Slut"
-2002 Honda Accord EX-V6 loaded 107k, My first brand new car!


*IM A HORRIBLE SPELLER*

Touche.

The only possibility at the rear of the vehicle are the lines from the tank screen to the hard lines. One is the supply line and one is the return line. They will leak if they are original.


http://www.allpartsexpress.com/ShopByVehicle.epc?q=1987-MERCEDES--BENZ-300sdl--/--L6--998cc--3.0l--Diesel--Fi--Turbo-Fuel--Pumps&yearid=1987%40%401987&makeid=MERCEDES+BENZ%40%40MERCEDES+BENZ%40%40X&engineid=1194083%40%40300SDL++%2F+L6-2998cc+3.0L+DIESEL+FI++Turbo%40%40300SDL&catid=Fuel+Pumps%40%40Fuel+Pumps&subcatid=Fuel+Hose@@Fuel+Hose&mode=PA

Could be the feed hose or the return hose at the tank with fuel running down the steel pipes to the low point near the rear wheel; but, the most likely situation is the steel fuel pipe/s are rusted out, usually in the area where they pass through the rubber grommets which are held in place under steel clamps. A combination of corrosion and abrasion usually, water/salt/grime get trapped between the grommet and the steel pipe, after 20 years the coating wears through and then the steel.

Off hand I can't recall the exact size fuel hose you'll need, I'm pretty certain the steel pipe is 8 mm OD if you can’t find metric dimensioned line, 5/16" ID will probably work, you'll only need a foot or two! Good luck!

I had the EXACT problem about 2 weeks ago. The Feed and Return line from the tank go along the drivers side and directly in front of the rear wheel they turn up toward the tank. They rust out at that bend from being sprayed by the wheel and because the bends are weaker. Your idea of rubber lines is exactly what I did. Chopped both lines in front of the leak and at a convenient place behind the leak. Make sure to get 5/16 fuel line that can carry diesel (If they don't have it ask for trans cooler line, that's what I use, Diesel won't eat it). I would get more then a few feet. Although the leak is most likely small you may find the rust as spread over several feet of line and only broken through at one point.

__________________
Serenity-86' 300SDL 482,000 miles (on a "14" head!)

Thank you all, im sure its the feed return lines too. i think i may even have some 5/16, ill check it out in the morning.

__________________
1987 300SDL "Rudolf" 239k 8/10


Gone but not forgotten
-1980 F250 4X4 351C Snowplow "The Beast"
-1976 Caddy Eldo Convertible, in triple red. "Red headed Slut"
-2002 Honda Accord EX-V6 loaded 107k, My first brand new car!


*IM A HORRIBLE SPELLER*

Consider replacing the lines, two 25' pieces of 5/16 steel tubing are needed. Each one is about 20 feet, no joints. I did the hose repair method to my return line two years ago. The lines should have been replaced instead. Rust from the return line or a outside source ruined the injection pump. A 2 micron Racor filter has been installed with a outboard primer hose pump. The 2 micron may filter out the rust, the stock filters do not.

The replacement of the entire line would be worth the trouble if someone was planning on keep a nice car for a longer time for sure. But the hose patch method gives very good results pretty quickly, easily and inexpensively.

I don't want to sound like I'm challenging your conclusions but I've never heard of something like this happening before and I run a half dozen 603/2 engines and have never had any problem like you describe but I'd sure like to avoid it if I could. How did you ascertain that "rust" from somewhere ruined the injection pump? How did you determine that it was not rust forming in the IP from water contaminated fuel for instance? The 603 secondary fuel filter is a pretty well designed and constucted it would seem hard to believe it would pass particles of a size that would be a problem to the pump particularly.

Rust was found in the first filter at the engine when the engine began running rough. Filters at the engine changed, new delivery valves and springs installed. Running condition got worse over a 500 mile span which included many filter changes. Polished fuel a few times, pouring it back into the tank at the fill. Then returned fuel via the return line when polishing, small plastic filter clogged with rust very quickly. Low fuel delivery found at cylinders 1,3 & 5 during injection pump test.
Rust came from return line or was sitting in tank and got moved around with the force of the return line flow which was higher than normal. Tank screen was rotted away at bottom and may have let go - allowing twenty three years of rust into the fuel system.
Items stained with a very fine rust coating were the fuel heater lines, delivery valve washers and springs, filter housing on engine. I believe this rust may have damaged the injection pump. The pump has not been inspected. Car's background for the first 300,000 miles is unknown. I have fueled the car by hand with a known excellent source for 46 of the past 47,000 miles, water was never found in filters. (Had a 1972 250C that clogged the fuel line with rust at a bend just in front of the rear wheel well.)
If fuel line rust did not cause my problem, the rust in the tank and damaged tank filter did.

So i finally got around to trying to fix my leak, sure enough there was corrosion on the fuel line where it was englosed in the rubber grommet or mount or whatever it is called. i sawed off a 4" piece of the line, slipped a piece of 5/16 fuel line over n tightened up my hoseclamps.

There is a big friggin puddle in the driveway this morning. so im gonna pump out some diesel into some 5 gal cans i have and drive till it's almost empty and try again as im thinking that either I ruptured the other line while moving things around and this job will be easier without diesel pouring out into a bucket and all over me.

Any light anyone cares to share?

__________________
1987 300SDL "Rudolf" 239k 8/10


Gone but not forgotten
-1980 F250 4X4 351C Snowplow "The Beast"
-1976 Caddy Eldo Convertible, in triple red. "Red headed Slut"
-2002 Honda Accord EX-V6 loaded 107k, My first brand new car!


*IM A HORRIBLE SPELLER*

After pumping the tank dry, fuel still came out of tank when the hoses were disconnected. Have a good sized pan in place under tank. Consider pinching hose(s) at tank closed to work on lines.

Rather than suffer that loss of fuel, simply disconnect the return line from under the hood and put it in a 5 gallon container.

Start the engine and go inside for a cup of coffee.

Return to the vehicle and it will have shutdown due to lack of fuel.

Now, make all your repairs.

Drop the secondary and fill it to the brim via a spare container or a siphon hose. Reattach it to the housing.

Fill the tank with 2-3 gallons of fuel.

Start the engine.


This procedure is courtesy of Kerry and it works just fine.

ya except my tank was nearly full. last night i rigged up to hoses to my 12v harbor freight pump (i bought for wvo transfering but hadnt used it yet it was still in the package) i took out 10 gallons of diesel into 2 cans, that left me with about a 1/4 tank which is enough to get to n from work till im friday as i have sat n sunday off to jack around and i will drain the rest out as Brian recommended (really good idea btw)

i bought some assorted 5/16 metal fuel lines and coupling/unions/etc and am thinking that depending how much is rusted i may just replace with metal rather than splicing with rubber. does anyone know if the 5/16 compression fittings fit the mercedes stock fuel line (as im thinking of using a compression coupling) or if there is some adapter available. i only have one car so id rahter gather the parts before i disable the vehicle.

Also, anyone know a p/n on the rubber blocks that secure the 2 fuel lines to the chassis?

thanks
Ron

__________________
1987 300SDL "Rudolf" 239k 8/10


Gone but not forgotten
-1980 F250 4X4 351C Snowplow "The Beast"
-1976 Caddy Eldo Convertible, in triple red. "Red headed Slut"
-2002 Honda Accord EX-V6 loaded 107k, My first brand new car!


*IM A HORRIBLE SPELLER*

if anyone is interested i solved my problem, i realized that i was using 3/8 clamps on 5/16, i used the smaller clamp, and stopped the leak where i used the rubber to replace the rusted line.

next issue, i changed the remainder of the rubber lines and both fuel filters yesterday (the lines on the car were cracked and dated 3/86 so being original and rock hard they needed to go), also did a diesel purge with a 1 gal gas can i modified to act as the purge tank ( a bit dissapointed after 10 mins it was still clear and no black out the tail pipe, looks like ive been getting good diesel tho after much cranking and bleeding air with my mityvac and loosening lines on the IP i got her started. but the primary still has a large air bubble in the filter (like half air half diesel in the space) and runs a bit rough at idle, any idea how to fix this or will driving with my foot in it suck enough fuel into the primary filter to eliminate the air bubble?

__________________
1987 300SDL "Rudolf" 239k 8/10


Gone but not forgotten
-1980 F250 4X4 351C Snowplow "The Beast"
-1976 Caddy Eldo Convertible, in triple red. "Red headed Slut"
-2002 Honda Accord EX-V6 loaded 107k, My first brand new car!


*IM A HORRIBLE SPELLER*