Are these fuel hoses special? - PeachParts Mercedes-Benz Forum

The Warden · #1 01-03-2003, 03:45 PM

Hello! While pulling the rear axleshafts (unbelievably easy job, BTW), I noticed that the exhaust pipe was wet in one section. Turns out it's diesel fuel coming from a hose above the exhaust pipe, near the differential. There are 4 hoses there. Two are rubber/cloth; the other two are metal. The rubber hoses have a weird-looking clamp on them; I can't see it very well but it looks like it involves a machine screw. I need to replace both rubber hoses.

Are they a special part? Or are they just standard hoses? If they're standard, what's the inner diameter? I ask 'cause I don't want to remove the hoses without the replacements sitting right there, as I assume that as soon as I pull the hoses, I'll get diesel fuel all over me.

If they're special, is there a specific name for them that I can tell the parts guy?

A quick response would be appreciated, as I want to do this before putting the new axleshafts in...the hoses are real easy to get to right now.

Thanks!

JimSmith · #2 01-03-2003, 04:08 PM

The Warden,

I believe the hose itself is not a unique part, per se, but in some cases they come with integral connectors at the ends. If yours is just a slip fit over a pipe nipple with a clamp, then the replacement needs to be no fancier. I have not replaced one of those recently, and I seem to recall they had one end (going to the tank) that had a fitting crimped on it. The bulk hose (Diesel fuel line hose) is available for a couple bucks a meter from the dealer. A meter should do the job, but make sure the end connection is just a slip on arrangement before assuming it is. Good Luck and hope this helps. Jim

The Warden · #3 01-03-2003, 04:19 PM

Okay, it looks like the fuel hose is not special; just looks like clamps on either end (some are the cheap-o squeeze clamps; the others are a clamp with a screw). Again, what's the inside diameter of the hose? Metric and the nearest SAE size would be good; chance are the shop I'll be getting the hose from will only have SAE sizes.

Unfortunately, I'm not at home right now (driving back this weekend), and am currently nowhere near an M-B dealer, so I'll be getting the hose from a local auto parts store...

Thanks!

JimSmith · #4 01-03-2003, 04:49 PM

The Warden,

I have a chunk of hose in my toolkit, which my son just measured that is about 5/8ths of an inch in diameter on the outside, and about 3/8ths of an inch on the inside diameter. This was unused hose that was left over from changing the lines to the injection pump.

If you are going to change the hoses, you will have to drain the tank. I would suggest you find a supplier of Diesel fuel rated rubber hose (should be any decent auto parts place) and take a chunk of the old hose down there to size it up. That way you can be sure. Hope this helps, and good luck, Jim

The Warden · #5 01-03-2003, 06:08 PM

Well, if draining the tank's absolutely necessary, I guess I can't replace the lines right now. I've got nearly a full tank of fuel and nowhere to put the drained fuel.

I was figuring on pulling the hoses and plugging the metal lines long enough to get the new hoses in place, but from what you said, I guess that isn't feasible. So, I guess the hoses get to stay where they are 'till I can get the tank close enough to empty to be able to fit in a container that I do have. Probably gonna be a PITA with the axleshafts in place.

C'est la vie...thanks for the help!

Nate Stanley · #6 01-03-2003, 06:37 PM

Warden,
BTDT with our son's 300D last year.

I just used standard automotive hose and fresh screw-type hose clamps. I believe I got some 3/8" and 5/16" hose and figured on having one size left over after the job was done.

If you never had a pint of #2 Diesel run down your arm, now's your chance. Get in some clothes that you want to burn later, (the only way to get the smell out). Run your tank until it goes past empty (mine gets to E and has 6 gallons left), and plan on having an empty, clean 5 gal plastic bucket handy to catch the rest of the fuel.

One of the lines comes from the fuel strainer that screws into the bottom of the tank and goes to the lift pump, and the other comes back from the IP return line. If the car is backed onto ramps with the rear end in the air, the return lne will leak the least fuel when it is removed / cut in half to replace.

Have a couple of bolts handy to plug the worst of the leaks as they happen and it will be a bearable job.

It will be good to unscrew the fuel strainer in the bottom of the tank to verify it's clean, and your car will be good for another 20 years.

#7 01-03-2003, 06:44 PM

I pulled the fuel strainer out of mine last year when it was giving me heartache. To do that had to drain the fuel. Mr. Stanley gave good direction there. Only thing to add would be that there seems to always be more fuel in there than the best estimates. I ran it until it showed empty. Still overfilled my five gallon and a two gallon. Got all over. Real fun rolling around under the rear of the car in diesel. Doesn't take much fuel to make it a mess.
Well have fun. Wish we could all join you there.

Nate Stanley · #8 01-03-2003, 06:49 PM

O.D. --- that's why you need the clothes you want to burn!

Have a helper ready to supply other containers as needed, you are absolutely right about the possibility of having more fuel than cans.

84300DT · #9 01-04-2003, 08:13 AM

fwiw i changed my (larger diam.) fuel hose coming from the bottom of the tank. this is the one with the attached bolt fitting on one end. i got the replacement from the mb dealer. before i started i trimmed it to the right length and carved an old cork to fit in the end of the hose.
also made another cork to fit the end of the old one. i did not drain the fuel tank.
got underneath with a drain pan, removed and plugged the end of the old hose. then backed off the old fitting from the bottom of the tank. rather quickly changed the old for the new (guess about a 1/2 a gallon spilled on me and not much in the drain pan- lol

- buttoned everything up .. no leaks . great .
took long shower

ps:suggest strongly you use safety goggles to avoid fuel in the eyes ...

Palangi · #10 01-04-2003, 09:20 AM

I would urge you to get the proper fuel hose from the dealer. Using inch size hoses, it can be real hard to stop the leaks. You don't really want to do this job twice.

rwthomas1 · #11 01-04-2003, 01:34 PM

Why not jack up the drivers side of the car and then siphon or pump all the fuel out of the tank? Shouldn't be too hard to do.... I used fuel hose rated for "fuel injection" when I replaced a section on the pump end. Have used it on my other diesels too and never had a problem. RT

MVK · #12 01-04-2003, 09:41 PM

When I got my car, I had a badly corroded metal Diesel line right around the bend at the rear floor pan, which started leaking one day after a high tech car wash. So much for those high tech wash places. I took it to the MB dealer and asked them to replace the whole line, thinking those lines might be high pressure lines.
They charged me 280 bucks. When I came home, I saw all they did was cut the corroded line to the point where it was clean and patched it up with a rubber hose for diesel fuels. and clamped the ends with regular clamps.

I really felt like a fool. But hey I called MB HQ and made a sting about it, and I ended up getting a 150 bucks refund.

MVK

Ken300D · #13 05-14-2003, 07:12 AM

In the process of replacing the differential (now THERE's a fine task) I noticed that the bottom fuel tank hose is moist and drips a drop about every 15 minutes. This is the hose with a brass-colored fitting on one end, and clamped over metal fuel line at the other.

How does one unscrew the old fuel hose fitting without loosening the tank strainer/filter? Is there a place for a second wrench to hold while threading off the hose fitting?

Got the hose already - looks better than OEM. Maybe a nice diesel shower will keep off the mosquitos carrying West Nile Virus for awhile..........

Ken300D

84300DT · #14 05-14-2003, 07:50 AM

ken, i have replaced the line that you mentioned. if you don't drain the tank then there are some suggestions i could make.
the fitting just unscrews like a regular bolt. measure and trim the new hose before you start and put a hose clamp on it in position to clamp onto the metal line. plug the open end with a cork or similiar. then it's a matter of how quicky you can make the switch. you will get fuel spilled but you can keep it at a minimum if you do the above.

personally i hope to never have to do that job again, hehe, i got kinda drenched :p
good luck
duh, i just realized i replied to this similiar question already in the beginning of the thread...

edge · #15 05-14-2003, 09:21 AM

WIll golf tees work to plug these lines while you switch them?