Clear Fuel Tubing - PeachParts Mercedes-Benz Forum

Oldwolf · #1 05-04-2009, 10:42 AM

OK...a newbie question.

I am preparing to replace vacuum and fuel tubing on my 93 300D. I noticed that there is some clear fuel tubing around the injector pump. Can I use regular black tubing there instead or is it advisable to replace with the clear for observational purposes?

The clear tubing now on the engine is hard as a rock so I am guessing it is original.

Where can I find the clear tubing other than at the dealer?

Thanks!

75Sv1 · #2 05-04-2009, 10:45 AM

The clear tubing is naturally hard. I think Phil sells the assemblies. I did replace mine recently. I think if you look at local hydraulic hose repair places they might carry some tubing that will work.
Tom

Oldwolf · #3 05-04-2009, 11:00 AM

Thanks. I didn't find it for sale here so I thought maybe people did not use it.

As for vacuum tubing, I am guessing I need pretty much one size, right?

The exception looks to be the turbo vacuum tubing, which looks larger.

I guess I need to take some measurements with my calipers.

I am hoping that my Bentley manual, which should arrive tomorrow, has some of this pertinent information.

bob_98sr5 · #4 05-04-2009, 11:53 AM

old,

i deliberated on this one too, but in the end, i just used fuel line hose (biodiesel resistant) with some hose clamps. works fine.

bob

WD8CDH · #5 05-04-2009, 05:46 PM

If you go to "rubber hose" just snip off the hard clear tubing about 1/2" past the nipple and slip the rubber hose over the clear stub and nipple for a better fit.

Oldwolf · #6 05-04-2009, 10:43 PM

WD,
That's a good tip, thanks. Why did MB use clear tubing? I guess so that you could see if there was fuel flowing in case of starting troubles?

Diesel911 · #7 05-04-2009, 11:26 PM

Quote:

Originally Posted by Oldwolf

WD,
That's a good tip, thanks. Why did MB use clear tubing? I guess so that you could see if there was fuel flowing in case of starting troubles?

If my 84 had the original clear tubing on it lasted many times longer than a Hose made of Rubber would have; so that may be why Mercedes used it.

That being said I replaced mine on my year and model with rubber hose but I used a Butane Lighter and heated up the ends that were on the metal barbs and yanked or pried them off while they were soft enough to do so. Be careful the Metal Banjo retains heat well.

compress ignite · #8 05-04-2009, 11:35 PM

It's a lot more flexible the first Ten years.
I believe MB used it because of it's durability (20+ years).

[Yeah,I don't think you're getting the old stuff off the nipples without cutting
it off Longitudinally.Although Heat does work wonders.]

Here's the Cyrillic Pictogram and Part(s) Numbers:

Beagle · #9 05-05-2009, 01:24 AM

Quote:

Originally Posted by Oldwolf

OK...a newbie question.

Can I use regular black tubing there instead or is it advisable to replace with the clear for observational purposes?

No, DEFINITELY NOT rubber hose between the filter and fuel pump. Fuel erodes and dissolves rubber hose and the sediment will gum up the fuel pump elements and injectors. A reinforced plastic hose is OK but will soon harden and not last as long as the original.

Oldwolf · #10 05-05-2009, 08:19 AM

Aha! Now that makes sense Beagle. Is the only source a MB dealer?

Beagle · #11 05-05-2009, 09:01 AM

Quote:

Originally Posted by Oldwolf

Is the only source a MB dealer?

I guess so. That tubing is a special high temp. resistant plastic – not something you are likely to find in an auto-spares store. While fuel flow keeps it cool engine running it will reach engine temp when off. As hose clips are less than ideal on small plastic hose I think you would be well advised to replace with original – then you can forget it

.

Oldwolf · #12 05-05-2009, 10:28 AM

How do I know if it needs changing? Apparently it is a hard material (which mine is) but it is not leaking. So maybe I don't need to worry about it.

Beagle · #13 05-05-2009, 10:38 AM

Quote:

Originally Posted by Oldwolf

How do I know if it needs changing? Apparently it is a hard material (which mine is) but it is not leaking. So maybe I don't need to worry about it.

If not damaged or leaking reuse it! They invariably crack due to being flexed when working on your engine - they harden with age. Just treat it like glass and you won't have a problem.

Diesel911 · #14 05-05-2009, 10:51 AM

There is a Thread somewhere where a Member bought only the tubing itself (I believe it is made by Tygon; sometimes visable on the tubing). I believe the Member said he heated up the plastic and quickly shoved in on the the Barb of the Banjo fitting.

And indeed my tubing cracked when being flexed so after that I planned to change all to rubber hose.
My thought was that if I keep the remaining old plastic tube it might crack somewhere on the road at some inconvenient time when I do not have the tools to deal with it.

With Rubber hose you only need a Screwdriver and a knife to cut the Rubber Hose to fix it and the Hose is available at any Autoparts store at close to $1 a foot.

charmalu · #15 05-05-2009, 03:26 PM

when these fuel lines are new, they are not hard as they are now after 20 plus years. when they are new, they are clear and they have flexability to them. But not soft like a rubber hose.

If they are dark brown, they are hard and brittle and will break.
I broke the one with the 3 way connector that comes off the filter and goes down to the IP. Tweeked it a bit too much, and snapped like a potato chip. this was on Friday afternoon

so thought a local independent shop might have the tubing and I could just replace it. NO. It is a dealer item only. so on tuesday I got it, and munus $40.00 and something I was up and running.

Figured if it lasted 22 yrs, might as well keep it as designed and not cut corners. don`t like sitting on the side of the road watching the world drive by.

. thinking about replacing the other two.

Charlie