190d clear fuel line? size, type (Viton?), etc.

[ssorange]

Hi,

I need to change the fuel lines in my 190d and I've got a few questions:

First, my 190d has the fuel line going up to the filter and returning to the IP is clear. I cannot remove this w/o destroying the line so I can’t take it off to size it. Is there a reason it is clear? Is it a special type of fuel line? What sizes is it and where can I get it?

Second, The fuel line going through the primary filter to the IP. This line looks like standard fuel line. Is it 7.5mm ID?

3.) My local auto parts stores do not carry metric sizes can you recommend a mail order place to buy fuel line?
4.) what type of material should I use? Is there any reason to go to Viton?

Thanks to all ahead of time.

[dieseldiehard]

Are you using Bio? Bio fuel is the only reason for using Viton or clear hose.
Someone recommended it to see if there are air bubles in the line when switching between Bio and diesel (assuming 2 fuel tanks and a selector valve).

I have seen clear line used with diesel fuel but I doubt it holds up for long esp with hot fuel running thru it. The most important place for Viton is the small 3mm return line from injector to injector and back to the filter assy. The large Viton hoses are too soft and easily get crushed or kinked and block flow so unless someone finds thick walled Viton (VERY expensive!) I would forget using it except for the injector return lines.
BTW even on a "diesel fuel only" car Viton is holding up just great on the 2 cars I used it on and runs $3.25 a foot for the 1/8 in (3.2 mm) hose. It takes just a Meter for a 6-cyl engine, so 4 ft is enough with some left over = $14 from McMaster Carr. I order on line and they delivered very fast out here on the Left Coast. YMMV
I am sure they have all the other hose you need, and I think you better size it first before ordering. If I had access to hose I'd tell you right now, sadly I am far from there.
http://www.mcmaster.com/
Oh there's always Phil! check the BuyParts button on the header of the page!

[19DDiesel]

I also have 190dz' [2] of em
and they each have two clear fuel line hoses'.
bango on each end.
one from spin on filter to side of IP
and one from other side of IP returning to spin on filter.
hose seems stiff, not plyable!!


Mark

[ssorange]

Originally Posted by 19DDiesel

I also have 190dz' [2] of em
and they each have two clear fuel line hoses'.
bango on each end.
one from spin on filter to side of IP
and one from other side of IP returning to spin on filter.
hose seems stiff, not plyable!!


Mark

YES!!! I checked on all my 190d's (3 of them). They all have a pair of clear hose, attached to the banjo fittings on the IP and spin-on filter assmb. and are very hard..as if they will crack open if I attempt to move them. Can I use regular fuel line in their stead? What size?

[Endust]

While those hoses may seem hard, you will find they are still suprisingly strong and flexible. You can undo them and they wont break. Having had the IP on my car out several times lately I can assure you of that.

[ssorange]

They are 20+ years old. I would feel better if they were new since it is my wifes car.
Should I just go to the MBZ dealer? Doesn't anyone know the size?

thanks!

[dieseldiehard]

I am sorry I posted all that jazz about Viton. I thought you were referring to clear plastic hose added by someone to see if air bubbles are in the fuel supply line, that being the hose that carries fuel to the IP. (Yes, its a WVO thing).

Now after revisiting this thread I believe what you are looking at is the rigid plastic lines with factory installed banjo (metal) fittings on the ends. These aren't going to fail. They turn dark from fuel attacking the plastic or some kind of chemical change, put new ones if you are making a show car O/W I wouldn't waste any time or $$ on them! Sleep well and don't worry about them!

If however you are set on replacing them, buy the complete lines at the dealer, its VERY difficult to install the banjo fitting on that rigid hose, you need special clamps (ok make them out of hard wood if you really want to DIY) and finding the rigid plastic is going to be nearly impossible.

Call Phil re: the rest of the bulk black rubber hose. Forget Viton! Go to a dealer if you need it tomorrow morning.