Fuel Line Routing - Tank to Pump

[NoEcm]

Just finished installing a Dansk fuel tank and I'm in the process of running the supply line between the tank and the pump.

This is how the fuel line was routed when I got the car but something does not seem right.

Should that support clamp be there? If not, what should that clamp be used for?







Thanks!

[Jonny B]

Went out and took a look at mine - no clamp as you show.

Note that the fuel pump is gravity fed. If the supply line is raised it can give a fuel feed problem at low fuel  levels.

[Pawel66]

There is a thread with pictures on how these lines look like, cannot find it now.

There is no such clamp to the best of my knowledge.

However: i think it is a good practice to install additional flow through fuel filter on his line - then you may need a clamp to hold the filter.

[waltklatt]

No clamp as I remember, but looking at yours, I see why its there.
Your fuel hose is a long rubber hose that runs under the differential pumpkin, that's a no-no.
Fuel hose should run to the underside of the trunk floor and run in a metal line to the motor, close to the transmission tunnel.
Suspect there is an incorrect fuel line setup on your pagoda.
Walter

[Pawel66]

Some picture here:
https://www.sl113.org/forums/index.php?topic=27318.msg195992#msg195992

[NoEcm]

Final solution:



Since the Dansk fuel tank doesn't have a fuel screen in it and the one inside the fuel pump had a tear in it and it's not available separately I added the above fuel screen inline between the fuel tank and the fuel pump. This is a 141 micron wire mesh screen made by WIX.

At a 141 micron filtration do I need to make the fuel screen finer or coarser?

[Tyler S]

NoEcm, You are missing an important bracket between the short pump retrofit bracket and the car’s mounting point. Because your car originally came with a long pump, This bracket is needed to keep the pump inlet and tank outlet at the same height on the short pump. If you ever loose prime with less than half  a tank then the pump will cavitate. Being a 250sl this bracket is somewhat different than the 280’s that originally came with the short pump. This bracket is difficult to find.  However, the newer style bracket can be modified to fit by drilling new holes in it.

[NoEcm]

Thanks Tyler,

So I need to install bracket #105 on top of bracket #138 and then mount it to the frame? This is what I currently have now:

[Tyler S]

Thanks Tyler,

So I need to install bracket #105 on top of bracket #138 and then mount it to the frame? This is what I currently have now:

Exactly! 👍🏻 Do you have the bracket? It seems they go missing when a short pump is retrofitted in.

[NoEcm]

No, I'll have to purchase or fabricate the bracket. Any idea what the height of this retrofit bracket is?

Unfortunately my Great Uncle had very poor mechanics work on this car while he owned it. You'd cringe if I told you some of things that the mechanics did.

[Tyler S]

The bracket appears to be Around 47.5mm. This however is the newer style bracket I modified to fit. Maybe someone with an early setup could measure an original upper bracket. should be pretty close.

[Pawel66]

Look at the picture there. SLS do not have bracket for short pump and advise to buy the early one. I did that and it did fit with some modifications.

https://www.sls-hh-shop.de/main/en/mercedes-230-280sl-w113-47-fuel-tank-c-3_76

[BaronYoungman]

It bears  emphasizing that your pump must be below your tank to keep the gravity feed otherwise if it loses feed you will have to use the bleeder screw to reprime the pump also I have the inlet filter assembly you are looking for please PM me I have some nice used ones. Bob

[NoEcm]

The bracket appears to be Around 47.5mm. This however is the newer style bracket I modified to fit. Maybe someone with an early setup could measure an original upper bracket. should be pretty close.

Thanks a bunch for that measurement. 47.5mm will be the height of the bracket that I'll fabricate.

I have the inlet filter assembly you are looking for please PM me I have some nice used ones. Bob

PM sent

[Tyler S]

NoEcm, the bracket should look just like the one in the diagram I posted above. If you notice it has a slight offset. This offset moves it away from the tank about 3/4 inch. The bracket is attached to the body using the 2 threaded holes in the support channel that hangs down from the car.

[Pawel66]

If you plan to have the pump cover - fit it together with the bracket, if I may suggest.

[Shvegel]

Not sure if this helps but I found this picture showing a pump bracket I was working on for a friend.  It has a pretty good view of the original upper bracket.  I know the 2 "fingers" my bracket are mounted on are off of the fore and aft axis by 5 degrees with the rear finger being left of axis when viewed from behind.

[NoEcm]

A special thanks to Tyler S. for his assistance in this matter:

I went ahead and purchased the bracket as follows:




The new bracket installed onto the body:




Short pump and bracket mounted to the new bracket:




And finally the fuel pump protective cover installed:




Thanks again for everyone's assistance!

[Tyler S]

Absolutely! 👍🏻 Where did you purchase the bracket from? I should probably correct mine at some point.

[NoEcm]

The bracket I installed was purchased from Authentic Classics and was a straight bolt on to both the frame and to the short fuel pump bracket:

https://www.authenticclassics.com/Fuel-Pump-Mounting-Bracket-230SL-250SL-280SL-p/auth-009205.htm