Fuel Pump Removal ?

[hands_aus]

Hey group,

I am doing my home work so here goes....

I noticed a couple of fuel drops (only about 2 or 3) on the underside of the huge metal cover of the OLD STYLE fuel pump on my 250 sl.

The BRAIDED fuel line from the tank TO the pump disappears into the metal cover and is screwed to the pump. (It seems to be inaccessible with the cover bolted to the body)

The rubber fuel line TO the front FILTER connects to a metal tube (off the fuel pump) that extends through the cover housing.

My intention is to try to find where it is leaking and fix it.

My question……

With the cover mounting bolts removed, will the cover slide along the hoses enough to allow me to inspect the pump and maybe if necessary remove the hoses from the pump?

OR

Do I have to first remove the BRAIDED hose from the fuel tank end (it is a normal clamp, NOT with some screwed fitting) and plug the tank AND remove/plug the other rubber hose?

Can I do this without wasting too much fuel?

What can I use to PLUG the fuel lines temporarily?

Bob(Brisbane,Australia)

[George Des]

Hands Aus--the easiest way to do this is to disconnect the hoses and then drop the shield. It sounds like the main seal on the pump shaft may be the problem. I've been able to resurrect a number of these old pumps that I'm sure a shop will tell you to just go out and buy a new pump at about $300 U.S. Before you go out and get a new pump, try the following: remove the pump and determine if the leak is from the small leak off pump. If so, it's one of a few things (1) The main shaft bellow seal has a small hole in it or more likely the mating surfaces between the bellows and the main pump body are crudded up--if so, this is a simple matter to clean. You just need to be very very careful on how to remove the seal w/o destroying it. If you need to do this let me know and I'll give you more details.

(2) the small rubber seal on the sahft may also be deteriorated and may need replacing--I can give you tips on that as well. The biggest problem encountered when trying to fix these pumps is getting them apart w/o breaking of the many screws that hold the bottom and side plates to the main body and you must be real careful when doing it otherwise you'll create more problems for yourself. Let me know what you determine when you get the pump off and we can go from there.

George Des

[George Davis]

Bob, for plugging the lines I suggest the following: get a short piece of each size fuel line that connects to the tank, plus hose clamps.  Find something that fits in the end of the hoses, like a bolt with an unthreaded section, and clamp it in one end.  Have these ready when you pull the old fuel hoses off the tank, and stick them over the nipples to plug them, then clamp in place.

Naturally, this is unpleasant and slightly dangerous if you have fuel in the tank, but if you're ready for it you won't lose much.

Oh yeah, make sure you can remove both of the old hose clamps BEFORE you pull either hose off.  I had to cut the second clamp off with a dremel tool (lots of sparks) after getting gas all over the place.  Most uncomfortable.

If the hoses down there are old, you'll want to replace them all, mine were quite brittle.

I think the hoses are 12mm and 8mm, but I'm going from memory and could be wrong.

Good luck, have fun, and be careful.



George Davis
'69 280 SL Euro manual

[hands_aus]

Hey George Des AND George Davis,

Thanks for replying.
I think I will take the car for a run and use as much fuel as possible before I attempt this job, that way there won't be too much fuel in the tank to worry about.
George Davis, I like that idea about a bolt, hose and clamp. I think I will use that setup.

George Des,  I will stay in contact. I know I will need more info.

To my inexperienced eyes, the tank seemed to be nice and clean when I looked into it recently (I replaced the fuel sender). The fuel filter screen in the centre of the tank was clean too. So hopefully the fuel pump is not full of crud.

A further question about the BRAID COVERED fuel hose FROM the tank to the pump.

It has a screw connection at the pump end. Do I have to have a new hose made to replace it OR can I have a connection made on which I can clamp normal rubber fuel hose.
OR are there metal adapters available?

Great starting info, Thanks

Bob(Brisbane,Australia)

[George Davis]

Bob,

I think the hose from the tank to the pump comes in 2 versions.  On my car (1969) the screw fitting is a separate piece and the hose is clamped onto it.
On earlier cars, the screw fitting is part of the hose assembly and they are crimped together.  At least I think that's the case, because I was sent one of these incorrectly when I ordered some other fuel lines.
For what it's worth, a hydraulic outfitter could probably supply a fitting it you have the crimped assembly and want to convert it to the clamped type.  The braided cover on the fuel hoses is just a reinforcement over rubber, so I'd say any fuel line can be used.  However, I did find the braided stuff at a VW parts store, so you might be able to find it with a little checking around.


George Davis
'69 280 SL Euro manual

[George Davis]

I just re-read your post, you said you have the crimped type.  Sorry, not awake yet!

George Davis
'69 280 SL Euro manual

[W14]

Hi Bob,

I found that if you undo the 2 bolts for the protective cover then it can be moved around enough to get an open-end wrench on the fittings near the pump body. Don't try to force those fittings if they are corroded, because they are aluminum castings and may crack relatively easy.  I suggest pump removal in that case.

Another good trick that someone else suggested to block a fuel line, is to use some needle-nose visegrips, with suitably sized sockets over the jaws.  You can squeeze, and keep the hose closed, without harming it.

You may not have to replace the crimped fittings.  There were some smaller fuel lines with crimps under my hood (between injec.pump and fuel damper?) that were cracked with age.  With nothing to lose, I carefully removed the crimped hose, revealing standard metal line underneath.  I just slipped standard rubber fuel hose over the metal line.



Will W14
1965 230SL 4spd
Victoria,BC

[George Des]

Bob,

George Davis is right. I've seen two different versions of the connection. One is a simple screw on type of elbow where you can clamp a length of hose onto. the other has the elbow screw on fitting crimped directly to a lenght of braided hose. Did you figure out the fuel elak problem yet.


George Des

[hands_aus]

Hi Will and George

Will thanks for the info about the protective cover. Did you need to clamp the hose that you replaced on those crimped fittings or did it crimp as you pushed it onto the pipe?

George, I have not been able to get to the job yet. I will do it as soon as I have some spare time and by then I hope to have used most of the fuel in the tank.


Bob(Brisbane,Australia)

[W14]

Hi Bob,

After I removed the crimped portion, what was left underneath was "normal" metal fuel line, and I had to use a clamp to fasten the new rubber hose to that line.

Will W14
1965 230SL 4spd
Victoria,BC