Expert advice needed on fuel return line at banjo union - Mercedes-Benz Forum

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post #1 of 2 (permalink) Old 03-20-2013, 02:00 PM Thread Starter
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Expert advice needed on fuel return line at banjo union

A severe leak has started from the banjo union through the crush washers at the fuel return line out of the front carb. I am having a hard time finding new crush washers that are the right size. I found some for a drain plug, installed them and there is still a good size leak. (see photo)

I was wondering if I were to install a barbed fitting (see second photo) that would connect into the carb fuel return and to the hose, and bypass the fuel return valve, what type of problems would I be creating? It looks to me like the lever that is supposed to open and close the valve at the bottom of the fuel return valve was never working properly and the valve was always open anyway. Please let me know what you all think.
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post #2 of 2 (permalink) Old 03-20-2013, 05:03 PM
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For washers you might try to find some aluminum ones that fit, or just cut some out of thick gasket material.

The diaphragm in the valve gets stiff and brittle. be careful or you will crack it and start leaking.

I rebuilt my valve with Viton, I got a small sheet at Graingers. If you need some let me know. Originally the brass stem was peened over to hold the diaphragm, I had my machinist drill and tap the end, now the diaphram is held by a screw.

Those valves are impossible to find and MB Classic does not sell the diaphragm/pin anymore. I was considering machine a bunch of the brass pin to sell along with new Viton diaphrams.

I have heard many remove it, but I do not know how.
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