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MG MGB Technical - Fuel line from fuel pump

I need to replace the flexible fuel line from the pump outlet to the metal fuel pipe. I will jack the car up on the pump side only so the fuel runs to the "other" side of the tank. Any tips as to how to avoid fuel syphoning out during the changeover? I recall slackening a union somehwere allowing air into the system. I made a note of it but now can't find it! Any help appreciated. Many thanks Michael
Michael Beswick

Michael - Just loosen or remove the fuel line at the fitting on the upper right side of the tank. Once that is done, the car can sit level (or any other attitude) and the fuel will not run out. Cheers - Dave
David DuBois

What year? On my chrome bumper I had to change a pump at the roadside after travelling about 60 miles and had no fuel siphoning out. After that I replaced the flex pipe in the garage and it was running out all the time. I put this down to the slight vacuum that develops in the tank when running if you have the correct vented filler cap fitted as these have a spring-loaded valve.

Changing the pump on the rubber as long as I kept the pipe ends up high where the pump is i.e. above the tank I didn't have any siphoning either. You might get a bit running back from the carb pipe, but that is all.

From your wording I suspect you have chrome.

As you can change the sender with about 1/4 tank and the right rear corner raised I'd expect to have to do something similar if slackening the tank fitting, if the fuel level is above that then it will run out.
Paul Hunt

Paul - "What year?"

On NA spec cars, any year prior to 77 has the fuel line routed through a fitting at the top of the right side of the tank and loosening or removing the fuel line at that point will keep the fuel from being siphoned out of the tank. Cars after 76 have the fuel line routed through the sender attachment, which is much lower on the tank it would be necessary to have the right side of the car jacked up and the tank less than completely full, or have the ability to hold the fuel line at the pump above the level of fuel in the tank. Cheers - Dave
David DuBois

Thanks all. I should have been more specific- 1969 UK spec roadster.I will combine all the ideas. Part due tomorrow!
Michael
Michael Beswick

David - it's possible with the US filling limitation that the tank-mounted exit pipe *was* above the level of fuel in the tank. But UK cars didn't have that limitation and can be completely filled, which will put the fuel level above that exit pipe on the side of the tank.
Paul Hunt

This thread was discussed between 12/07/2009 and 16/07/2009

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