Fuel leak

[Tony Lilly]

1979 GT - went over a ramp (roadworks) bit too fast. Immediate smell of petrol. The leak is from ?? just above rear axle drivers side when the ignition (and fuel pump) are turned on. Doesn't leak otherwise. Don't think any pipes have parted because it got me home. Don't have time tonight to jack up the car but any pointers would be welcome before I call in the cavalry. I did glance at a fuel diagram and thought fuel pump? or expansion tank or absorption chamber.
Thanks all.

[Vic Butler]

Morning Tony.
Park the car outside, turn on the ignition so the pump operates then have a look underneath to see if you can spot where the petrol is leaking. Does the fuel pump stop ticking or does it keep on going even with an occasional tick?
. Vic Butler

[Ian F]

Hi Tony,
probably not what you are asking about - but I have had fuel spillage after going over bumps due to a rusted/perforated top on the fuel tank. It sits hard up against the boot floor and if not properly rust proofed it will rust out eventually. Very small perforations can leak a surprising amount of fuel!

IanF

[Tony Lilly]

Thank you both - finally got to it. My snag is that my day job interferes with enjoying my MGB !! It was the fuel pipe joining the pump to the metal fuel pipe - about 9 inches long. Mine was rubber and somehow had split, not fully, about an inch from the pump end. Can't quite figure out how going over roadworks ''ramp'' a bit quick had caused that. However repaired with a piece of 8mm fuel pipe until I receive the new piece which is steel coated and the correct piece. (£14)
Thanks again

[Vic Butler]

Evening Tony.
I hope your new fuel pipe is ethanol proof as that can cause rubber to rot.
. Vic Butler

[Ian McKay]

Ethanol in our fuel....Bah! Humbug!

The Wizards at Bicester Aerodrome sell ethanol removal kits.

Not cheap mind you...and possibly quite hazardous...if you are worried by fire.

Search 'Ethanil'......

[Tony Lilly]

Thanks guys
''Ethanol proof'' - blimey! I'm getting the new real piece from Tim Kelly MG centre in Cornwall who really is very helpful. I'll mention it to him however.
Thanks

[Peter Cresswell]

If the flexible pipe between the pump and the pipe to the front of the car split, I would urge you to replace all the rubber pipes in the fuel system. You should also check the state of the metal pipes from the tank to the pump (on cars with the pump underneath the car - late cars use a rubber pipe from the tank to the pump) and from the rear of the car to the bulkhead. These are steel and rust through. A change of pump would also be wise as the diaphragm will not be ethanol proof, and finally change the float valves to viton tipped ones. You are then ethanol proof up to 10%. A filter before the pump and a second one before the carbs will ensure the carbs receive clean fuel.

I've recently returned from a holiday in France, where they sell E85 petrol - 85% ethanol. Avoid at all cost!!!! Fortunately Sans Plomb 98 is readily available and works well with lead replacement additive, and SP 95 works ok with lead replacement plus octane booster. The 10% ethanol is about as much as an MGB can tolerate.

[Tony Lilly]

Meant to close this one off - thanks for all your help. Fuel pipes checked and the suspect hose replaced. Mentioned the ethanol to my man and was assured that the new flexi-steel pipes are fine. Then found out that the connection at the pump was dodgy so replaced the pump with an electronic pump (£50 odd) Boom!
Thanks.