Fuel pipe woes -Help!!

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Brendan246
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Fuel pipe woes -Help!!

Post by Brendan246 »

This I presume must be a common problem?

The rubber hose from AC electric pump to SU reservoir was leaking.

Tightening did not happen, so cut a bit off the hose in case split and attempted to re-fix.

I tried new clips etc but did not tighten enough to stop leaks when pump is on.

So bought a new pipe and clips from ESM assuming this would fix the problem.

But to my horror the hose seems too robust (its the new unleaded version) for the clips supplied, as they do not grip the hose on to the brass fittings enough to seal the fuel from leaking that when the ignition is on; come's out like a fireman's hose right above the exhaust manifold, not a good idea.I am bit at a loss now (other than selling it to the mother in law to drive as is on hot days, I cannot see a fix?)

Can anyone help as I now have several hoses a number of broken overtightened clips and a leaking fuel hose?

Recommendations anyone?
In particular I thought?

get the old fashioned plastic hose that compresses better than the heavy duty rubber hose eveyone seems to sell and renew every year to get around hardening/ethenol threats?

is there a replacement top to the su resevoir that might take an olive and a more robust fitting?

ALL HELP OR HINTS GRATEFULLY RECEIVED
MarkyB
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Re: Fuel pipe woes -Help!!

Post by MarkyB »

Are you sure it's not the float chamber overflowing, it would exit just where the pipe connects from under a little ally cover.

"Once you break something you will see how it was put together"
Brendan246
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Re: Fuel pipe woes -Help!!

Post by Brendan246 »

Possible i guess what would cause that??
Brendan246
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Re: Fuel pipe woes -Help!!

Post by Brendan246 »

I think it is not a leaking lid gasket as volume of the leak once float chamber is full is like a burst pipe not a gasket seepage.

Any more views please??

Could float be broken so pump is not shutting off when chamber is full,
Volume of leak suggests pump is running all the time??
bmcecosse
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Re: Fuel pipe woes -Help!!

Post by bmcecosse »

Why an AC pump? Is it a mechanical pump - on the block? Rubber hose and proper clips should be fine. So seems it must be overflowing chamber (stuck/leaking float valve) or too high pressure from the pump!
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Brendan246
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Re: Fuel pipe woes -Help!!

Post by Brendan246 »

Def an Ac pump electrical if i look in the float chamber having taken the lid off
There is a brass looking float at the bottom of the chamber? Not attached
To the lid by anything like some of the newer replacement ones on web sites??

Is something wrong in my chamber??
moggiethouable
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Re: Fuel pipe woes -Help!!

Post by moggiethouable »

Brendan246 wrote:Possible i guess what would cause that??
Worn needle and/or seat in the carb?
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bmcecosse
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Re: Fuel pipe woes -Help!!

Post by bmcecosse »

Non standard pump possibly making too much pressure. Has this problem suddenly appeared - was it ok one day, and leaking the next??
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Brendan246
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Re: Fuel pipe woes -Help!!

Post by Brendan246 »

Has always had a leak but got worse since carb was serviced and even
Worse since i renewed the pipe thinkIng it had split.
mike.perry
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Re: Fuel pipe woes -Help!!

Post by mike.perry »

What car and what engine? If it has a brass float then it floats up and down the centre rod in the float chamber. It sounds as though you have an SU H2 carb which has a shut off pin which cuts the fuel supply when the float is at the top and pushes the the brass forks up which closes the needle valve. To test, disconnect the wire from the fuel pump terminal and carefully remove the float chamber lid and push the forks up. Touch the wire on the fuel pump terminal for a couple of seconds. If the cut off valve works then it should stop the petrol flow
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Brendan246
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Re: Fuel pipe woes -Help!!

Post by Brendan246 »

59 model running an hs2 carb and Ac fuel pump fitted
Before my ownership.
bmcecosse
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Re: Fuel pipe woes -Help!!

Post by bmcecosse »

Fit a proper SU pump........ And who 'serviced' the carb? What was done to it??
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Brendan246
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Re: Fuel pipe woes -Help!!

Post by Brendan246 »

OK think I have got there, AC pump was a red herring upon a closer look it has the SU pump.

I took the carb off and did the float chamber lid test and manually with use of my finger when the forks are lifted up the pump stops and the fuel does not leak anymore.

Looked at blowing out with an air line from needle end of carb fuel blew past the float and did not lift the float up the chamber.

Had to turn the carb upside down to get the float out it was stuck down the chamber.

When I did get it out to clean it it is full of liquid I assume petrol, I was going to put a match near it to see if it had a hole in it, but thought better of it, well before November 5th anyway!! :D

I assume the float is not lifting as it no longer floats hence the valve is not shutting. :wink:

So looked on ESM for a brass float? - Problem

My defective float measures 1.701in
ESM offer either 1.5 or 1.875, in brass floats
My carb has a tag saying AUC944 but no other markings on it I can see?

I have ordered the 1.5 on the basis it does not have to be a snug fit just float and hit the prongs at the top of the chamber and the other one will not go in the chamber so cannot be right?

I presume this is OK?
Trickydicky
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Re: Fuel pipe woes -Help!!

Post by Trickydicky »

If the original float is brass and you can find the hole, cant you just carefully solder it up with say a 75w Iron? you wont need that much heat to make the solder fill the hole.

Richard
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bmcecosse
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Re: Fuel pipe woes -Help!!

Post by bmcecosse »

But first - you must get ALL the petrol out of it....... Can only suggest dropping it in a pan of very hot water - outdoors.......
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