Fuel tap leak

[WolfieParticipant @wolfie]

My fuel tap has a small but steady drip when closed. Do I need to worry about this??

[WolfieParticipant @wolfie]

[Neil WyattModerator @neilwyatt]

Not if you're fireproof.

Neil

[John HinkleyParticipant @johnhinkley26699]

Unless you are talking about some sort of mechanical device, I'd suggest that you get your prostate checked!

John

[Paul Relf-DaviesParticipant @paulrelf-davies37806]

Fuel tap for what? The only experience I have with these would be with the fuel tap on my BSA D1, which is a push-pull action to open/close the flow and uses a small cylinder of cork on the plunger as a seal. this can dry out over time and shrink/disintegrate, causing a leak.

I think replacement cork seals are available, but if not, I've heard of people 'whittleing' then from a wine cork. They drill a through hole the size of the plunger's inner spindle then carefully carve away the remaining cork until they et a good fut in the valve.

cheers

P.

[colin hawesParticipant @colinhawes85982]

I think I have seen fuel tap corks at one of the Villiers spares sites. Colin

[Mark P.Participant @markp]

Wolfie, my old T120 tap used to leak like a sieve, didn’t worry too much about it. Replacements can be had off ebay cheaply.
Mark P.

[WindyParticipant @windy30762]

Modern petrol contains ethanol and has a detrimental affect on some seals and taps on older bikes.

**LINK**

Windy

[MetalmuncherParticipant @metalmuncher]

Drop it in boiling water for 10 minutes, you'll find it will swell enough to stop the leak.

[Mark P.Participant @markp]

Mole grips on the pipe.

[WolfieParticipant @wolfie]

Yeah an internet search told me about the corks, got some new ones on order!

Just occurred to me I have some bits of Delrin lying around, I wonder if they would make a good seal??

Edited By Wolfie on 28/11/2015 20:17:32

[Mark P.Participant @markp]

To be honest Wolfie I wouldn’t bother faffing about with the old tap. Ebay is the place lots of new ones at good prices and ethanol proof too.
Don’t know about delrin and petrol but give it a try.
Mark P.

[colin hawesParticipant @colinhawes85982]

I would expect delrin to be too rigid for a petrol tap "cork" ;it needs to compress a little. Colin

[martin perman 1Participant @martinperman1]

I've used PTFE bar to make seals that may work.

Martin P

[martyn nutlandParticipant @martynnutland79495]

You most certainly do need to worry about this.

I have the same type of push on/off tap on the Austin Sevens' under-bonnet tanks, that if they leak (mine do), can deliver very accurately a drip directly onto the hot exhaust. Then it's whoosh! No car and perhaps no me.

Don't faff about with wine bottle corks, or Teflon inserts (I have and it doesn't work) or with trying to over-tighten the joint with Mole Grips. Get new seals or, better, a replacement tap. These are readily available for the Seven and I expect they are from the specialist suppliers for whatever it is you have.

Good Luck

Martyn

[vintagengineerParticipant @vintagengineer]

Removing ethanol from petrol is relatively simple. You need a clear plastic container with a drain tap at the bottom. Fill with 10 ltrs of petrol and 1 ltr of water and shake vigorously. Leave it to settle overnight and the ethanol and water will settle to the bottom, then just drain this off.

Posted by Windy on 28/11/2015 16:32:58:

Modern petrol contains ethanol and has a detrimental affect on some seals and taps on older bikes.

**LINK**

Windy

[John Stevenson 1Participant @johnstevenson1]

I don't think you have anything at all to worry about.

His fuel tap was leaking two years ago and by now all the fuel has run out.

[thaiguzziParticipant @thaiguzzi]

If it's leaking externally, there's a fair chance it's leaking internally, so fuel flows to the carb, float needle may not handle it, and then it's passed the carb into the inlet port. Motor in the wrong position, In valve open and it's in the engine. Not good.

Fuel taps HAVE TO work and be in GOOD condition.

[Speedy Builder5Participant @speedybuilder5]

Martyn, I guess your 7 is pre 1933 then ? I made the corks for my '32 RN from wine bottle corks back in 1998 – and they are still working OK.
BobH

[Perko7Participant @perko7]

My understanding is that modern fuel contains ethanol as a means of raising the Octane rating without the risk of detonation, to counteract the removal of lead. Control of detonation was the main reason why tetraethyl lead was added to 'leaded' fuel. Since the use of lead was banned, fuel chemists have tried a number of other ways to maintain the octane rating of the old 'super' fuel without the detrimental effects of unleaded fuel. Ethanol appears to have been the most successful of those. My 1975 VW Kombi and my 2003 Subaru both run well on current 95 Octane fuel containing 10% to 15% ethanol with no degradation of seals or other components. In fact they run better on that than on normal 91 Octane unleaded, and give matching fuel economy as well.

[Brian HParticipant @brianh50089]

According to various posts on the Austinsevenfriends site, premium grades of petrol do not (yet) contain ethanol. I have been using this in my 1931 Seven for a couple of years and fitted the push/pull fuel tap with a kit of Viton o-rings and have not had any leaks, not from the tap at least!

Brian

[Russell EberhardtParticipant @russelleberhardt48058]

Ethanol shouldn't degrade cork seals, after all cork was used to seal wine bottles and if kept moist by laying the bottles down they would last for decades. However modern wine bottle corks are a mixture of cork and resin or even entirely plastic. Petrol may well attack those.

I did use wine bottle corks in the 1970s for relining a wet clutch but wouldn't do that with modern corks.

Buy the correct seals or make sure that any cork you use is the real stuff.

Russell

[Brian GParticipant @briang]

I wonder if any problems from ethanol in petrol only affect post 1968 vehicles, as before then Cleveland Discol was readily available? If so, could it be due to the use of plastics instead of cork?

Brian

[Richard S2Participant @richards2]

Direct modern replacement of certain parts on old machinery can be an advantage in respect of safety and/or reliability.

I tend to prefer keeping something in it's original form wherever possible. I use quality repair kits for Fuel Taps and add mesh filters where there weren't any fitted. These examples are early/late 50s and are in full use after refurbishing-

Edited By Richard S2 on 21/03/2017 11:49:37

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