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Triumph TR3 - Fuel Line Tap

As long as I'm deep in the engine bay, I'm leaving no stone unturned in the search for oil leaks. With oil weeping from the where the fuel pump attaches to the block, I'm ready to replace the gasket and stem the flow. It was while detaching the fuel lines from the pump that I learned about the siphoning action from the fuel tank. My particular TR3A does not have a fuel tap to cut the flow from the tank. Should there be one? For those that have taps, what type of connections are there into and out of the tap? Does it take flexible or metal hoses?

From the bridge of the Valdez,

Bill Stagg
1961 TR3A
Bill Stagg

Hi Bill-My 59 (TS42561) had a fuel tap, but my 60 didn't. I think the hoses were rubber,in&out.

Hi Bill:
I had a fuel tap on my '58 which I took the trouble to rebuild with new corks. It still leaked as do the taps on old Brit bikes so I just came to the point on the frame where the tap was with the copper gas line and went with neoprene line to the pump.If you have to remove the line at the pump to clean the sediment bowl or replace the pump you can jack up the front of the car or clamp the line with a small "C" clamp.
Don't forget to put gasket goo on the threads of the pump bolts because the holes in the block usually go right through.

If you don't have a "petrol stop-cock", don't worry about it. TRA won't take off points as they claim that removing it is a "safety related" improvement. But I never got points because I have one. Get some tubing from the auto section at Walmart at about $0.50 per foot and some small hose clamps. Make sure it has "gas-resistant" printed on the outside of the rubber hose, so it won't dissolve.

BTW, the priciple is not "siphoning" but mere "gravity". The pump is lower than the bottom of your gas tank.

As for the corks that leak, Chuck is right. But I used a short (about 1/2" long) length of this same rubber gas line hose instead of the cork. Cork comes from the bark of cork trees (logical, isn't it ?) and has veins in it that will eventually let the gas leak through. But since the ID of the rubber hose was too big for the spindle in the stop-cock, I carved a "plug" out of cork that goes onto the spindle before I put in the rubber hose as the plug. I carry a spare "just in case". It has worked fine for 3 years now.

Some day, I plan drop one of those new synthetic corks made of a mixture of plastics (invented and patented by a Canadian) into a jar of gasoline. If it's not affected by the gas, I'll patent that idea using this new "cork" for out gas line shut off valves and we can all have "original looking" cork plugs for our TR3A "petrol stop-cocks" - even if no one can ever see them, but we'll know, won't we ?

It's good to have a stop-cock. I turn mine off when I park for a long time in a "shady" area - so no-one can drive my "TRusty" away. Well if they try, the float bowls for the carbs become empty in less than a city block and they would think they ran out of gas.

Don Elliott, 1958 TR3A
Don Elliott

Bill, Why not just go to a good automotive parts store (Napa or equivilent) and buy a quality petcock made for 1/4" I.D. neoprene gas line, use stainless hose clamps and forget the cork? Since the judges don't seem to care, what's the difference? I like the idea of being able to have a positive shut off when having to access the pump, since clamping the fuel line isn't really a good idea if repeated too often. Mike
Mike Gambordella

Great idea, Mike, that sounds like a smart way to go. I plan to replace all gas hoses under the hood while I'm in there. My hoses on the carbs have a wire/twist arrangement used for tightening them on the metal nipples. How are those made?

Hope things are warming up out your way!

Bill Stagg

Hi Bill. I'm not sure what you mean by "wire/twist arrangement" - doesn't sound right. I don't know what comm. no. your '61 is, but according to Bill Piggott's Original Triumph book, early TR3's w/ H6 carbs had "flexible rubber and braided fuel pipes" both between the carbs and from the front carb to the fuel delivery pipe. Later, rubber lines were used, but without any clamps! There should be a solid u-shaped pipe between your carbs w/ rubber ends to connect to the carb pipes. I went out and bought a dozen stainless hose clamps of the continually slotted variety and all new neoprene line to replace eveything from the end of the tank's feed pipe(below the pump at the frame)all the way to the rear carb w/ hose clamps at every junction. That's about as leak-proof as it gets for connections, and I figure better safe than sorry. Haven't bought myself a petcock yet, but it's on the list. I want to start re-assembling the front of the motor, fan, rad, etc. before I take any more stuff off - starting to forget what's what. I still have to rebuild the carbs too.
And no, it's not warming up out here! Snow in tomorrow's forecast...but 50 on Sunday. Have fun. Mike
Mike Gambordella

While the later TR3A's had supply lines of rubber, just slid on, TRA do not dock points in a Concours event if you have small clamps to tighten keep the hoses securely on the pipes. I don't know what kind of clamps they'll accept (or reject), but they say clamps on the rubber hoses are "safety related".

Don Elliott, 1958 TR3A (early - still with original braided hoses and "Banjo" fittings)
Don Elliott

Don and Mike,

Thanks for the continuing info. I've picked up some new gas line, but I did not find a gas-friendly shutoff valve. I'll keep searching.

I'm a fan of hose clamps, and I'm using "traditional" wherever I can, but all I've found for the gas hoses are the smaller ones to which Mike referred.

Thanks, gents.

Bill Stagg

Hey guys, the 1/4" inside diameter fuel line I picked up is a verrrry tight fit on the fuel line pipes. A length of 5/16" ID line I have is too loose. The old hose I'm replacing has an inside diameter just between these two others.

What is the correct size of the fuel line, or do I just have very tight-fitting 1/4" ID line?


Bill Stagg

This thread was discussed between 10/03/2003 and 16/03/2003

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