Leaking petcock

The left side fitting that comes out at an angle from the bottom of the petcock leakes. I have tightened it as much as I dare. Leak is not a stream, but if you touch it at the bottom your fingers get wet with gas. It's not the hose. That was checked. Had to hold the body of the petcock with pliars to prevent it from turning -- the fitting from the petcock to the tank does Not leak. To tighten the angle fitting more I'm afraid I would have to grip the body of the petcock valve too hard with the pliars and damage it. The angle fitting has a cone that squeezes on to the female inverse cone at the bottom of the valve body and so would not easily accept a washer. Did I omit something when I put it together? It's just metal to metal. And the right side does not leak -- same parts, same assembly.

The seat could be damaged from previous misalignment, rust flake, over tightening.

Joe Schlaberdowski said:

The left side fitting that comes out at an angle from the bottom of the petcock leakes. I have tightened it as much as I dare. Leak is not a stream, but if you touch it at the bottom your fingers get wet with gas. It's not the hose. That was checked. Had to hold the body of the petcock with pliars to prevent it from turning -- the fitting from the petcock to the tank does Not leak. To tighten the angle fitting more I'm afraid I would have to grip the body of the petcock valve too hard with the pliars and damage it. The angle fitting has a cone that squeezes on to the female inverse cone at the bottom of the valve body and so would not easily accept a washer. Did I omit something when I put it together? It's just metal to metal. And the right side does not leak -- same parts, same assembly.

Click to expand...

Yes, metal to metal is correct. As the two faces are on a slight taper, they seal very well and do not usually need more than a 'nip up'.

So, as concours says, you either have some dirt etc between the faces, missilgnement, or damaged faces.

111Can I "lap" the two parts together like with valves, or,if damaged badly, is it just something to replace? Are there some brand parts that are better than others?

Hi Joe,

Can I "lap" the two parts together like with valves,

Click to expand...

Yes you can. Just check the tapered plug isn't/doesn't bottom out, if so carefully dress a bit off the end.

Dave

Just a little bit of ptfe tape on the taper will probably cure it.

Or, clean up the spigot taper and then apply a thin layer of solder (or just buy a new spigot).

I like the solder coating idea L.A.B. Though why I like to fiddle with something rather than buy a new, very cheap little part I'll never know, but I'll try the thin layer of solder idea. I assume acid flux -- or would anything work that "flows" over the nozzle? Actually this kind of a fix is too quick and easy to ignore. BTW, Was this some common knowledge thing from the days before overnight delivery? Seems like it might apply anywhere you need a washer, especially over an odd shaped part.

Joe Schlaberdowski said:

I like the solder coating idea L.A.B. Though why I like to fiddle with something rather than buy a new, very cheap little part I'll never know,

Click to expand...

I'm sure we that's something most of us do quite often, in some cases perhaps we've had to do, as new parts weren't always easily available.

Joe Schlaberdowski said:

I assume acid flux -- or would anything work that "flows" over the nozzle?

Click to expand...

Just about anything, even multi-core electrical solder.

Do make sure the nut isn't reaching the end of its thread before the spigot is completely tight or it will never seal properly.

Joe Schlaberdowski said:

Actually this kind of a fix is too quick and easy to ignore. BTW, Was this some common knowledge thing from the days before overnight delivery?

Click to expand...

I have no idea. I probably read it somewhere many years ago.

Joe Schlaberdowski said:

Seems like it might apply anywhere you need a washer, especially over an odd shaped part.

Click to expand...

It's possible.

The intelligent use of an "O" ring could do the job. It has worked for me. I sometimes swap tanks on my bike and for some reason, the threads are slightly different between one tank tap and the hose fittings so rather than wind the snot out of it, I fitted an "O"ring and it sealed once the nut was done up to the tight spot.

Dereck

Joe Schlaberdowski said:

To tighten the angle fitting more I'm afraid I would have to grip the body of the petcock valve too hard with the pliars and damage it.

Click to expand...

Try using a crescent wrench/adjustable spanner on the body of the petcock, and then the appropriate open end wrench on either the nuts or the fuel line. That way you can more securely keep the petcock in position without the damage that pliers would do.

Thanks guys. I'm going to try the solder method first. Because I have the solder and don't have an 'O' ring or lapping compound. And I've already tightened the hell out of it. I have to say what I like about this website is the problem solving -- all pitch in if they can and with good engineering. And it's always interesting. Hope to be on the road soon. Cheers.

I'm not as proficient as many on here so I hesitate to offer anything resembling 'advice'. That said I've experienced exactly the same problem. I've replaced every component including the petrol tap and still had the slight weep around the thread on the left hand side: right side, never a problem. Purely by chance I had a small nylon/plastic washer that sits perfectly on the face of the spigot and it's a perfect seal every time, without having to tighten the nut very much at all.

Well, I tried a thin coating of solder over the taper -- and I screwed that up. Since the fitting has an angle to it, the draw nut over the taper can't be taken off. And it can't be backed away hardly at all. It needed flux, that's for sure, to prevent the inevitable beading of the solder. So I aplied flux which immediately migrated to the threads of the draw nut. And, you guessed it, the solder migrated to the threads of the draw nut too. I had to heat it all hot enough to get the solder liquid enough to be knocked out. This obviously would have worked if I could have first removed the draw nut. Or if I could have been more careful in some way, but the unexpected happened (unexpected by me anyway). First I'm ordering an overnight of a new angle fitting as soon as the west coast wakes up. But I'm going to try to clean up the overheated remains and use the small thin nylon washer over the taper approach. Need to ask, was the inner diameter of the washer small enough so the washer rode up the taper a bit? And the outer diameter small enoug so it would fit easily inside the draw nut? Or was the nylon washer more like a ring(I have seen them like that of course)? BTW, when I first took it apart I noticed a tiny amount of "flattening" at the tip of the taper as if it were bottoming from my efforts to tighten it. Which I ignored of course. Don't even know if the tip itself is what bottoms, but live and learn, eh?

Well fellas, I think I have found an easy solution. Rather than go buy a washer (or an 'O'ring, or some tape) an innate laziness took over and I looked at the over heated and ruined looking angle spiggot. I wire brushed it off and tried it to see if the threads were clean enough. A little oil on the threads and it went on, a little stiff, but it went on. The taper was clean of solder. And I decided to 'float' off the tip of the taper with a file where I'd seen that tiny bit of flattening. The dang thing sealed easily. That's all it took. Sorry for all this to-do about essentially almost nothing. And thanks for helping me keep pecking away at it.

Joe Schlaberdowski said:

Well fellas, I think I have found an easy solution. Rather than go buy a washer (or an 'O'ring, or some tape) an innate laziness took over and I looked at the over heated and ruined looking angle spiggot. I wire brushed it off and tried it to see if the threads were clean enough. A little oil on the threads and it went on, a little stiff, but it went on. The taper was clean of solder. And I decided to 'float' off the tip of the taper with a file where I'd seen that tiny bit of flattening. The dang thing sealed easily. That's all it took. Sorry for all this to-do about essentially almost nothing. And thanks for helping me keep pecking away at it.

Click to expand...

:wink:

It's possible the angled spigots are not the originals, as the original (early & late) fuel line spigots all seem to be the straight type.

http://www.classicbike.biz/Norton/Broch ... ochure.pdf

https://andover-norton.co.uk/en/shop-de ... 3-h-style-
https://andover-norton.co.uk/en/shop-de ... y-1974-on-

I make a special tool for holding the stock Norton petcock, no pliers needed. Qick and easy. $25 includes shipping