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Discussion Starter · #1 ·
I developed a steam leak on a loco. Not a big one as the burner can maintain 20 lbs pressure, but no more. I can just hear it with my aids turned way up. Ran it on rollers but the weather was too humid to see the vapor. Luckily had fittings in the spare drawer to make an adaptor to take the place of one of the pressure relief valves so I can charge the boiler with air to get up close. The leak is from the banjo fitting for the pressure gauge. It was aimed to vent the steam under the boiler wrap so I thought the leak was the boiler itself. Now need to locate proper size seals. Have to be very careful as only 2 1/2 threads actually grip the boiler. Being lucky is good.
 

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Discussion Starter · #3 · (Edited)
I should have said, find them, have them here I'm sure. Cliff, a great and knowledgable person who is sorely missed, usually sent extra seals with a purchase. As a last resort can also make them using several layers of thick brown paper or currency dipped in steam oil, along with Permatex High Temp thread sealant for that added personal touch.
 

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Have you done the soapy water test around the fittings to determine exactly where the leak is? Hard to understand from your photos what is going on or exactly where the leak is in order to recommend a fix.
 

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Discussion Starter · #5 ·
Cliff, thank you for the advice. The pic was only the fittings I put together to charge the boiler with air. The leak was from the banjo fitting for the pressure gauge, no pic of that was posted. The fitting for the pressure gauge is right up against the boiler wrap, and the steam leak was directed to under the wrap. While every thing was cool and I could get up close was much easier to find. The fix will be very easy, small seals and some thread sealer, pressure test, and it'll be on its' way. Thanks again.
 

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Discussion Starter · #6 ·
I found why the banjo nut only grabs for a couple of threads then stops. There is this little sleeve screwed into the boiler that extends to under the banjo nut stopping it from putting pressure on the seals. Also slightly lowering the diameter of the hole of steam to the fitting. I am curious to it's purpose. First going to grind down the top of the fitting where the screw driver slots are to about half of what they are now allowing the nut to grab another full thread allowing more pressure on the seals. Another option is to remove it altogether. That shaft you see on the bottom of the hole is the throttle shaft. Does anyone know the purpose of that extender sleeve? Thank You
 

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Curious - that little sleeve looks like a steam pickup as it seems to be attached to the regulator - designed to pick up steam above the maximum water level. It is most often under the steam dome but no reason it shouldn't be elsewhere.

Robert
 

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Discussion Starter · #8 ·
Robert, what you said makes perfect sense, to keep water from entering the capillary that feeds the gauge.
I chose option 1: deepened the screw driver slot and cut 1/8" off. Reassembled and found the nut now applying pressure to the seals. Air testing showed that the mini gauge doesn't come off the peg till about 10lbs of regulated pressure and the gauges disagreed by that amount through out the range. First test I got to 45 lbs and one of the test hoses slipped from the fitting. When my pulse rate went back to normal did another test and everything held.
 

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