Zero-Five-Two Posted August 19, 2019 Share Posted August 19, 2019 Hoping someone can assist me with an Air Pipe Union Problem on my Tanker. Pipe connections and unions use a very fine thread, as shown below, making it very easy to get a problem. As you can see in the second picture, I've had a bit of an issue while removing the lock nut. Thread inside the nut is in a similar condition The ideal solution would be to find a new union and lock nut, if anyone has a spare. Or, a tap and die to recut these or make new ones, I'm not sure what size it is, even. Measures approximately 7/8" diameter. Thanks for looking, all advice gratefully received Quote Link to comment Share on other sites More sharing options...
MatchFuzee Posted August 22, 2019 Share Posted August 22, 2019 You could try a commercial vehicle motor factor or a hydraulic pipe maker. If you ask for a "hex lock nut and threaded nipple" they should know what you want. Quote Link to comment Share on other sites More sharing options...
marvinthemartian Posted August 22, 2019 Share Posted August 22, 2019 Is it a palm coupling union Rob? Quote Link to comment Share on other sites More sharing options...
Zero-Five-Two Posted August 23, 2019 Author Share Posted August 23, 2019 9 hours ago, marvinthemartian said: Is it a palm coupling union Rob? Yes mate, it is. Service line at the front, so not a major disaster. Union on the pipe is good, and I do have a spare short thread fitting. But it really needs the longer bulkhead one with locknut to mount it onto the chassis. I could replace the whole thing with a modern one, but I'm trying to keep it as original as possible with the fine thread Quote Link to comment Share on other sites More sharing options...
marvinthemartian Posted August 23, 2019 Share Posted August 23, 2019 I'll have a shed hunt at weekend, feeling I've got some lurking somewhere. Quote Link to comment Share on other sites More sharing options...
attleej Posted August 23, 2019 Share Posted August 23, 2019 Rob, I almost certainly have a bulkhead fitting as shown. If not, I can make one quite easily as I should have the 26 TPI die (or whatever TPI it is). Can you just confirm the O/D and length of the fine thread. The coarse end is 1/2 BSP. John Quote Link to comment Share on other sites More sharing options...
Zero-Five-Two Posted August 24, 2019 Author Share Posted August 24, 2019 (edited) Many thanks, Gents, appreciate the assistance. It's one of the best things about this forum, there's always someone who can help you out. I will have a proper measure up of the thing today. Edited August 24, 2019 by Zero-Five-Two Add more Quote Link to comment Share on other sites More sharing options...
marvinthemartian Posted August 24, 2019 Share Posted August 24, 2019 Rob, Martian ones are different. These are what I have. Still looking for the locknuts though. Quote Link to comment Share on other sites More sharing options...
Gordon_M Posted August 24, 2019 Share Posted August 24, 2019 It looks like you could use the Martian type. The male threads would match both ends, they have just substituted a coarser thread where it runs through the bumper to a locknut, so one coarse thread locknut and you are done. It is quite possible they went to a coarse thread at the bumper bore transition exactly because the fine thread locknuts used to seize up and strip all the rest of the thread - just like yours did. Quote Link to comment Share on other sites More sharing options...
attleej Posted August 25, 2019 Share Posted August 25, 2019 Rob, This what I have. The 7/8th 26 TPI thread portion might be a bit short. I would expect to have a 1/2 BSF lock not to suit the one that Marvinthemartian has. Alternatively I could make you one. All I need to know is how long the fine threads should be. John Quote Link to comment Share on other sites More sharing options...
marvinthemartian Posted August 25, 2019 Share Posted August 25, 2019 Have found the locknut. Quote Link to comment Share on other sites More sharing options...
Zero-Five-Two Posted August 25, 2019 Author Share Posted August 25, 2019 10 hours ago, attleej said: Rob, This what I have. The 7/8th 26 TPI thread portion might be a bit short. I would expect to have a 1/2 BSF lock not to suit the one that Marvinthemartian has. Alternatively I could make you one. All I need to know is how long the fine threads should be. John Having had the verniers accross mine, it is 7/8" and the fine thread is about 1.5" long. The one in your picture looks like it would do, nicely. I'll send you a PM Quote Link to comment Share on other sites More sharing options...
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