There's a big difference between sewer and water lines, and then high pressure hydraulic lines. Thread sealant is called "sealant" for a reason. The instructions in my hydraulic kits from CNH called for using thread sealant on the NPT fittings. If you read about threads and sealing, you can understand how its the peaks and valleys that can never align perfectly due to how pointed or rounded they are. This causes spiral leaking under pressure.
Pipe dope on hydraulic line connection?
- Thread starter nbennett
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ArlyA
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I used to work for a boom truck manufacturer Terex. On the NPT fittings in there hydraulic systems, we put Teflon dope on them. We had used tape but discontinued its use after fragments of it was found in valves.
Rmart30
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Almost 30 years working on construction equipment. Never used pipe dope, thread tape what ever on anything but pipe fittings period...... JIC or FFORS, BOSS fittings, you can put whatever you want on the threads and it will still leak because thats not what seals them. We rarely have any newer equipment that has pipe fittings on them.
ultrarunner
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We used a dab or aviation permatex on the studs when rebuilding flatheads... it kept coolant from weeping up the threads.
I still have dad's curved iron-pipe-bell "chisels" for packing oakum and final tightening of the lead. Another couple of years and they will be antiques and can be the subject of a "do you know what these are" on TBN!
