What is correct way to use thread sealant?

[Gary Fowler]

Most hydraulic fittings are tubing type with male/female connections or O-ring seal. The threads just hold the connection tight. Thread lubricant (it is never a sealant when the threads are made up properly) is used to lubricate the joint so the proper torque can be applied without stripping or galling the threads. If the threads are made up correctly, then regular grease could be used. Some products called thread sealant just fill in the gaps on improperly made threads and lubricate the threads so they glide smoothly to the point of tightening and therefore may or may not seal the joint and prevent leaks.

SAE pipe threads (and any other threads) can be tightened to the point of deforming the threads which can cause leaks with or without using thread sealant. In my career as a Quality Manager and Inspector, I have seen more threaded joints leaking from overtightening than any other cause.

 

[LD1]

Get a bottle of loctite 545 and be done.

 

[sixdogs]

I'm removing the loader fittings that go from the boom to the junction box ( when you remove the loader) and replacing that box with a quick disconnect version--Kubota M7040. Ho much torque do I use to tighten hydraulic fittings? Others here said to not overtorque so any questimates on how tight to screw the hoses and into fittings and then the fittings to the box?

 

[LD1]

I am sure there is torque specs out there somewhere.

I just go as tight as I would with a standard wrench, if it was on a bolt instead of a fitting. Just kinda a feel thing.

 

[WranglerX]

How tight?... Just tight enough it does not leak..... If you break/damage the fitting or round off the hex portion and it sill leaks it is a bad fitting or "O" rings ( or sealing washers) and no amount of force will fix situation.... Experience is best for applying proper toque... Listen to little voice in back of head that says "it may be tight enough"...

Dale

 

[radios1]

I知 sure it will work fine. It should say something like water, fuel and oil. Teflon will work with oil.

I used teflon tape on the fuel lines on my oil burner, the teflon disintegrated quickly, I think a week!. and that's a low pressure use.. I now only use pipe dope for oil.. chlorine, as used in cutting fluid, is murder on teflon too, I machined 100 teflon parts, only to find out the next day, that they swelled up,(it took a bit of time)..

 

[WranglerX]

Something to read if interested.....

Thread seal tape - Wikipedia

Dale

 

[sixdogs]

Good advice. I know how tight most things should feel so I'll go with that. It is kind of a feel thing.

 

[bcp]

CAN OF WORMS OPENED!

That doesn't work very well either. They often crawl out of or farther into the fitting before it is screwed together.

Bruce

 

[sixdogs]

Something to read if interested.....

Thread seal tape - Wikipedia

Dale

Good reading. Makes a good argument for thread paste.