Leak after rear remote grapple setup

[missesalot]

Added a grapple from MTL to my TC45d. Setup with long line set to existing rear remotes, line set provided by MTL with 1/2" Pioneer fittings with quick connects. I have a persistent leak between the male pioneer fitting (grapple side) and the 1/2" to 3/8" adapter. I replaced both fittings, the leak is better but still happening. The leak happens most when the grapple arms are in full open position. Thanks a lot for any advice or information.

 

[ericm979]

NPT threads suck for these kind of hydraulic pressures. They seal by deformation. Which means you have to crank them TIGHT but not too tight or they deform too much. The best thing I have found for NPT hydraulic threads is LocTite 545. I've also tried teflon pipe goop and tape. Those are just lubricants not sealants like the LocTite. With the 545 the fittings don't need to be so tight. It takes a day to cure.

 

[missesalot]

Thank you! I’ll try it. Do I need to take steps to clean the fittings first?

 

[Gordon Gould]

Did you change the 3/8 to 1/2 adapter ? From what you said it wasn't clear, but If you changed the Quick Connect and not the adapter I would try the adapter. Tape always worked for me .

gg

 

[missesalot]

They were taped new from the factory, and pressure tested. Yes I did replace both sides of the leak.

 

[missesalot]

Never heard that about npt treads

 

[ericm979]

Thank you! I’ll try it. Do I need to take steps to clean the fittings first?

You should remove any tape or goop residue and then get the oil off with a solvent that does not leave much of a residue on its own. Spray carb cleaner works ok, brake cleaner is probably ok too. I don't feel the need to follow up with acetone like if I was painting or applying epoxy.