Hydraulic leaks

[J_J]

He could try Loctite red or blue if NPT


Loctite Purple 5452 is the best to date.

http://www.henkelna.com/us/content_data/141299_LT5557_5452SSF448695.pdf

 

[Mace Canute]

If it's NPT, I think a threaded pipe sealant with Teflon would work best.