Hydraulic fitting sealant ?

I've had good results with teflon tape but its not universally approved. The worry is getting bits of tape loose into the flow and into small orifices or valves.

Loctite seems to have several concoctions intended for hydraulic fittings.

Gerald J.

When I used to build feed trucks we only used La-Co Select Unyt or something to that effect. Avoided tape for fear of strands getting into the system. Always had good luck on 2500 PSI system. Now I use a Loctite brand that dad left behind but the bottle is worn and cant read the number on it. It's red in color if that helps. Have good luck with that as well.

Steve, I can agree with you on the dope AND tape for sealing threads, but I only did that with water and natural gas connections. Never a problem with that. Typically the hydraulics I did were 3/4" and less and the guys I worked with weren't that careful. 

i've always used thread tape on hydraulic hoses.as said earlier, just hold the tape back a one or two threads to keep it from getting into the system.a contractor buddy of mine turned me on to "Blue monster thread tape".this stuff works great.give it a try you'll like it. http://cleanfit.com/blue_monster_ptfe_thread_seal_tape_70885.shtml

Totally correct on crappy made pipe threads these days.

Old machinist friend I used to work with told me tapered pipe threads should turn in fairly easily about three turns by hand, then wrench it for another 1 to 1 1/4 turns. There are "dry seal" tolerance pipe thread dimension that the taper should seal the fluid, and any tape or whatever you put on would be to aid in disassembly later. Good luck buying something like that off a hardware shelf! But I have found, if your threads fit together pretty close to described above, and the sealant or tape you use is rated for the fluid contact, you'll be fine. If your threads go together not so well, relying on the dope for sealant will likely give trouble sooner or later.

 I had a connection on my water heater that wanted to leak on me with tape or pipe dope. My brother said use Permatex form a gasket. It never leaked again :) 
 I just use the little can of pipe dope I've had in the shop for the last 20 years anytime I put hydraulic pipe fittings together and have never had a problem.

an old sealerfrom the piston engines on the dc-6,dc-7 aircraft,called TITE SEAL worked every time on all aviation fuels and hydraulic fluids.....

Many many people above are saying "never had a leak", and it's true, because honestly most threaded fittings don't leak if done even close to correctly by someone with rudimentary mechanical skills. Think about what you're reading: guys who've used Teflon "never had a leak", guys who use Loctite "never had a leak", guys who use Napa "never had a leak", etc.

Like I said, many things work just fine, and the contrary is true, if you do encounter a leaky fitting, it can be a real bugger to get anything to seal it. Best thing for a truly troublesome leaky joint is to make a new joint there, one that works with Teflon, Napa, Loctite.....