Pipe dope on hydraulic line connection?

[nbennett]

The connection is between a metal line and a quick disconnect(IPT?) on a BX2200. I'm sure that it was previously over tightened. I used teflon tape on Friday and will watch for leaks. I had worked on same fitting before and it did not leak for a couple of weeks. When it started leaking again it was still tight. This all started when my neighbor left to visit her grandkids for a month and left the lawn mowing and tractor in the hands of unknowing family members. I have already spent about 8 hours repairing damage that they caused.

 

[Soundguy]

It's not clear what type of thread we're discussing here

Pipe thread (tapered) is generally the only one where tape or better still, dope would be recommended. Other types of hydraulic fittings seal by other methods. (tapered seats, "O" rings, etc)

Ditto this 100%.. pipe thread where thread deformation make she seal will benefit from dope.. but the orb and taper fit fittings ( JIC, compression, flair.. etc.. ) won't at all..

soundguy

 

[jmfox]

Yep, the dope would only help prevent seizing, not leaking.

jmf

 

[Michaeltymcnamra]

Here is a website that gives solid data on the various types of hydraulic fittings, and explains why some need pipe dope,
and others do not, and instead rely on the o-ring:

https://www.parker.com/literature/Tube Fittings Division/Pipe_Fittings_&_Port_Adapters.pdf

 

[Tractor Seabee]

I use LOCTITE 567 Thread Sealant when needed.

Used in the chemical processing, petroleum refining, pulp/paper, waste treatment, textile, utilities/power generation, marine, automotive, industrial equipment, gas compression and distribution industries. It is also recommended for industrial plant fluid

As with any sealant, paste or tape, care must be used to insure the material doesn't contaminate the hydraulic system.

Do not forget to clean all existing compounds and oil from both male and female threads. Teflon tape is getting a bad rep for contaminating systems with particles. It can play havoc with hydraulic system inerds and almost impossible to get all out. In my pipe-fitting days I had a 10 man crew re-piping three Navy ship 5" gun mounts. Thread sealant was not well specified and the company chose Teflon tape. The sailors started up the systems after we finished and they worked for 15 minutes and quit. Found Teflon particles through out the systems and clogged orifices in all valves. Took three 24 hr days to remove and clean all the piping while the sailors disassembled the system mechanisms and cleaned them. The inspector required us to install a bunch of strainers. Our company lost a bundle on that job and it was an expensive lesson learned. I have never used Teflon tape on sensitive system since. The liquid types work OK as Ultrarunner admonished above.

Ron

 

[CalG]

Obviously, the use by relatives have made conventional sealing methods irrelevant.

I suggest a new tractor with ALL complimentary attachments the only useful solution.

Attitude is everything...................

 

[Texasmark]

I never found a pipe dope locally for 2500 hyd. systems with NPT threads, but have used regular plumbers dope, the blueish gray stuff with the applicator in the lid. Never had a problem.

 

[Gary Fowler]

Pipe dope of any kind is not meant to seal but rather to act as a lubricant so you don't gall the threads when tightening. Proper threads that haven't been overtightened will generally seal with any pipe dope used. One containing copper or/and graphite will work well for hydraulic systems.

Pipe dope will sometimes help seal a bad thread by allowing additional tightening. A turned thread from overtightening usually needs to be replaced to stop it from leaking.

 

[Lineman North Florida]

I have used Teflon tape on hydraulic fittings for years and never had one problem, I must be lucky.

 

[RickB]

I have used Teflon tape on hydraulic fittings for years and never had one problem, I must be lucky.

Or, like myself, you simply understand how and where to use it.