Thread Sealer

[Charlie]

Hi Everyone:

I have a WH hydraulic Autopilot that is leaking a small amount of oil. I also can't get it bleed properly. When I first installed it I was able to get all the air out but after awhile it sucked in more air. It is my theory that Teflon paste is not strong enough to hold the hydraulic forces at bay. Can anyone recommend an industrial grade thread sealer? I was thinking of using Permatex but wasn't sure if it was a correct use of the product.

[motion30]

Locktite makes a hydraulic thread sealer expensive but that is what you should have used from the start It will not gunk up the insides of youir expensive equipment and will not leak

[capngeo]

Try this, I've had good luck with it on hyd systems

[GordMay]

Use a Pneumatic/Hydraulic Sealant, such as Loctite 545 or Permatex 54540.

Do NOT use Teflon (PTFE) tape on Hydraulic/Pneumatic systems.

[captain465]

I agree with capngeo............I used to use teflon tape on hydraulic systems that would operate at 3000psi and over. Just be carefull that you start the wrap at least one thread from the end of the fitting, so that you do not introduce a threat of teflon into the system.

[boatman61]

I agree with Gord....
Do not use PTFE on hydraulics...
Fine with gas/water etc but not for hydraulics.....

[Charlie]

Thanks everyone. I have excluded teflon tape. I am not that neat and a small tear of the tape can cause problems in the system. The Loctite and Permatex products that Gord and Motion 30 recommends look good to me. The advantage I see goes to Permatex for the following reasons 1) Permatex literature says that it is formulated to work in oily conditions and 2) Once again the literature states that the fittings can be removed for reassembly. Hopefully I never have to do this again but if I do I don't want to have to use a 4' long cheater bar in my lazaret to break the threads sealed with Loctite. I have used other Permatex products and it has always lived up to its claims. Does anyone have any real world experience with Permatex hydraulic sealant?

[GordMay]

See "The Path to a Leak-Free Hydraulic System"
➥ http://www.useloctite.com/filephotos..._to_a_Leak.pdf

[Charlie]

Thank you Gord that is a great addition to this thread.