Pipe Threads #$%^&

[3Ts]

I've added some hydraulic lines to my tractor and had to use pipe threads in a few places. I used thread sealant on all pipe threads, but have a single fitting that leaks. I've gotten all but one tight enough to not leak, but the one is driving me up a wall. It is a 1/2" pipe thread quick disconnect at the end of a 6' hydraulic hose and it's leaking around the threads. It is possible to remove the hose but would be a lot of work to do so. I have crescent wrenches up to 2' (in length) for leverage but trying to tighten it further has been unsuccessful. My next step is to see if I can get a deep impact socket to fit over the QD but that will be several weeks before I can get into a town that has one. Any suggestions?

 

[Granthol]

If it’s a drip and you don’t ever need to get it off, jbweld?

 

[chim]

I've done just a little work on hydraulics. I used pipe dope that listed on the can it is suitable for hydraulic lines. No leaks.

 

[TractorGuy]

Aviation Permatex.

 

[fruitcakesa]

Pipe dope and teflon tape has worked for me on NPT stuff

 

[Oaktree]

I have crescent wrenches up to 2' (in length) for leverage but trying to tighten it further has been unsuccessful. My next step is to see if I can get a deep impact socket to fit over the QD but that will be several weeks before I can get into a town that has one. Any suggestions?

+1 on the teflon tape/thread dope. Could it be that the male fitting is bottomed in the female? Trying to tighten further would just strip threads and make things worse.

 

[the old grind]

Permatex No 2, thicker than No 3.

LocTite 567 is a 'high-temp' alternate to 565. These two aren't like the 'green stuff' and most other teflon-based brush-on dopes. They have a working time (~5 min) and a curing time (20-30 min) like many of the company's products. This gives them an edge over more basic plumbing dopes.

IMO, Parker fittings are worth the $$ for better fits, fewer rounded hexes when tightening to stop leaks, and fewer 'do-overs'.

TSC stuff (hoses w/NPT male ends) is among the worst we can easily find. I suggest 'chasing' the lumpy plating off their male NPT threads with a regular die set. :2cents:

 

[LouNY]

Over tightening sae pipe threads causes more problems then it solves.
A small amount of a teflon pipe dope or 3 wraps of teflon tape should be sufficent to seal a npt fitting.
If it needs more the fitting is low quality, teflon tape is not a sealant anyways it is a thread lubricant allowing the thread distortion to occur which is what seals npt threads.

 

[the old grind]

.. A small amount of a teflon pipe dope or 3 wraps of teflon tape should be sufficient to seal a NPT fitting.
If it needs more the fitting is low quality, teflon tape is not a sealant anyways it is a thread lubricant allowing the thread distortion to occur which is what seals NPT threads.

This! ^^^ :thumbsup:

 

[hawkeye08]

Had a sae NPT fitting leak on loader last year, no amount of thread dope/tape would seal it, had to replace fitting.