What is correct way to use thread sealant?

sixdogs · Jan 19, 2019

I'm going to use thread sealant for the first time and am looking for pointers. Pic below. With tape, I wrapped three times and left the first two threads with no tape.

With thread sealant, how important is to leave the first two threads clean? How much sealant do I use and do I have to put it on all threads? How tight do I tighten? What else?

Most important, will it reliably seal my loader connections? I have to replace the connection where the loader hoses disconnect when you remove the loader. I'm replacing the junction box with a quick disconnect lever setup and don't want any leaks. I mean, I could still use tape. Advice welcome.

RNeumann · Jan 19, 2019

CAN OF WORMS OPENED!

The mechanic I learned from didn’t like the Teflon tape on hydraulic fittings. He used the paste. I’ve never heard that you should leave two threads without sealant. Most methods/products work fine if done correctly/per instructions. Your Teflon definitely falls in that category. I found a thread sealer that the folks who make loctite make. It isn’t loctite and looks like teflon paste but smooth. If I find it I’ll post an edit with a link. I’ve also seen good results with good old red loctite. It’s seals well but obviously can be a PITA when it’s time to disassemble the part.

Edit-
Permatex(R) Pipe Joint Compound - Permatex

I usually go about as tight as I can with about a 8” lever. Most wrenches are longer so I “choke up”. A lot of it is done by feel and with experience. The bigger the pipe/fitting the more leverage needed though. The above reference was for CUT sized stuff- 3/8”-3/4” ish stuff.

If you do end up using Teflon tape make sure to wrap in the same direction as would would to tighten the fitting.

4570Man · Jan 19, 2019

I don’t like the Teflon tape. Aside from the possibility of getting pieces in the system you can’t back the fittings up any and that’s a frequent need with hydraulic parts. And my experience is the Teflon tape usually leaks.

Diggin It · Jan 19, 2019

I did a couple recently with dope and just made sure I didn't get any in the ports themselves. Didn't worry about keeping two threads clean.

But I've never done Hydraulic fittings before, so I may have messed up.

oosik · Jan 19, 2019

I use a Loctite product specifically for hydraulic fittings. Goop it on all threads, screw it down tight. It's off white and about the consistency of tooth paste.

sixdogs · Jan 19, 2019

oosik said:
I use a Loctite product specifically for hydraulic fittings. Goop it on all threads, screw it down tight. It's off white and about the consistency of tooth paste.

I'm the OP on this. Is the sealer in the first post OK for hydraulic fittings? I can't recall but think it's the only sealant they sold. Anyone know?

RNeumann · Jan 19, 2019

sixdogs said:
I'm the OP on this. Is the sealer in the first post OK for hydraulic fittings? I can't recall but think it's the only sealant they sold. Anyone know?

I’m sure it will work fine. It should say something like water, fuel and oil. Teflon will work with oil.

oosik · Jan 19, 2019

Can't tell 'dogs. What does it say on the back of the tube? Pretty sure teflon type will work with most all oil products, Besides - if it's the only sealant they sold - what have you got to loose. Try it. If it works - great. If not - keep looking.

WranglerX · Jan 19, 2019

Read instructions on container..... This is my go to.. Use it on most everything....

Not a fan of PTFE tape always ends up a problem for me...

Dale

Langanobob · Jan 20, 2019

I sometimes just use Permatex #2 gasket sealer. Never had a problem with it.

Gary Fowler · Jan 20, 2019

Most hydraulic fittings are tubing type with male/female connections or O-ring seal. The threads just hold the connection tight. Thread lubricant (it is never a sealant when the threads are made up properly) is used to lubricate the joint so the proper torque can be applied without stripping or galling the threads. If the threads are made up correctly, then regular grease could be used. Some products called thread sealant just fill in the gaps on improperly made threads and lubricate the threads so they glide smoothly to the point of tightening and therefore may or may not seal the joint and prevent leaks.

SAE pipe threads (and any other threads) can be tightened to the point of deforming the threads which can cause leaks with or without using thread sealant. In my career as a Quality Manager and Inspector, I have seen more threaded joints leaking from overtightening than any other cause.

LD1 · Jan 23, 2019

Get a bottle of loctite 545 and be done.

sixdogs · Jan 23, 2019

I'm removing the loader fittings that go from the boom to the junction box ( when you remove the loader) and replacing that box with a quick disconnect version--Kubota M7040. Ho much torque do I use to tighten hydraulic fittings? Others here said to not overtorque so any questimates on how tight to screw the hoses and into fittings and then the fittings to the box?

LD1 · Jan 23, 2019

I am sure there is torque specs out there somewhere.

I just go as tight as I would with a standard wrench, if it was on a bolt instead of a fitting. Just kinda a feel thing.

WranglerX · Jan 23, 2019

How tight?... Just tight enough it does not leak..... If you break/damage the fitting or round off the hex portion and it sill leaks it is a bad fitting or "O" rings ( or sealing washers) and no amount of force will fix situation.... Experience is best for applying proper toque... Listen to little voice in back of head that says "it may be tight enough"...

Dale

radios1 · Jan 23, 2019

RNeumann said:
I知 sure it will work fine. It should say something like water, fuel and oil. Teflon will work with oil.

I used teflon tape on the fuel lines on my oil burner, the teflon disintegrated quickly, I think a week!. and that's a low pressure use.. I now only use pipe dope for oil.. chlorine, as used in cutting fluid, is murder on teflon too, I machined 100 teflon parts, only to find out the next day, that they swelled up,(it took a bit of time)..

WranglerX · Jan 23, 2019

Something to read if interested.....

Thread seal tape - Wikipedia

Dale

sixdogs · Jan 23, 2019

Good advice. I know how tight most things should feel so I'll go with that. It is kind of a feel thing.

bcp · Jan 23, 2019

RNeumann said:
CAN OF WORMS OPENED!

That doesn't work very well either. They often crawl out of or farther into the fitting before it is screwed together.

Bruce