Teflon Tape or Teflon Paste

[mjonesnh]

Blew a power steering hose on my New Holland TC34DA today, not a complete blow out but a split about 1" long. Tractor has 2 rubber hoses about 12" long that goes from metal pipe to the power steering cylinder at left wheel. Decided to replace both hoses while I am at it. Ordered them from local New Holland dealer and should be here Wed. or thur.. When I install the new hoses should I use Teflon tape or the Teflon paste. Have been told by some to use tape, some have advised to use paste as the tape has a tendency to get inside the cylinders,and a couple of people have stated to not use either just the bare fittings. What is the consensus on this forum?

 

[LD1]

Tape is not reccomended for hydraulics. Paste is or a liquid type sealer. I know loctite makes one thats purple and designed for hydraulics.

That said, what kind of fittings are they. If JIC flare or NPSM, no sealer is required as the seal is mechanical. And if it is an ORB fitting, again, no sealer as the o-ring seals the fitting.

 

[RickB]

I have used tape successfully and professionally for decades. Used properly, teflon tape is safe and effective, period.
Used carelessly and improperly, teflon tape can cause problems when allowed to migrate within the system.
Your call.

 

[JoeBuyer]

I use the Loctite
http://www.henkelna.com/us/content_data/141299_LT5557_5452SSF448695.pdf

 

[RickB]

I use the Loctite

Loctite is a brand name. It would be helpful if you posted which Loctite product you prefer.

 

[EddieWalker]

Hydralic lines are not like water lines. They are under such pressure that you cannot seal the threads like you can water lines. The seal has to be metal to metal or with a rubber seal like an o ring. It really depends on what you have and how much pressure you are dealing with to know what type of fittings you use.

Eddie

 

[mjonesnh]

Believe one end is flare nut, the end that couples to the metal pipe but the end that screws to the hyd cyl. looks just like plain 3/8 npt. Looks like I will have to break flare nut loose and then just un-screw the hose from cyl. as the nut has 9/16 flats that seem to be integral with the with crimped end. Forgive me for my limited fitting knowledge as this this the first hose I have ever had to replace.

 

[JoeBuyer]

Loctite is a brand name. It would be helpful if you posted which Loctite product you prefer.

Sorry, just updated it
http://www.henkelna.com/us/content_data/141299_LT5557_5452SSF448695.pdf

 

[Soundguy]

taper threads usually need sealant as mentioned above. paste or liquid.. or tape. I don't usually prefer tape.. but if used correctly as rick mentions, it's fine.. just roll it correct direction.. and as with paste.. keep it off the first full thread. There are some new -er taper threads that seal much better than NPT.. still....

compression fittings and flare fittings do not need thread sealant as the threads are not sealing.. it is the metal face contact. Similarly, ORF and ORB fittings do not need thread sealant.

 

[chopped]

Ive alwasy thought one purpose of teflon tape was to also make it removed easier in the future.(like 30 years ). Is that also true.?

 

[RobertBrown]

Hydralic lines are not like water lines. They are under such pressure that you cannot seal the threads like you can water lines. The seal has to be metal to metal or with a rubber seal like an o ring. It really depends on what you have and how much pressure you are dealing with to know what type of fittings you use.

Eddie

He's right......again

 

[RobertBrown]

Ive alwasy thought one purpose of teflon tape was to also make it removed easier in the future.(like 30 years ). Is that also true.?

Teflon/pipe dope/tape prevents the threads from locking before they seat. This lubricant allows you to pull the joint tighter than without.
Neverseize is what you would use to prevent a locked threaded joint, not necessarily a pipe joint.

 

[RickB]

Hydralic lines are not like water lines. They are under such pressure that you cannot seal the threads like you can water lines. The seal has to be metal to metal or with a rubber seal like an o ring. It really depends on what you have and how much pressure you are dealing with to know what type of fittings you use.

Eddie

Tapered pipe threads require a sealant in instances where the threads form the sealing surfaces. Doesn't matter which fluid is being contained.

 

[Soundguy]

ntpf or dryseal was that other variant I was thinking of.

eliminates spiral leakage around the deforemed thread flank/root...

 

[lutt]

Sof-set is a good one, we use it on our steering system here at work,but also on everything else that is pipe to pipe. I have used teflon tape for 20 years out here and on the farm on hydraulics,high pressure air,water, lube oil lines,and fuel lines with success. But sof-set is better,easier to use. Just always make sure your fittings are clean, I even wire wheel new steel pipe fittings, the only ones I dont are aeroquip,but I still make sure they are clean. Also sof-set has anti-seize for later down the road when you want to take it back apart. LUTT

 

[Scooby074]

Assuming its pipe thread, my advise is to go with Loctite 592 (paste). While tape can be used, paste is MUCH safer.

 

[Mace Canute]

The Path to a Leak-Free Hydraulic System

http://www.sbp.noaa.gov/resources/engineering/docs/Hydraulic_Systems_Leak_Free.pdf

 

[sixdogs]

The Path to a Leak-Free Hydraulic System

http://www.sbp.noaa.gov/resources/engineering/docs/Hydraulic_Systems_Leak_Free.pdf

Good site and informative thread. So can we assume that the Loctite prduct has none of the little pieces that might break free and bother a hydraulic system? Up until yesterday I used teflon tape but as soon as I can get some of the Loctite product I think I'm done with tape forever.

 

[J_J]

Here is what Loctite recommends for paste and primer..

Loctite®
Fast
Cure 5452™
1265769 50 ml tube
Purple
29,000/200,000
thixotropic
-65°F to
300°F (-54°C
to 149°C)
10,000
7088™
QuickStix™
Primer,
7649™
Primer N™
or
7471™
Primer T™
1265770 250 ml tube
NE

Teflon tape has been banned in a lot of places, so use at your own risk.

And yes, I will use it if it is all I have at the moment.

Main problem is cleaning out all the old tape from the threads, and the fact that NPT fittings should not be used and re-tighten many times.

 

[JoeBuyer]

Since using the red Loctite I have not had a problem. I use the liquid type and make sure I let it cure before using.