Tape on hydraulic connections?

[acme97]

I just ordered a hydraulic top link and the hoses. My question is do I need to put tape on the male connector before attaching to cylinder? If so, what kind? Will standard teflon plumbing tape work?
Thanks

 

[J_J]

Some people use tape, and others use paste. There are some on here that say never use tape, but if you stay one or two threads you should be safe enough to use tape. It is your choice..

 

[Reg]

I just ordered a hydraulic top link and the hoses. My question is do I need to put tape on the male connector before attaching to cylinder? If so, what kind? Will standard teflon plumbing tape work?
Thanks

I don't know the particular fittings you will be using, but GENERALLY they are flared to match each other and the threads merely pull those surfaces together - i.e. the threads themselves are NOT where the seal is made.
About the only "purpose" it serves is to lubricate the threads, so you will get a little more clamping force for any given amount of tightening torque.
There may be SOME corrosion protection, though I doubt that it is meaningful.

I have used tape, I have never had it result in a problem, but I have given up using it.
You may be better and more careful than I am, but there is always a CHANCE that someone else will take it apart at some point and little bits of tape debris will get into the hydraulic system.

SUMMARY: You don't need it, it doesn't "seal", there COULD be problems with it later on.

 

[J_J]

If the fittings are NPT he will need something.

https://www.surpluscenter.com/item.asp?item=9-5196&catname=hydraulic

 

[Chilly807]

Some people use tape, and others use paste. There are some on here that say never use tape, but if you stay one or two threads you should be safe enough to use tape. It is your choice..

+1

Leave a couple threads at the male end free of tape. Looking at the free end of the male fitting, wind the tape around it clockwise.

Sean

 

[kennyd]

Lots of threads on this, and equally lots of debate. If you search the term "PTFE" you can read for hours.

I am in the "no tape" camp, prefer a quality PTFE paste that's rated for hydraulic use. But-depending on what fittings you have you may need nothing, NPT threads are the only ones that need a sealant.

 

[acme97]

Thanks for all the advice. I just put the hoses on the cylinder. Decided to not use tape. Of course if it leaks then I might have to reconsider. Now only 20 more days until I pick up the new baby!

 

[beenthere]

I have mostly used tape (male npt), but lately have switched to only paste. Less possible problem, I guess, with paste and a neater look too.

 

[J_J]

Thanks for all the advice. I just put the hoses on the cylinder. Decided to not use tape. Of course if it leaks then I might have to reconsider. Now only 20 more days until I pick up the new baby!

You need to consider the fact that NPT is designed to compress the threads together, and relies on something to fill the small voids. You normally always use something on NPT threads. Also, NPT was not designed to install and remove over and over. One or two times compressing the threads is about the limit.

 

[Chilly807]

You need to consider the fact that NPT is designed to compress the threads together, and relies on something to fill the small voids. You normally always use something on NPT threads. Also, NPT was not designed to install and remove over and over. One or two times compressing the threads is about the limit.

Just by using a thread sealant you actually protect the tapered threads by providing both a lubricant and sealing agent in one. You may get twice the number of re-uses or more.

Sean

 

[J_J]

Yes, I agree, and most people keep using them until they leak to much.

 

[moose13]

I have never had much luck with the paste. Maybe its me but i recently built a splitter and tried paste only from what i have read here. I had three leaks. I removed them cleaned the piece and taped. Fixed the leak and good to go. I think people use too much tape. Clockwise and about two wraps. Any more and the threads will just push the tape out of the way and not seal a thing.

We are talking NPT

 

[J_J]

How many times have you used that NPT fitting?

 

[MtnViewRanch]

When I added 2 rear remotes to my Mahindra 3215, I had all new hose and pipe fittings from Discount Hydraulic Hose. I used Teflon paste from DHH. I had 3 leaks at the various pipe thread fittings. I took stuff that needed to be taken apart and resealed with 3 wraps of Teflon tape, NO more leaks. :thumbsup: A lot of people say how careful you need to be with Teflon tape and how it can get into the hydraulic system one way or another. No one has ever said anything about what happens when you take apart a fitting that has had Teflon paste put on it, and how hard it can be to even get it apart. What a nightmare. Little chunks of hard paste to deal with and to be very careful not to get into the system. Give me Teflon tape any day. As long as you are careful as to where and how the tape is put on, there should be zero problems using tape. For me, it is waaaaay easier to clean old tape off of and out of a fitting than it is to clean the old Teflon paste.

Maybe it is just me, but that has been my past experience.

 

[mmurphy]

:thumbsup::thumbsup:


I have to add to what JJ is getting at about how many times NPT fitting used. It is not as much as threads worn, as how the fitting gets distorted and out of round. At that point, then no tape, or paste will prevent leaks.:2cents:

 

[RickB]

Finally a concise thread (no pun intended) about the use of different sealants that provides accurate information AND the different trains of thought on the topic.

We all agree that tapered threads require sealant, flare, ORF and ORB styles do not.

 

[MHarryE]

For a period of time we had a problem with leaking HMU (hand metering units, the hydrualic steering control). After replacing over a dozen units, we had some disassembled and found small pieces of foreign material between the seal and shaft. Using a mass spectrometer, we determined the material was Teflon based. We used only ORB, ORFS, and split flange flittings - where could Teflon come from? We discovered we did have NPT threads - the strainers on the outlets of the reservoir where the 2 pump inlets attach. Somebody had changed from Loctite Hydraulic Sealant to Teflon tape (Lotite sealant is $$$) and the bits of Teflon tape were making their way to the shaft seal. Just another reason I always have a small bottle of blue Loctite sitting around.

 

[whistlepig]

I use Loctite 567. Threadlockers, Thread Sealers, Gasketing, Retaining. Loctiteｮ Anaerobic Adhesives For Professionals.

 

[pat32rf]

I've NEVER had Teflon paste (Loctite) harden the way regular plumbers "dope" does.
Unless its NPT most of my joints just get a bit of hydraulic fluid on them as they are being assembled....

 

[J_J]

You guys that use Loctite 567, did you realize that a cure time of 72 hrs was required for 50% strength, and if you applied an activator, the cure time was 100 % in 24 hrs. Do you go ahead and apply pressure to the fittings before that time.