Author Topic: oil pressure switch replacement- teflon tape?  (Read 19345 times)

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Offline excellrec

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Re: oil pressure switch replacement- teflon tape?
« Reply #25 on: July 10, 2013, 01:41:52 pm »
Speaking of these, does anyone know off hand what the diameter and thread pitch is?  I have been meaning to replace my unused one with an oil temp sensor.

1/8"/27 pipe thread.
 Just get one with a 1/8" pipe thread, it's a pretty standard size.

Hmm, the closest Trailtech has is a 1/8 - 28th BSPP.. which I presume won't Jibe with the 1/8" 27. 

http://www.trailtech.net/V300-003.html

Plus, it looks like the lead would bottom out in there pretty quick, guess I'll look for an adapter for their smaller sensor-

http://www.trailtech.net/V300-001.html

Offline Powderman

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Re: oil pressure switch replacement- teflon tape?
« Reply #26 on: July 10, 2013, 01:49:09 pm »
BSPP is a British Standard Pipe Parallel Thread. Basically a machine thread used for interconnecting and sealing pipe ends by mating an external (male) with an internal (female) thread and has been adopted as a standard scale used in plumbing fittings, except in the United States where NPT is the standard used.
So yes, it is completely different type thread than what is on the Honda oil pressure switch.
TT's water temp sensor is intended to go into an open water line and not into a pressure feed line like an oil pressure switch.
you need an inline fitting like this for that sensor:
http://www.trailtech.net/7500-3041.html
« Last Edit: July 10, 2013, 01:53:46 pm by Powderman »

Offline excellrec

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Re: oil pressure switch replacement- teflon tape?
« Reply #27 on: July 10, 2013, 02:09:01 pm »
BSPP is a British Standard Pipe Parallel Thread. Basically a machine thread used for interconnecting and sealing pipe ends by mating an external (male) with an internal (female) thread and has been adopted as a standard scale used in plumbing fittings, except in the United States where NPT is the standard used.
So yes, it is completely different type thread than what is on the Honda oil pressure switch.
TT's water temp sensor is intended to go into an open water line and not into a pressure feed line like an oil pressure switch.
you need an inline fitting like this for that sensor:
http://www.trailtech.net/7500-3041.html

I was thinking it might not work with oil too but they make adapters to use them as oil temp sensors as well (e.g. VA-12150) so that's where I got the idea to get an adapter to go from M6x1.0 to 1/8-27.

Offline Powderman

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Re: oil pressure switch replacement- teflon tape?
« Reply #28 on: July 10, 2013, 04:00:29 pm »
BSPP is a British Standard Pipe Parallel Thread. Basically a machine thread used for interconnecting and sealing pipe ends by mating an external (male) with an internal (female) thread and has been adopted as a standard scale used in plumbing fittings, except in the United States where NPT is the standard used.
So yes, it is completely different type thread than what is on the Honda oil pressure switch.
TT's water temp sensor is intended to go into an open water line and not into a pressure feed line like an oil pressure switch.
you need an inline fitting like this for that sensor:
http://www.trailtech.net/7500-3041.html

I was thinking it might not work with oil too but they make adapters to use them as oil temp sensors as well (e.g. VA-12150) so that's where I got the idea to get an adapter to go from M6x1.0 to 1/8-27.

The VA-12150 has a M12x1.5 thread. You'll have to find somewhere that has oil and a hole that size in order to use an oil temp sender like that. I understand what you want to do but it may not be feasible in your situation.
That oil sender is designed to have oil flowing past it not just pressurized oil at the end of the sending unit.
I have a Trail Tech Vapor on my race bike and researched exactly what you are attempting and couldn't make it work on mine.
« Last Edit: July 10, 2013, 04:05:01 pm by Powderman »

Offline kghost

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Re: oil pressure switch replacement- teflon tape?
« Reply #29 on: July 10, 2013, 04:16:41 pm »
Just a quick word of instruction.......

Teflon tape is used to get the pipe fitting further into its bore......

It's not designed to seal.

" The use of PTFE tape in tapered pipe threads performs a lubricating function, which more easily allows the threads to be screwed together, to the point of deformation, which is what creates the seal."

http://en.wikipedia.org/wiki/Thread_seal_tape

If you read the wiki post further you would have seen that it is commonly used as a thread sealer.

Teflon is a brand name and Teflon does not make a Teflon Thread Sealer tape. Most time Teflon tape refers to common PTFE thread sealing tape specifically made for sealing threads.

Maybe we are saying the same thing maybe not...........

If you are installing a tapered thread.....what seals is the interference fit between the threads. Not the Teflon or PTFE. That is why they are tapered.

The Teflon just facilitates the seal.

Flared fittings are different then tapered pipe thread of any standard.

If you don't believe this....do your research.

Stranger in a strange land

Offline Powderman

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Re: oil pressure switch replacement- teflon tape?
« Reply #30 on: July 10, 2013, 04:25:04 pm »
I agree that the way a pipe thread (tapered) works it should seal without the need of any sealant. To say that Teflon thread sealer is not a sealer but a lubricant only is completely false.

Offline kghost

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Re: oil pressure switch replacement- teflon tape?
« Reply #31 on: July 10, 2013, 06:21:57 pm »
I agree that the way a pipe thread (tapered) works it should seal without the need of any sealant. To say that Teflon thread sealer is not a sealer but a lubricant only is completely false.

You would be wrong. Very wrong.

The threads cut on the pipe will not match what it's threaded into exactly.

Different manufacturers, different dies, different die wear, different machines different tolerances etc.....mean that the threads on one piece are not exact to any other.

Teflon tape is used to reduce friction and metal to metal galling during the installation.

Brass, steel, aluminium. Dissimilar metals the friction level during installation rises rapidly when threaded together.

Most plumbing tests have a question. "Is Teflon tape a sealer or a lubricant?" If you say sealer you'll get it wrong.

When I went to engineering school there was a similar question.


Teflon btw is Polytetrafluoroethylene. It's a lubricant. Has one of the lowest coefficient of friction of any solid.

It is NOT a sealant.
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Offline Powderman

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Re: oil pressure switch replacement- teflon tape?
« Reply #32 on: July 10, 2013, 06:38:13 pm »
I agree that the way a pipe thread (tapered) works it should seal without the need of any sealant. To say that Teflon thread sealer is not a sealer but a lubricant only is completely false.

You would be wrong. Very wrong.

The threads cut on the pipe will not match what it's threaded into exactly.

Different manufacturers, different dies, different die wear, different machines different tolerances etc.....mean that the threads on one piece are not exact to any other.

Teflon tape is used to reduce friction and metal to metal galling during the installation.

Brass, steel, aluminium. Dissimilar metals the friction level during installation rises rapidly when threaded together.

Most plumbing tests have a question. "Is Teflon tape a sealer or a lubricant?" If you say sealer you'll get it wrong.

When I went to engineering school there was a similar question.


Teflon btw is Polytetrafluoroethylene. It's a lubricant. Has one of the lowest coefficient of friction of any solid.

It is NOT a sealant.

If you answered a lubricant or a sealer you would be wrong on both counts because there is no such thing as Teflon tape. First of all Teflon is a brand name and they do not make a Teflon tape. I have been talking about Teflon TFE paste is a pipe sealant and lubricant. If you read my posts you will not find that I ever said Teflon tape is a sealer or did I recommend using it. Do some more research before telling me I'm wrong again.

Offline kghost

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Re: oil pressure switch replacement- teflon tape?
« Reply #33 on: July 10, 2013, 06:51:51 pm »
TFE paste........made with Polytetrafluoroethylene PTFE

Teflon is a Dupont registered name for PTFE.

It's a lubricant.

What's commonly referred to as "Teflon tape" isn't made by dupont but it does contain PTFE.

PTFE is resistant to van der waal forces and geckos can't stick to it.

I will quit saying your wrong if you quit calling PTFE's a sealer.

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Offline Powderman

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Re: oil pressure switch replacement- teflon tape?
« Reply #34 on: July 10, 2013, 07:11:55 pm »


You're right and Dupont is wrong. I never said PTFE was a sealer. I said Teflon Pipe Sealer Paste is a sealer. The fact that is has PTFE in it as a lubricant doesn't mean that the other ingredients in it don't make the product a pipe sealer. Show me once where I said PTFE is a sealer.

Offline kghost

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Re: oil pressure switch replacement- teflon tape?
« Reply #35 on: July 10, 2013, 07:22:38 pm »
Sometimes it's best to raise your hand and say......" I did not know that"

You're welcome to keep arguing.....
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Offline Powderman

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Re: oil pressure switch replacement- teflon tape?
« Reply #36 on: July 10, 2013, 07:35:37 pm »
So, you're raising your hand then. You haven't proven me wrong though you have said so more than once and, as George Carlin once said:
"Never argue with an idiot; they'll drag you down to their level, and beat you with experience."

Offline kghost

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Re: oil pressure switch replacement- teflon tape?
« Reply #37 on: July 10, 2013, 08:03:41 pm »
Just a quick word of instruction.......

Teflon tape is used to get the pipe fitting further into its bore......

It's not designed to seal.

" The use of PTFE tape in tapered pipe threads performs a lubricating function, which more easily allows the threads to be screwed together, to the point of deformation, which is what creates the seal."

http://en.wikipedia.org/wiki/Thread_seal_tape

If you read the wiki post further you would have seen that it is commonly used as a thread sealer.

Teflon is a brand name and Teflon does not make a Teflon Thread Sealer tape. Most time Teflon tape refers to common PTFE thread sealing tape specifically made for sealing threads.

You said it right there....tape.

Suddenly your all about the paste.

PTFE is a lubricant.
Stranger in a strange land

Offline Powderman

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Re: oil pressure switch replacement- teflon tape?
« Reply #38 on: July 10, 2013, 08:07:07 pm »
Not suddenly, I was all about paste in my very first post, go back and read it.

Offline kghost

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Re: oil pressure switch replacement- teflon tape?
« Reply #39 on: July 10, 2013, 08:08:57 pm »
You keep wanting to talk about sealer.....

Use sealer if you like. If your talking about sealer with teflon....the teflon PTFE it's in there for a lubricant.

As we were taking about a tapered thread on an oil pressure sender......it should be seal via the thread. Not with sealant  if you use teflon tape you are using it for lubrication. It doesn't need sealant it need lubrication. It's the nature of the design.
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Offline 23tbucket

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Re: oil pressure switch replacement- teflon tape?
« Reply #40 on: July 10, 2013, 08:21:25 pm »
The sender threads on all Japanese bikes (including Honda) are 1/8" BSPT...NOT 1/8" NPT.....

Offline Powderman

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Re: oil pressure switch replacement- teflon tape?
« Reply #41 on: July 10, 2013, 08:28:02 pm »
The sender threads on all Japanese bikes (including Honda) are 1/8" BSPT...NOT 1/8" NPT.....

I'll raise my hand and say "I did not know that"
NPT/NPS threads have a 60° included angle and have flattened peaks and valleys ; BSPT threads have a 55° included angle and have rounded peaks and valleys.

Offline andrewk

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Re: oil pressure switch replacement- teflon tape?
« Reply #42 on: July 10, 2013, 10:04:05 pm »
Yeah, so you can jam one in there and make it work, but better not try to replace it with an OEM one down the road.  Or, maybe with enough goop on it, it will still seal.

Waste of time with sealing the pressure sensor anyway, I only ever see them leak from the top cap.

Offline HondaMan

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Re: oil pressure switch replacement- teflon tape?
« Reply #43 on: July 10, 2013, 10:57:24 pm »
The oil pressure switch needs a reliable ground path to function electrically, that ground path is the threads on the switch and the mating threads in the engine, and so covering those threads with tape, paste, etc. is not recommended.  Typically, nothing extra is required to prevent leaks at the oil pressure switch.

What he said...^^

Your light may not work if you use tape.
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Offline CoachDoc

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Re: oil pressure switch replacement- teflon tape?
« Reply #44 on: July 10, 2013, 11:38:46 pm »
New OEM switch installed. No tape.....it became clear from reading all these posts that the threads make the seal. Those who said the leak is always from the workings of the switch itself undoubtedly are 100% correct. I did have some trouble getting the original switch out after sitting in those threads for almost 40 years, had to resort to heat to free it up. After rebuilding my starter switch and fixing this leak, bike is 100% again, so I am a very happy camper.





Offline wardenerd

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Re: oil pressure switch replacement- teflon tape?
« Reply #45 on: July 11, 2013, 04:46:07 am »
My pressure sensor is leaking from the sensor and not the threads.  Can I tilt the
bike somehow to change this without oil leaking out.  I just changed the oil and I do not want to do that agin this fast or make a huge mess.

Offline Dave Voss

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Re: oil pressure switch replacement- teflon tape?
« Reply #46 on: July 11, 2013, 07:32:13 am »
My pressure sensor is leaking from the sensor and not the threads.  Can I tilt the
bike somehow to change this without oil leaking out.  I just changed the oil and I do not want to do that agin this fast or make a huge mess.

The location of the oil pressure switch is high enough to not loose much oil when removed, especially if the motorcycle is on the centerstand.  Loosen the existing switch, leaving the last thread or two engaged, and have the replacement switch handy, so that you can quickly swap them, which only takes a few seconds.
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Offline crazypj

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Re: oil pressure switch replacement- teflon tape?
« Reply #47 on: July 11, 2013, 09:30:37 am »
I doubt you'll lose even a teaspoon of oil changing switch (unless you try and do it with engine running  ;D)
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Offline CoachDoc

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Re: oil pressure switch replacement- teflon tape?
« Reply #48 on: July 11, 2013, 11:57:04 am »
I did the change with the bike on the center stand. Lost no oil whatsoever, and several minutes elapsed between removal of the old switch and the install of the replacement.