Using PTFE tape or Teflon tape on metal fuel line fittings?

[Supercharged111]

I quit with thread tape years ago on cars. I use Permatex thread sealant now.

 

[thinger2]

Okay here we go. Torch me later.
A "Gas" under pressure always wants to escape to atmosphere.
Nature just hates al low pressure and compensates.
Wind is a good example.
High to low.
A liquid cant be compressed, You cannot compress oil or water in its normal state.
What happens with an air leak on a fuel system or a hydrualic system is the introduction of air foams that fluid and causes a loss of pressure because the normal chemical bond of that fluid has been disturbed by the influx of Oxygen
And oxygen wants to vent.
As all gases do
And that foamy gas has to go someplace.
Usually through the seals and when the gas burps, and the hydraulic fluid cools , It pulls in moisture from the air to compensate for the pressure/temperature differential
Which doesnt mean not a damn thing but by god Ive waiting for that to come up in trivial pursuit
And I know that has nothing to do with anything at all.
But, My Wife wants to know If im gonna go to friggen Walmart with her mother tonight.
I would, but Im online helping somebody who really needs it.
Its all a big damn community fer ***** sake.
Post more! That is a pretty cool project.
I really am interested to see where you take this thing

 

[Schurkey]

I picked up some fuel line rated tape at lowes to prevent leaks on my harbor freight fuel pressure guage. It worked well. Right next to the regular plumbers tape, but it's yellow. Make sure it's only on the threads, you don't want anything getting pulled into the filter and plugging it up.

Working in plumbing we use monster blue teflon tape. Also grey one is good as well. Says it's good for a lot of chemicals and fuel.

White is cheap and yellow was for lp or gas. We also had pink but never used it since the grey and blue was professional and covered all we needed it for

But, keep this in mind. "Gas Rated Thread Tape" has nothing to do with gasoline or any normally liquid fuel.
It only applies to actual "gas" like Propane.

White...yellow...blue...grey...plaid...infra-red...ultra-violet...MAKES NO DIFFERENCE.

The **** is all the same--PTFE is Teflon but without the DuPont brand name. It's all resistant to the same chemicals. There's two differences, and neither one is important.

1. Some tape has a colored dye put into it. The stupid color becomes a registered trade-mark that no one else can use.

2. Some tape is thicker than others. Saves two seconds of winding more tape onto the threaded fitting.

ALL of those Teflon/PTFE thread tapes are a friggin' disaster. If it doesn't shred when you screw the thing together, it'll shred when you take it apart. All the little strings of shredded tape then contaminate the system. The best--and perhaps only acceptable use of thread tape is on pre-threaded iron pipe for compressed gasses--fuel gasses or merely compressed air. The Chinese pre-threaded pipe and fittings are threaded so rough that a typical liquid sealer can't fill the enormous gaps between the threads. Not a big surprise that the leading retailers of pipe tape source their product from the same country building the defective pipe!

And forget about plumbing tape entirely... ...Tape? no nope never

I quit with thread tape years ago on cars. I use Permatex thread sealant now.

TRUTH! Teflon/PTFE tape has NO business on an automobile, ESPECIALLY in the fuel system or oil system.

But "Permatex" makes many different formulations of "thread sealant", and at least one of them is pretty pathetic--the common one sold in a brush-top plastic tub.

You're looking for the "PST" versions, #565, #567, and/or #592. 592 is the easiest to source, and not as expensive as 567. VERY recommended. Sold as "Loctite" or "Permatex" depending on the market.

 

[Hipster]

Get the right fittings.

If it lets loose and sprays fuel and burns your ride down you won't have the opportunity to figure out why the fittings weren't sealing. In general, figure out why it's not sealing. Damaged flare on the male end, damaged female/inverted flare on the receiving end. Npt threads buggered up, damaged o-ring or whatever the case may be but you shouldn't need tape or goop to get it to seal. I never depend on these type of products to seal 1200psi of brake line pressure either.

The $28 one (or the one that came off?) could be shortened and reflared or what ever the opposite end is by a hydraulics shop and some Napa's make up hydraulic, fuel, and oil lines.

 

[thinger2]

Yep, tape is bad.
But, more importantly, before you burn down home depot in a fit of rage,
take a look at how different types of pipe and tube and fittings work.
Some types like "NPT" are a tapered thread and are cut very differently than other types of thread.
Some types of thread are designed specifically for the use of thread tape.
Others are designed to never use thread tape.
Most of the time people jyst crank a buch of random **** together with no idea about the difference between thread types and then pack that **** full of tape
and blame the tape.
Kinda like my Ex, just cuz it screws together dont mean it goes together.
Do some deep Google save yerself some leaks
They are threaded in differdnt ways and thd ID/OD are measured in different ways.
This also applies to the difference between "pipe" and " tube"
This is why 1" pipe is not 1" in diameter,
but 1 " tube is 1" inch diameter.
Its all a bit of arcane nuttiness but well worth the look.
Understanding pipe sizes and thread types will really cut down on aggravation for the rest of your life.
And will allow you to go to Home Disaster or Blows, grab yer **** and get the hell out.
They should teach it in school

 

[thinger2]

White...yellow...blue...grey...plaid...infra-red...ultra-violet...MAKES NO DIFFERENCE.

The **** is all the same--PTFE is Teflon but without the DuPont brand name. It's all resistant to the same chemicals. There's two differences, and neither one is important.

1. Some tape has a colored dye put into it. The stupid color becomes a registered trade-mark that no one else can use.

2. Some tape is thicker than others. Saves two seconds of winding more tape onto the threaded fitting.

ALL of those Teflon/PTFE thread tapes are a friggin' disaster. If it doesn't shred when you screw the thing together, it'll shred when you take it apart. All the little strings of shredded tape then contaminate the system. The best--and perhaps only acceptable use of thread tape is on pre-threaded iron pipe for compressed gasses--fuel gasses or merely compressed air. The Chinese pre-threaded pipe and fittings are threaded so rough that a typical liquid sealer can't fill the enormous gaps between the threads. Not a big surprise that the leading retailers of pipe tape source their product from the same country building the defective pipe!



TRUTH! Teflon/PTFE tape has NO business on an automobile, ESPECIALLY in the fuel system or oil system.

But "Permatex" makes many different formulations of "thread sealant", and at least one of them is pretty pathetic--the common one sold in a brush-top plastic tub.

You're looking for the "PST" versions, #565, #567, and/or #592. 592 is the easiest to source, and not as expensive as 567. VERY recommended. Sold as "Loctite" or "Permatex" depending on the market.

I think people dont really understand how durable teflon tape is and how far it will stretch while still making its way through your oiling system.
And the damage it can do if it plugs a galley or ends up in a main or a lifter.
Ive pulled pcv valves that were wrapped in 40 feet of tape because they didnt want to spend 6 bucks for a grommet
Power steering hoses, oil pressure lines
Brake lines fer gods sake.
Because they decided to do it the right way instead of using electrical tape like some kinda dumbass

 

[SUBURBAN5]

Yep, tape is bad.
But, more importantly, before you burn down home depot in a fit of rage,
take a look at how different types of pipe and tube and fittings work.
Some types like "NPT" are a tapered thread and are cut very differently than other types of thread.
Some types of thread are designed specifically for the use of thread tape.
Others are designed to never use thread tape.
Most of the time people jyst crank a buch of random **** together with no idea about the difference between thread types and then pack that **** full of tape
and blame the tape.
Kinda like my Ex, just cuz it screws together dont mean it goes together.
Do some deep Google save yerself some leaks
They are threaded in differdnt ways and thd ID/OD are measured in different ways.
This also applies to the difference between "pipe" and " tube"
This is why 1" pipe is not 1" in diameter,
but 1 " tube is 1" inch diameter.
Its all a bit of arcane nuttiness but well worth the look.
Understanding pipe sizes and thread types will really cut down on aggravation for the rest of your life.
And will allow you to go to Home Disaster or Blows, grab yer **** and get the hell out.
They should teach it in school

Rings a bell lol. ID and OD was big for us with copper

 

[drumsdaddy]

I agree with the fellers about Teflon tape shearing off on threads. I’ve been in the natural gas field for 47 years and we use pipe dope on ALL threaded fittings. Key Tite is the brand we use. Heavy, oily and doesn’t dry out. You have to go to a plumbing store to get it. Big box stores don’t carry it.
Teflon pipe dope leaks...trust me.
Had a truck in the shop 30 years ago and the hydraulic pump was shaking like a dog passing a peach seed. One of our Walmart graduates used a bunch of Teflon tape everywhere and it ended up in the orifices of the hydraulic system. It was a cluster phuck to remove.
Don’t use it on autos and plumbing...not worth the headache.

 

[454cid]

I've never liked the tape, and only use it for very temporary connections. I've got pipe dope that I would use instead....I think it's still teflon but mixed with an oil or something.

I've not used either in place of an o-ring or to fix a bad flare that I can recall. Thankfully when I've had something like a cooler line leaking I've been able to tighten it up enough to stop the leak.

 

[evilunclegrimace]

I can't find a M16X1.5 Male or female to barb that come with an "o ring seal", other than female pair at Leroy Diesel which is $28 after shipping. I need one female and one male. This is to be used behind fuel filter only (at LP) on a 6.5l K3500. Could these tapes be used as a substitute? The goal is to avoid leaks.

Found Them!!! S.U.R.& R. auto parts at Summit racing K270 (5/16") and K275 (3/8").