The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 11-03-2018, 01:04 PM   #26
68Gold/white
Registered User
 
Join Date: Sep 2011
Location: Ark City, Kansas
Posts: 3,272
Re: Best fuel line thread sealant?

Quote:
Originally Posted by HIGHWAY BY THE SEA View Post
Here is what I was using. It looks uncannily similar to what is pictured in that link.
I ended up doing what I said with cutting the old metal line end and splicing it with the rubber hose (temporarily).


Oh well...I went to parts store, they did not have what I was looking for...

If you look inside the carb fitting, some of the inverted seats in the inlet nuts were smaller than one would think.

I believe (as others have stated...) that the taper on the fitting you installed, and inverted seat are not touching to make a seal.

You MIGHT be able to grind the end of the threads down (make the end flat)some to make those 2 pieces meet...the might part is some what iffy. I believe your new fitting is made of steel ( a magnet will tell). It may not mate together with the inverted seat in the carb fitting.......

The steel tubing works better because the flared end inside the nut is some what soft and pliable, allowing the inverted seal...so thatm,ight be your only way to go, for a while. Using 2 clamps is a good idea, I usually always use 2 clamps. if possible...
68Gold/white is offline   Reply With Quote
Old 11-03-2018, 01:51 PM   #27
HIGHWAY BY THE SEA
Registered User
 
HIGHWAY BY THE SEA's Avatar
 
Join Date: Nov 2012
Location: BY THE CAROLINA SEA
Posts: 917
Re: Best fuel line thread sealant?

Quote:
Originally Posted by 68Gold/white View Post
Oh well...I went to parts store, they did not have what I was looking for...

If you look inside the carb fitting, some of the inverted seats in the inlet nuts were smaller than one would think.

I believe (as others have stated...) that the taper on the fitting you installed, and inverted seat are not touching to make a seal.

You MIGHT be able to grind the end of the threads down (make the end flat)some to make those 2 pieces meet...the might part is some what iffy. I believe your new fitting is made of steel ( a magnet will tell). It may not mate together with the inverted seat in the carb fitting.......

The steel tubing works better because the flared end inside the nut is some what soft and pliable, allowing the inverted seal...so thatm,ight be your only way to go, for a while. Using 2 clamps is a good idea, I usually always use 2 clamps. if possible...
I may later try to use those copper bushings or steel lines. Maybe both, because I am JINXED anytime I try to connect any type of liquid-containing threaded pipes. They ALWAYS leak!!!!!
__________________
FRANKENTRUCK 1981 Chevrolet C10 Shortbed Stepside
GRANDTRUCK 1968 Chevrolet C10 Stepside Longbed
http://67-72chevytrucks.com/vboard/s...d.php?t=584617
PROJECT JIGSAW 1967 GMC C3500
GREAT WHITE 1986 Blazer M1009
HIGHWAY BY THE SEA is offline   Reply With Quote
Old 11-05-2018, 09:22 AM   #28
68Gold/white
Registered User
 
Join Date: Sep 2011
Location: Ark City, Kansas
Posts: 3,272
Re: Best fuel line thread sealant?

Quote:
Originally Posted by HIGHWAY BY THE SEA View Post
I may later try to use those copper bushings or steel lines. Maybe both, because I am JINXED anytime I try to connect any type of liquid-containing threaded pipes. They ALWAYS leak!!!!!
I have seen those copper bushings. The ones I am familiar with are for AN fittings. I have never seen them offered for inverted flare stuff ( I worked in a parts store, way back), but I have obviously NOT seen everything...

LOL, I think the race car person needs to come over and bend up a piece of steel line!!!
68Gold/white is offline   Reply With Quote
Old 11-05-2018, 10:31 AM   #29
HIGHWAY BY THE SEA
Registered User
 
HIGHWAY BY THE SEA's Avatar
 
Join Date: Nov 2012
Location: BY THE CAROLINA SEA
Posts: 917
Re: Best fuel line thread sealant?

Quote:
Originally Posted by 68Gold/white View Post
I have seen those copper bushings. The ones I am familiar with are for AN fittings. I have never seen them offered for inverted flare stuff ( I worked in a parts store, way back), but I have obviously NOT seen everything...

LOL, I think the race car person needs to come over and bend up a piece of steel line!!!
HA! Maybe, but I honestly do not know him all that well. I happened by his house when I was walking one day, and stopped to talk with him about his race car that he always works on in his yard. That was when I asked him for assistance in showing me how to set TDC and install a HEI in my GMC. He went beyond that by doing most of the work while my son and I assisted and listened carefully to his instructions. All three of us were under that hood! He was nice enough to do that for a neighbor that he does not really know. Great guy!
__________________
FRANKENTRUCK 1981 Chevrolet C10 Shortbed Stepside
GRANDTRUCK 1968 Chevrolet C10 Stepside Longbed
http://67-72chevytrucks.com/vboard/s...d.php?t=584617
PROJECT JIGSAW 1967 GMC C3500
GREAT WHITE 1986 Blazer M1009
HIGHWAY BY THE SEA is offline   Reply With Quote
Old 11-05-2018, 10:35 AM   #30
davepl
Registered User
 
davepl's Avatar
 
Join Date: Aug 2006
Location: Redmond, WA
Posts: 6,332
Re: Best fuel line thread sealant?

Quote:
Originally Posted by Willie Makeit View Post
Teflon tape is NOT a sealer. It's purpose is to lubricate the threads in order to torque to proper specs without galling and to achieve a mechanical seal with the threads.
"Thread seal tape (also known as PTFE tape or plumber's tape) is a polytetrafluoroethylene (PTFE) film tape commonly used in plumbing for sealing pipe threads."

You might be correct about how YOU use use, but it's still properly called PTFE Thread Seal Tape. I've been calling myself a plumber for over 40 years and selling sealants longer than that!

The tape is intended to seal in SPECIFIC applications, though in reality most applications people try to use it on here wind up being a flare or compression seal that the threads have no role in doing anything except clamping anyway.

So you're right that people here shouldn't call it thread seal the way they use it, but it still is called that, and particularly in LPNG, it's meant to seal in some cases.
__________________
1970 GMC Sierra Grande Custom Camper - Built, not Bought
1969 Pontiac 2+2 427/390 4-speed Coupe
1969 Pontiac 2+2 427/390 4-speed Convertible
davepl is offline   Reply With Quote
Old 11-05-2018, 10:54 AM   #31
Willie Makeit
Registered User
 
Willie Makeit's Avatar
 
Join Date: Oct 2013
Location: Alabama
Posts: 1,206
Re: Best fuel line thread sealant?

Quote:
Originally Posted by davepl View Post
"Thread seal tape (also known as PTFE tape or plumber's tape) is a polytetrafluoroethylene (PTFE) film tape commonly used in plumbing for sealing pipe threads."

You might be correct about how YOU use use, but it's still properly called PTFE Thread Seal Tape. I've been calling myself a plumber for over 40 years and selling sealants longer than that!

The tape is intended to seal in SPECIFIC applications, though in reality most applications people try to use it on here wind up being a flare or compression seal that the threads have no role in doing anything except clamping anyway.

So you're right that people here shouldn't call it thread seal the way they use it, but it still is called that, and particularly in LPNG, it's meant to seal in some cases.
regardless of what you call yourself, Teflon tape is NOT a sealant. I'm not a plumber & not gonna get into a pecker measuring contest with you, but I do work for NASA and know a lil' bit about sealing pneumatic and hydraulic systems, specifically on flight hardware.
Willie Makeit is offline   Reply With Quote
Old 11-05-2018, 11:22 AM   #32
davepl
Registered User
 
davepl's Avatar
 
Join Date: Aug 2006
Location: Redmond, WA
Posts: 6,332
Re: Best fuel line thread sealant?

Give me an RO number you order it under at NASA. What's it called, Willie? Sealant.
__________________
1970 GMC Sierra Grande Custom Camper - Built, not Bought
1969 Pontiac 2+2 427/390 4-speed Coupe
1969 Pontiac 2+2 427/390 4-speed Convertible
davepl is offline   Reply With Quote
Old 11-05-2018, 11:27 AM   #33
68Gold/white
Registered User
 
Join Date: Sep 2011
Location: Ark City, Kansas
Posts: 3,272
Re: Best fuel line thread sealant?

Quote:
Originally Posted by HIGHWAY BY THE SEA View Post
HA! Maybe, but I honestly do not know him all that well. I happened by his house when I was walking one day, and stopped to talk with him about his race car that he always works on in his yard. That was when I asked him for assistance in showing me how to set TDC and install a HEI in my GMC. He went beyond that by doing most of the work while my son and I assisted and listened carefully to his instructions. All three of us were under that hood! He was nice enough to do that for a neighbor that he does not really know. Great guy!
Almost all parts stores sell steel tubing that is flared on both ends with the flare nuts already installed, in different lengths. I would like to think that the carburetor end is the same fitting.

You can take a close measurement and get a piece that is slightly long thatn what you need. You can generally make the bends work to make connections on both ends. Not particularly easy, might buy 2 pieces (I usually do, and I have done this too many times, experience wise...). Mr race car might be able to gitterdone easily! Then I would place the inline fuel filter in the hose feeding the pump...

Did you ever find center caps for your aluminum wheels??? Those look to be Western (Brand name) turbine wheels. Might have to measure the hole size and go from there. Not sure if Western still makes aftermarket wheels. An internet search might do the job...I prefer rally wheels...although those turbine wheels would look better with some TLC, and polishing the smooth surfaces. THere are folks that restore wheels, your's wouldn't need much, but some of those companies don't know when to stop charging for their services...
68Gold/white is offline   Reply With Quote
Old 11-05-2018, 11:30 AM   #34
Willie Makeit
Registered User
 
Willie Makeit's Avatar
 
Join Date: Oct 2013
Location: Alabama
Posts: 1,206
Re: Best fuel line thread sealant?

Quote:
Originally Posted by davepl View Post
Give me an RO number you order it under at NASA. What's it called, Willie? Sealant.
NASA doesn't use RO numbers, sorry. But I can tell you that I just did a quick search and out of about 60-65 line item descriptions for TEFLON TAPE or PTFE, the word SEAL or SEALANT was not in any of them.
Willie Makeit is offline   Reply With Quote
Old 11-05-2018, 12:16 PM   #35
davepl
Registered User
 
davepl's Avatar
 
Join Date: Aug 2006
Location: Redmond, WA
Posts: 6,332
Re: Best fuel line thread sealant?

If you won't be specific I can't help you. There is a ptfe film tape used as a thread lubricant, but it's different from the thread sealing tape pictured here.

As for the stuff in this thread, https://en.wikipedia.org/wiki/Thread_seal_tape
__________________
1970 GMC Sierra Grande Custom Camper - Built, not Bought
1969 Pontiac 2+2 427/390 4-speed Coupe
1969 Pontiac 2+2 427/390 4-speed Convertible
davepl is offline   Reply With Quote
Old 11-05-2018, 12:43 PM   #36
Willie Makeit
Registered User
 
Willie Makeit's Avatar
 
Join Date: Oct 2013
Location: Alabama
Posts: 1,206
Re: Best fuel line thread sealant?

Quote:
Originally Posted by davepl View Post
If you won't be specific I can't help you. There is a ptfe film tape used as a thread lubricant, but it's different from the thread sealing tape pictured here.

As for the stuff in this thread, https://en.wikipedia.org/wiki/Thread_seal_tape
I don't recall asking for any help. PTFE tape, regardless of name its sold under, is NOT a proper sealant for mechanically sealing threads.
Willie Makeit is offline   Reply With Quote
Old 11-05-2018, 12:56 PM   #37
special-K
Special Order

 
special-K's Avatar
 
Join Date: Nov 2004
Location: Mt Airy, MD
Posts: 85,862
Re: Best fuel line thread sealant?

Quote:
Originally Posted by Willie Makeit View Post
Teflon tape is NOT a sealer. It's purpose is to lubricate the threads in order to torque to proper specs without galling and to acheive a mechanical SEAL with the threads.
Alright, I sure don't want to hop in this or see it continue on. But in the quote above it sure looks like a contradiction. Ok, so it's a component used in creating a seal. Is the tape a seal? No. Are the treads a seal? No. But Teflon tape used on threads creates a seal. The fact is it doesn't hurt to use it in this case, even if it's belts & suspenders. What is really needed is a correct fuel line.
__________________
"BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed"

GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project)
GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling)
Tim

"Don't call me a redneck. I'm a rough cut country gentleman"

R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~
special-K is offline   Reply With Quote
Old 11-05-2018, 01:04 PM   #38
davepl
Registered User
 
davepl's Avatar
 
Join Date: Aug 2006
Location: Redmond, WA
Posts: 6,332
Re: Best fuel line thread sealant?

Quote:
Originally Posted by Willie Makeit View Post
I don't recall asking for any help. PTFE tape, regardless of name its sold under, is NOT a proper sealant for mechanically sealing threads.
Wait, which kind isn't for thread sealing? The thread sealing kind or the film kind? Because there are two different types. See I was going to be all pedantic and helpful and give you an out whereby you're probably thinking of ptfe friction reduction film tape, but you doubled down, so... oh wait, I already did. But you're still a solid red X in the wrong column today.

I'll just leave this exerpt from 3M Part Number 48, their teflon thread sealant tape, which explains how it should be used. Reader can decide if what you're saying jives with the manufacturer:

"Scotch® Thread Sealant and Lubricant 48 is a white unfused plastic film made of polytetrafluoroethylene (PTFE). This fluorocarbon resin film tape designed to provide a leak-resistance seal when used as a pipe thread sealant."

I can guess the next steps, so I'll leave them to the reader as an exercise and take my leave... I don't personally use any of the stuff in fuel applications, for what its worth. Maybe on bushings and other tapered-thread stuff. Can't think of anywhere its under pressure through, in stock form I think it's all taper or clamp.
__________________
1970 GMC Sierra Grande Custom Camper - Built, not Bought
1969 Pontiac 2+2 427/390 4-speed Coupe
1969 Pontiac 2+2 427/390 4-speed Convertible

Last edited by davepl; 11-05-2018 at 01:09 PM.
davepl is offline   Reply With Quote
Old 11-05-2018, 01:47 PM   #39
Willie Makeit
Registered User
 
Willie Makeit's Avatar
 
Join Date: Oct 2013
Location: Alabama
Posts: 1,206
Re: Best fuel line thread sealant?

ok bud. you win, you got the last word.
Willie Makeit is offline   Reply With Quote
Old 11-05-2018, 02:38 PM   #40
HIGHWAY BY THE SEA
Registered User
 
HIGHWAY BY THE SEA's Avatar
 
Join Date: Nov 2012
Location: BY THE CAROLINA SEA
Posts: 917
Re: Best fuel line thread sealant?

Quote:
Originally Posted by 68Gold/white View Post
Did you ever find center caps for your aluminum wheels??? Those look to be Western (Brand name) turbine wheels. Might have to measure the hole size and go from there. Not sure if Western still makes aftermarket wheels. An internet search might do the job...I prefer rally wheels...although those turbine wheels would look better with some TLC, and polishing the smooth surfaces. THere are folks that restore wheels, your's wouldn't need much, but some of those companies don't know when to stop charging for their services...
Not yet! I sure would like to though! The powder coating is perfect, but the lack of center cap is very noticible.
I just sold my Rally wheels to a board member!
__________________
FRANKENTRUCK 1981 Chevrolet C10 Shortbed Stepside
GRANDTRUCK 1968 Chevrolet C10 Stepside Longbed
http://67-72chevytrucks.com/vboard/s...d.php?t=584617
PROJECT JIGSAW 1967 GMC C3500
GREAT WHITE 1986 Blazer M1009
HIGHWAY BY THE SEA is offline   Reply With Quote
Old 11-06-2018, 04:39 PM   #41
GRX
Registered User
 
GRX's Avatar
 
Join Date: Jul 2010
Location: MD
Posts: 1,937
Re: Best fuel line thread sealant?

Teflon tape does serve to lubricate threads. But not made for sealing? That is a new one. It is designed and used for that very purpose millions of times every day. Grades depending on application. Red for larger joints. Yellow for fuels, Green for sealing oxygen systems, and so on.
__________________
1969 c-10 Step Side Long Bed. I-6 250cid = = 1969 Pontiac GTO hard top. 400, 4-speed.
GRX is offline   Reply With Quote
Old 11-07-2018, 12:24 PM   #42
davepl
Registered User
 
davepl's Avatar
 
Join Date: Aug 2006
Location: Redmond, WA
Posts: 6,332
Re: Best fuel line thread sealant?

There are several types, as you note. It's quite possible that Willie is using a style intended only to prevent galling, and that has nothing to do with sealing. That's why I asked for the RO or part number early on to look it up instead of guessing.

I think the best answer is "it does both" but there are only certain applications where it's is appropriate as a sealant.

95% of the people using it on the threads have no idea that the seal is from a 45 or 37 degree tapered flange and not the threads anyway! Other than where your pipe nipple screws into the intake manifold for your heater hose... not many places.
__________________
1970 GMC Sierra Grande Custom Camper - Built, not Bought
1969 Pontiac 2+2 427/390 4-speed Coupe
1969 Pontiac 2+2 427/390 4-speed Convertible
davepl is offline   Reply With Quote
Old 11-07-2018, 12:30 PM   #43
geezer#99
Registered User
 
geezer#99's Avatar
 
Join Date: Aug 2009
Location: Bowser
Posts: 13,510
Re: Best fuel line thread sealant?

Good info Dave!
Far too many people believe that if it has threads it needs sealer.
And the same people use a whole tube of silicone sealant where a thin bead is all you need.
geezer#99 is offline   Reply With Quote
Old 11-07-2018, 12:34 PM   #44
68Gold/white
Registered User
 
Join Date: Sep 2011
Location: Ark City, Kansas
Posts: 3,272
Re: Best fuel line thread sealant?

Quote:
Originally Posted by HIGHWAY BY THE SEA View Post
Not yet! I sure would like to though! The powder coating is perfect, but the lack of center cap is very noticible.
I just sold my Rally wheels to a board member!
Hey, Google, Western wheels center caps, you may find an answer to your center cap situation....
68Gold/white is offline   Reply With Quote
Old 11-07-2018, 04:18 PM   #45
jaros44sr
Registered User
 
jaros44sr's Avatar
 
Join Date: May 2006
Location: Philadelphia, Pa. 19454
Posts: 9,421
Re: Best fuel line thread sealant?

OK, shouldn't need to use any sealant, as it is a single fare. I mean how long has these trucks been on the road with out a fuel leak, you would think there would be a recall by now.

Pulled a old carb off the shelf, to take the fitting apart, first wrench (pipe) started to round out the nut, so I grabbed one of my new wrenches, and it grabbed the shoulder much better, had to tap it with a wooden handle. That sucker was on there!!!!

[url=https://flic.kr/p/QALDQS]20181107_145137

After both the adapter and fuel line were off, there is no obvious reason why this fitting should leak, unless the flair is cracked. The PO did use teflon tape, as there is still remnants of it on the fuel line

[url=https://flic.kr/p/29XW22d]20181107_145056

JMHO, but there should be no reason to use any sort of teflon with fuel as I believe the fuel breaks it down.....use it on your kitchen faucet
__________________
Semper Fi...Uncle Sam, you da man

All parts offered to help are free, unless otherwise noted

Dont try this stuff in my build thread, unless you have 55 years of mechanical OTJ training
SAFETY FIRST

AS usual, off topic

They say your mind goes second, can't remember the first


Jim

Last edited by jaros44sr; 11-07-2018 at 04:28 PM.
jaros44sr is offline   Reply With Quote
Old 02-04-2019, 04:06 AM   #46
Mike_The_Grad
Senior Member
 
Mike_The_Grad's Avatar
 
Join Date: Oct 2013
Location: Santa Paula, CA
Posts: 582
Re: Best fuel line thread sealant?

In case this is still up for discussion. Try "lapping" the inverted flare portion of that brass fitting or any flare type of joint. How I usually go about it when I am either bending a premade length of steel tubing with tube nuts already installed, or creating a new inverted flare on a piece of steel tubing is: first use a tubing cutter. Take a rat tail file or round chainsaw file and ream the i.d. of the tubing. Then take a fine cut flat file and put a slight chamfer or bevel on the o.d of the tubing.(really only necessary for double flaring of lines.) Then put a thin smearing of high pressure wheel bearing grease on the conical flaring die.(also in tube bending channel if making a bend, it allows smooth operation of the bender and flaring die.) Onve the flare is made wipe with a rag, grab a piece of 1500 or 2000 grit paper and use your finger tip to work the flare smooth,wipe again and your done. On double flares I put a little water on the sand paper to help cut the seam joint down a little faster. But same result. Oh, and now I ALWAYS put those store bought premade pieces into my flaring block and "seat" the flaring die to ensure the flare is concentric. Meaning just enough pressure to ensure it's even. Or another suggestion if it's possible, is to make the flare nut joint up by hand then rotate the tubing into the joint, once you cant turn it anymore back it and the nut off a 1/4 turn then the tube a 1/4 turn beyond that and retighten by hand. I do this a couple of times at different spots on the tube. In my opinion, ever since I began doing these simple quick things, i have yet to have a leak. It's also important to use 2 wrenches when tightening a flare joint and as long as the wrenches are the correct size, dont be afraid to put some torque into it. If you start rounding the nut off, then you dont have the right wrench or the tube nut is cheap.
__________________
1972 C/10 LWB - Mine
1964 C/10 LWB - My Dad's

Instagram: Mike_The_Grad
Mike_The_Grad is offline   Reply With Quote
Old 02-04-2019, 10:57 AM   #47
Sheepdip
Senior Member
 
Sheepdip's Avatar
 
Join Date: Nov 2018
Location: Waterford California
Posts: 2,365
Re: Best fuel line thread sealant?

Quote:
Originally Posted by Willie Makeit View Post
Teflon tape is NOT a sealer. It's purpose is to lubricate the threads in order to torque to proper specs without galling and to achieve a mechanical seal with the threads.
^^^^^^^^^^^This is 100% correct^^^^^^^^^^^^^^^^
Sheepdip is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 04:47 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com