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MG MGB Technical - Teflon Tape or Not?

I'm in the process of installing a valve, brake lines and a master cyl in my 74 CB roadster. I've heard both ways, but want to see what MG people have to say.
Should I use Teflon tape or anything else when connecting my brake lines?


Cleve Crews

No, no need at all. As long as you get the unions lined up orrectly they will seal perfectly. If there are leaks it will be an underlying problem, not the joint.
P M Gregory

No Teflon tape at all with brake work. The double flares and joints must be capable of sealing perfectly without any kind if sealer. Denis
Denis4

PTFE tape is a thread sealer. Brake connections don't rely at all on the threads sealing. The threads are only there to exert pressure on the conical joints, or cu washers.
Allan Reeling

As above, about where the seal is, BUT teflon tape on the threads, only, will provide lubrication and anti seize to the threads.

Herb
Herb Adler

a good quality PTFE tape might prove to be too thick so buy the cheap thin stuff from places like B&Q
Nigel Atkins

The problems I for see with tape on brake joints is over tightening as it removes the "feel" and with any kind of a safety inspection any visible sign of sealer would trigger a doubt as to the joints integrity.
Denis
Denis4

I have never heard of this, the idea worries me...

Surely the little bits of teflon tape that get torn off are going to wreak havoc with the seals in the brakes? Or work their way up into the master cylinder and block the pipes? Or jam the pistons in the calipers in the on position?

Am I the only one glad I'm driving around in Alabama ;-)

Sorry, Cleve but no PTFE!

Mike
Mike Standring

Mike Stranding is absolutely correct, teflon tape should never be used of any brake fitting. His statement of little bits of teflon tape wreaking havoc with the seals in the brakes is compounded by the fact that when in something like brake fluid, the tape becomes nearly transparent and is exceedingly difficult to locate and remove. Cheers - Dave
D W DuBois

All,
Thanks for the input. I'm not a mechanic, just an amateur fiddler.
I was thinking about putting the tape on the threads, not where the seal is on the pipe, or where the nut fits on the seal tip.
As you can see in the picture (sorry for the focus)there are three numbered locations.
1. The pipe tip (flare)
2. The compression area where the nut fits the pipe tip flare.
3. The threads

After the input from all you, I've decided not to put tape on the threads. I don't want to have a catastrophic failure of my brakes, although I'm not sure how the tape would get past the compression area (2)and the pipe joint (1), then migrate to my master cyl.



"Am I the only one glad I'm driving around in Alabama" ;-)
Mike

I'm glad you like driving around here Mike. I moved to the South from Tustin, California and it is so much pleasant here with the exception of the humid weather.


Cleve Crews

Good plan. As Allen said, the threads don't seal anything.

Teflon tape and silicone are two things that cause more problems than they solve in the hands of amateur mechanics (I've seen blown engines from the latter).

Assemble your brake pipes and tighten and make sure everything is clean and dry, and then bleed them. Then get someone to put moderate pressure on the pedal and crawl around inspecting to be sure they are fluid tight. I've seen over tightened flare ends get grooved and weep.
Bill Spohn

Just watched a show on TV called Garage Squad, episode "Ford on Fords" and noticed they were putting Teflon tape on all brake fittings. They even made the point to say not to let the tape cover the openings and block the flow of fluid.
I knew I had seen this done before.
After reading the input by all of you, I won't be using it on my cars.
Cleve Crews

Cleve, did MG ever use PTFE on any brake fitting, the answer is NO, as other people have said don't use it. I wouldn't take too much notice of any television program.
I worked for 25 years testing prototype brake pads and lining for a british brake manufacturer, whe did lots of modifications to new vehicles and we never used PTFE on hydraulic brake pipe fittings.
regards John
john wright

This thread was discussed between 23/10/2014 and 11/01/2015

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