teflon tape on brake fittings?

[steven m]

Do any of you use teflon tape on your brake fittings?  I'm getting some weeping at the caliper (Brembo) and do not want to over-tighten.  Would anti-seize do the same thing?

Thanks

Steve

[montmil]

Teflon tape on brake line fittings has always been a big no-no in the industry. Small bits can be easily cut during the refitting of components; these bits enter the brake line and can cause stoppage. I would advise against using the tape. Anti-seize is not a sealant. There is a soft pipe sealant that may be useful if the initial 2-3 threads are not coated prior to assembly.

Monte

[Bob_Roller]

The threads are not pipe threads (tapered threads) to the best of my knowledge .

The end of the metal line, seals against the seat in the caliper .

If fluid is getting by this, you need to look at the two parts, and see if there is any damage, corrosion pitting or something similar .

[steven m]

I suspected what Monte has confirmed re potential contamination and blockage.  Am I understanding correctly that the issue can be the hard pipe fitting isn't seated completely?  So I would need to loosen it, make certain it is seated and then retighten?  As I wrote previously, have no desire to strip expensive Italian caliper threads!

Steve

[Bob_Roller]

You may just want to try loosening the nut a bit, so you can move the line around a bit, then re- tighten the nut, and see what develops .

[Ed Miller]

Yeah, what Bob (as usual) said.  Try twisting it to get it to seat better.  Sometimes they get dinged up.  I bet there is a tool to smooth the seat in the caliper, if that's where the damage is but I"ve never seen one.

[Barry]

The metal brake pipe into the caliper is a swaged end metal to metal seal which if clean and undamaged should seal ok. It works because there is a relatively small surface area which results in a high pressure at the metal to metal contact surfaces. The end of the bleed nipple is the same convex shape and seals in the same way.

I agree with Monte point about PTFE tape being inappropriate if used at the point of  hydraulic seal however I have used it on the top half of the bleed nipple to help prevent air getting passed the threads when bleeding the brakes.  This is well away from the brake fluid once the bleed nipple is closed and unlikely to cause contamination. PTFE is not incompatible with brake fluid in terms of material properties you just don't want small bits of it in there.

[steven m]

Right.  I'm going to loosen the brake pipe and rotate it back and forth a couple of times to establish a good seal, apply GENTLE pressure on it, and then tighten up the nut.  The sealing surface appears clean and smooth on the brake pipe.  It is now obvious, duh, that tape or sealant would just be a hillbilly solution, masking the issue.  Of course, perhaps the weeping, which appears as a very small wet spot at the pipe/caliper junction, is simply residual fluid from installation working itself out of the threads due to heat.  No puddles of fluid or spongy brake feel which would indicate it is sucking in air.

Thanks for the info guys.  I'll keep you posted.

Steve

[Rob Valdez 79 R65]

I have a spare left-hand pipe (NOS), if you need it.

[steven m]

Thanks, Rob.  I may take you up on it.  

Steve