Brake line fittings and flaring, SAE and NPT

[64Chevelle]

I'm quite new to brake lines and flaring. I'm familiar with the 45 degree SAE double flare system used in my current components. I have just bought a line-lock from summit with 1/8 NPT. The brake line fittings in the line lock is flat in the bottom compared to the rest of the brake system which has the 45 degree SAE fitting. Also, I've converted to 2002 ls1 (Camaro) rear brakes with a 10 mm Metric fitting.

I'm using 3/16" tubing.

How do I go about flaring the 1/8 NPT to make it seal? I'm going to have to use SAE nuts w/45 deg. flare in one end (to the Master Cylinder) and a different 1/8 NPT nut in the other end to mate with the line lock, or is there some kind of adapter?

In the rear I have to cut off the existing tube ends, put on a M10 nut and re-flare it. Any thing else to watch out for?

[64Chevelle]

Ok, think I figures it out... The NPT fitting is unflared which means it is sealed by using teflon tape or a sealing compound (which might contaminate the system). Sounds like a bad idea to me...

The LS1 brakes lines are bubble flared with a metric 10 mm nut, the bubble flare is essentially the first step of the double flare process.

I might flare all the tubes with the standard inverted 45 degree double flare and just use adapters for the special type fittings... We'll see what I end up doing :)

I found out about bubble vs inverted double flare from this link:
http://www.pharmacy.arizona.edu/staff/wunz/NoABSTCS/DoubleFlare.html

[1969CamaroRS]

I just put in a Hurst system in mine, I had to get 3 adapters and some extra nuts. I had to cut off some of the existing nuts as they were too big to fit and use a smaller nut. There is a compression fitting female to male NPT adapter that I got at the local hardware store. I brought the line lock with me and one the lines / nuts and we looked around till found what would work.

I wouldn't use teflon tape I bought a tube of high temp brake line sealer from Permatex, its like a paste and it compatible with brake fluid. Teflon tape will just get eaten up by the brake fluid and possibly contaminate it.

Hope this helps.

[Apogee]

Most of the Wilwood and Summit line-locks and adjustable proportioning valves come with 1/8 NPT to 3/8-24 SAE inverted flare adapter fittings...if not, they're readily available.

As for the rear brakes, the LS1 F-body caliper requires a M10x1.0 banjo bolt and the factory hose is a M10x1.0 ISO bubble flare. You can either run those hoses and the appropriate matching tube nuts or run different hoses and go SAE. The fewer the adapter fittings in the system the better IMHO.

Tobin
KORE3

[JRouche]

Dont ever use teflon tape for fluid fittings. NPT fittings are tapered threads, self sealing. JR

http://www.wilwood.com/PDF/ds488.pdf

[1969CamaroRS]

Actually anything that seals on the threads does need some type of sealant or it will weep over time.

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

This means that NPT fittings must be made leak free with the aid of thread seal tape or a thread sealant compound

[MonzaRacer]

Personally I use anaerobic sealer, sucks to try to pull it apart but a little pncil torch adding smal amount of heat and tada it will come out, as for me I used standard liquid teflone tape or leaving one to two threads on bottom free of tape the yellow thick tape for gas lines (natural/LP) and only like 1 1/2 wraps.
I now have my hydraulic flaring tools so I WILL NOT HAVE CROSS BREEDING ISSUES again and I can use/upgrade all my vehicles to later model filters!

[64Chevelle]

Most of the Wilwood and Summit line-locks and adjustable proportioning valves come with 1/8 NPT to 3/8-24 SAE inverted flare adapter fittings...if not, they're readily available.

As for the rear brakes, the LS1 F-body caliper requires a M10x1.0 banjo bolt and the factory hose is a M10x1.0 ISO bubble flare. You can either run those hoses and the appropriate matching tube nuts or run different hoses and go SAE. The fewer the adapter fittings in the system the better IMHO.

Tobin
KORE3

I agree, I want to keep the number of adapters to a minimum, but I do consider using NPT to SAE inv. flare adapter fittings for the line lock. For the rear I'll be using the factory LS1 hose to the caliper and reflare the axle hard lines with the M10x1.0 ISO bubble flare.

Thanks for the advice!

[64Chevelle]

I just put in a Hurst system in mine, I had to get 3 adapters and some extra nuts. I had to cut off some of the existing nuts as they were too big to fit and use a smaller nut. There is a compression fitting female to male NPT adapter that I got at the local hardware store. I brought the line lock with me and one the lines / nuts and we looked around till found what would work.

I wouldn't use teflon tape I bought a tube of high temp brake line sealer from Permatex, its like a paste and it compatible with brake fluid. Teflon tape will just get eaten up by the brake fluid and possibly contaminate it.

Hope this helps.

That helps a lot. The install instructions for the line lock recommended using teflon tape and be careful with a liquid thread sealer since (I quote) "it can an will contaminate the system". But the abovementioned sealer should be perfect for this.

[JRouche]

Actually anything that seals on the threads does need some type of sealant or it will weep over time.

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

Yes, you are right, I kinda cut myself short when I said NPTs were self sealing. They are, compared to straight, non tapered threads. I was caught up with the tape issue. And I still say tape as a thread sealing method doesnt have any place in fluid or gas piping. Not when there are soooo many products out there that do work. Teflon tape is a misused product and its passed its usefulness with so many other products available. I dont see ANY use for it for thread sealing really. So Im not buying the teflon tape route. Once you have used a good thread sealant out of a tube or can then the difference is apparent. You will never use the tape again..JR

[MonzaRacer]

JROUCHE, I disagree as I have some actual places that ONLY tape worked, oh and in certain gas applications you can ONLY use the thicker yellow thread tape by regulation.
Also if you do know what your doing thread tape will not cause any issues, if you are Mr. Sloppy with it then yes you will have issues.
And as for anyone listing wikipedia for actual technical documentation, let me go post up a few things then I can link to them. Sorry but a lawyer tried to use wiki for a legal point, and it cost a friend some serious bucks.

[1969CamaroRS]

Teflon tape is a misused product and its passed its usefulness with so many other products available. I dont see ANY use for it for thread sealing really. So Im not buying the teflon tape route. Once you have used a good thread sealant out of a tube or can then the difference is apparent. You will never use the tape again..JR

Completely agree, teflon tape is bad juju. There are a lot better choices that don't end up contaminating the lines you are trying to seal.

[Skip Fix]

Something to watch on your Summit Line Locks regarding those pipe threads. I've got two I'm sending back. Both were tapped too much so the fittings hex hits before the threads interference fit seals. One I also couldn't get the bolt/nut on the bottom to seal with new O rings even. They would weep from those locations after pressure not just sitting there.

New Hurst one is alot better quality metal body and threads aren't too big, and smoother. No leaks after jacking with teh Summit one for a week, new fittings, re bleed etc etc.