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Discussion Starter #1
I got everything all hooked up today and bench bled the master cylinder for my dual MC conversion...get the SWMBO out there to push the brake pedal for me so I can bleed the system. Everything seems to be going good, I see bubbles in the container the bleeder hose is running into so I know air is pumping through the tube.

BUT here's the problem, when I went back up to the front of the car to check the fluid level in the MC, I noticed leaks from about half of the adapter fittings I was using. They are tightened down tight enough (I think) and they are the correct reverse flare fittings. One thing I noticed where there were NOT leaks was at the proportioning valve, which came shipped with a sort of rubbery sealer on the threads. Should I have put some sort of sealer on all the threads? They weren't on any when I took the old lines off the car...but maybe new lines need it?

Geez how frustrating I get it all ready to go, excited to drive the thing today and now this. Somebody, anybody know the answer to this? Thanks guys!
 

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You need to dissasemble the fittings @ the mc and get some hydraulic thread sealer. it will
take care of all the leaks. good luck
 

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Did you buy your lines with fittings or did you make your own? You need a double flairing tool and you need to read the directions on how to flair. Step one, you put the adapter in the line and compress it. You will need to work on the distance left out, because that makes the difference on the bend. Then remove the adapter and compress the flair all the way in. If it is not smooth and symetrical, it will leak. The tape isn't the way to fix leaks on a brake system. the mating of two surfaces makes the seal. Reason being you have a built up amount of pressure. Pressurized lines have to be treated with respect. Goop and tape are not the fix. Look at your end lentgths. Make sure you have the distance to turn in for a good seal. The fitting sizes differ between certain lines. Also, there are two style of lines. Make sure you have the matching types. My experience is that these are color coded. Good luck, it shouldn't be to hard to figure out.
 

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Are they leaking from the threads or from the inside of the fitting? If it is through the tube/fitting and not the threads then sealant will do no good.
 

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Discussion Starter #6
I believe most of them were leaking through the threads. If all else fails I have some photos I can post tonight if the leaks continue. I have put some sealer on the threads and we'll see if that helps. I will check the mating surfaces, but the lines were from classic tube, so they were pre-bent and pre flared. The flares looked perfect to me, and seemed to fit symmetrically into the fittings. I will check this all over again though. Hopefully it was just leaking through the threads.
 

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You are not supposed to use any kind of goop on the threads for double flare tubing. That is what the double flare is all about. You have to be sure the end of the tubes are square into the fitting, when you thread the nuts into the fittings.They cannot be cocked at all. Do not use tape or goop!
 

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I'm going through a similar process with a new set of stainless lines. One manufacturer of the lines notes that stainless lines can be herder to seal, and recommends Permatex 14A w/ teflon on the threads and shoulder as follows:

Q. Will my new Stainless Steel lines leak? I've heard they are harder to seal.

A. Stainless Steel lines ARE harder to seal, particularly when they are being installed in a used component. Stainless material is harder than the original material, and lacks the soft lead/tin coating. The seat in a used valve, or other used part usually has an impression left by the original flare. The harder Stainless material does not conform as easily to the old impression. By following a few simple extra steps this problem can be virtually eliminated. We recommend the use of "Permatex #14a Thread Sealant with Teflon". This product comes in a small tube, and is available at most hardware stores. A dab placed on the tube under the fitting, plus a dab on the threads will usually eliminate any sealing problems.

This was from the Fine Lines web page (www.finelinesinc.com).

Carl
 
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