Tiny Brake Leak

[eamici]

Hello,
I’ve had an issue with a tiny brake leak (one or two drops per week) that has prevented me from proceeding with my build.

The leak seems to be coming from the rear driver side splitter/coupler. I can’t be sure of the source however because the fluid is evaporating faster than I can detect it. The only way I know that there’s a problem is that there is some slight pooling of liquid at the rear most end of the main 4” round frame….. which is nowhere near the coupler.

Can I uninstall/reinstall this piece using lock tight or some other sealant? I’ve completely replaced the rear lines, but the problem has not been resolved.


150766

[Railroad]

First time or new flares seat better or easier, if you tighten them, loosen and re tighten. You do not need to remove the blocks or tees. Normally you will not lose fluid, but if you do re bleed the end of the car you are working on. Any fluid that gets on the flare mating surfaces will act like a lube and help seating.
You will get it, easy, peasy.

[Avalanche325]

Do not use sealant on flare fittings. It is not the threads that do the sealing, it is the flare and cone smashing together. You do have to REALLY tighten them. That is why there are specific flare nut wrenches, because a regular wrench will often spread and round off your fitting before you get enough torque on it. But then again, over-tightening can cause a crack.

Check your flare for cracks or even a tiny bit of debris with a magnifying glass. Also check the fitting. The tiniest barb can stop it from sealing. Even a scratch can do it. You can dress it with fine sandpaper if needed. Super clean it if you do.

[JohnK]

Check your flare for cracks or even a tiny bit of debris with a magnifying glass. Also check the fitting. The tiniest barb can stop it from sealing. Even a scratch can do it. You can dress it with fine sandpaper if needed. Super clean it if you do.

This ^. I bent and flared my own brake lines. I inspected every flare I made with one of these (https://www.amazon.com/gp/product/B078N34WZR/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1). I found a couple that had tiny cracks in them that I wouldn't have seen with the naked eye, and I have no doubt those would have leaked.

[egchewy79]

also brake fluid doesn't evaporate. look for a trail somewhere. you can also wrap sections of your line with paper towel and see which sections get wet with brake fluid. this can help narrow down the location of the leak.

[Rdone585]

Pressure in the brake system is sometimes needed to find small leaks. Have someone press on the pedal while you look for the leak. If you can't find a helper the proper length piece of 2x4 can sometime do the trick. Oh, wait a minute, those are worth their weight in gold right now. Maybe just wait for a friend to lend a foot.

[CraigS]

After your inspection (personally if you take it apart I would replace the union or Tee just because they don't cost much), if you are using a tubing wrench, just keep tightening it. I sometimes scare myself as to how hard I need to tighten to stop a seep but I haven't found another solution other than switching to NiCopp line which is softer than steel so seals more easily.

[rich grsc]

I found when assembling the fittings, a small drop of brake fluid on the threads and back side of the flare helps to act as a lubricant. That and they really need to be tight. Most tubing wrenches are short, so I don't worry about stripping the fittings>short wrench, low leverage.
I agree if the leak is at the Tee, the reverse flare may be damaged, cheep to replace

[CraigS]

I found when assembling the fittings, a small drop of brake fluid on the threads and back side of the flare helps to act as a lubricant....
Thanks for adding that Rich. BTW, a general rule for assembling anything that carries liquid is to use a bit of whatever fluid that system will carry as a lube.

[jwd]

I had the same issue on my clutch side. I flailed all my own brake lines using SUR&R flailing tool(same one Eastwood sells.) and had no leaks. Bought 2 per made lines and both would not seal. Buddy of mine turned me on to these. Had them at my local hydraulics store.no more leaks. They told me a lot of remade stuff is crap. My company sells the flailing tool mentioned if someone needs one I will sell at cost.PM me.

[jwd]

That should be flair tool and pre-made

[Wayne r mckee]

I had a few small leaks , I bought the lapping tool from koul tools , stopped the leaks first try .