brazing a hydraulic line

coloradotrout · Oct 31, 2005

I have a small leak in the metal pressure hydraulic line right at the fitting. It leaks a couple of drops per minute. I was thinking maybe I could braze it shut. I cannot even see where it's leaking. At home depot they have 3 or 4 kinds of braze - bronze, nickel-silver, and a couple of others (aluminum maybe). A replacement part is $250.

RedRocker · Oct 31, 2005

Silver solder should do the trick. Brass would probably be fine too.

coloradotrout · Oct 31, 2005

Just regular old silver solder? the stuff used for copper pipes?

Just heat the joint up.. and apply the solder?

I suppose it best to sand off as much paint/corrosion as I can..

HomeBrew2 · Oct 31, 2005

I'm pretty sure Redrocker meant real silver solder. Typically you need less heat than brass which is nice for small/thin stuff. A welding supply should have it. If not a place that sells jewelry making supplies. It comes in several melting point temps. And it uses it's own kind of flux.

3RRL · Oct 31, 2005

I agree with RedRocker, silver solder will work just fine.
Be sure to prepare the area by removing as much paint and crud as you can around the area. Then apply the flux neatly and evenly. The flux application is key to a good job because it controls the flow of the solder. I use Harris "stay-silv" silver solder flux.

geneP · Oct 31, 2005

If you can't see where it is leaking, how are you going to solder it? Are you going to solder the nut/connector to the steel line? Maybe it is leaking at the seat, or o-ring if it has one, and removing the connection might reveal the source of the leak.

RoyJackson · Oct 31, 2005

"Just regular old silver solder? the stuff used for copper pipes?"

That's not silver solder...that's a lead/tin alloy used to sweat copper joints.

Real silver solder will require more heat...probably MAPP gas (at least).

You can give it a try, but I'm not sure any solder will work on a hydraulic system that pushes >2000 PSI. Of course, some aerospace hydraulic fitting are silver soldered...I know...I did some whilst in the Navy. But these joints were not pinhold leaks.
Can't hurt to give a try though!

VA_Joe · Oct 31, 2005

I agree - that is a lot of pressure for a soldered connection.

JerryG · Oct 31, 2005

I don't know what you have in your area, but you could take the old line to a hydraulic shop. We have one in the area that makes up metal lines as well as hoses. It would be a LOT less expensive than the dealer.

HomeBrew2 · Oct 31, 2005

You might want to read up on silver soldering, aka silver brazing ... it's pretty strong ... nothing like soft-solder. Also, around these parts, lead in solder, for potable water, has been outlawed for a long time ... kindof a safety issue. One compound for potable water pipe soldering uses tin, copper and selenium.
Cheers!