Can you braze a hydraulic line?

[mrmikey]

Compression can’t handle hydraulic pressure.

Nope, compression.
Swagelock, Parker are a couple of companies that make compression fittings, no flaring tools needed, which if you've only got one joint to do is an advantage. Not to mention if you're in cramped quarters you don't have to wrangle a flaring tool into place.
I've used Swagelok in #8, 12 and16 sizes and they work great, not cheap by any means tho......Mike

 

[not2old]

Don't have any experience with something like this but nobody has mentioned fire risk.

 

[orezok]

Could it be cut out and replaced with a hose?

 

[rScotty]

Where exactly does that line run? What does it do? Where did it split?
Are you really considering doing it in place?

Yes, on clean metal you can certainly silver braze hydraulic tubing. That's how it's done in industry - and I think a good craftsman can do as well. But as you know, anytime it's not completely clean the joint is a gamble.

This is the tip I use for micro-welding with a big old funky Craftsman "bridge-building" torch. Old Craftsman torches had nice valves....

I don't do much brazing or silver, but it works well for that too.
This tip is basically just what you think it is... a piece of copper tubing soldered into a hole counter-drilled into a normal size welding tip and then the tiny flame orfice for the copper is made by annealing the end and hammering around the shank of a tiny number drill.
The resulting flame is about the size of a grain of wheat. I run it with 3 or 4 psi acet & 5 oxy.

 

[59 Sons]

I am a refrigeration tech so I will be applying my practices and tools to this. I will be using an air acetylene turbo torch with a rosebud about the size of your thumb nail. I usually have no problem doing up to inch and an eighth copper with an MC tank. Most of my experience with steel is brazing copper lines into steel king valves on compressors. We use a paste flux on the mating surfaces and then a 45 to 55% silver alloy brazing rod. Or a hollow core brazing rod with flux inside. I will blast the oil out of the tube with nitrogen and then set my regulator to bleed a low pressure feed of nitrogen through the tube while I heat it up. Probably float the high silver and flux combo all over the top of the trouble area because it is runny, and then switch to the 15% silver alloy brazing rod to cap it because it will build up a patch better. Bleeding the nitrogen through the tube while I heat it will eliminate any oxygen in the line that could allow any residual hydraulic fluid to catch fire, and prevent oxidation and pollution on the inside of the pipe. My first challenge is a bit embarrassing, as I attempted to bubble gum the leak first, so I will have to get the epoxy patch off of the area and get it back down to clean metal. I will document what I do and report back in a day or so.

 

[RickB]

You'll be fine.

 

[TractorGuy]

https://www.stainlesssteelfittings.com/47305_SAE_080101_Flareless_Compression_Fitting_p/47305.htm

 

[etpm]

I highly doubt you will get enough of the oil out of the tube to not have a film where the repair is going to be. Is there any way you can wash the oil out of the repair zone? Maybe squirt some cleaner through the crack after you have blasted most of the oil out and then blast nitrogen through again to blow the cleaner out? I too use air/acetylene for soldering and brazing copper pipe. Get it hot fast, get it brazed soldered fast, and then get the heat away. That way the flux doesn't get used up. I'm sure with your experience you will make a good repair.
Eric

 

[jaxs]

I totally indorse your choice of using tools and techniques you have experience with. Before getting underway,I'd like to offer food for thought. If the line is subjected to vibration/movement during normal use(what part of a tractor isn't) the heat-cool cycle will make it more brittle and pron to cracking. To slow down cooling and lessen the effect I suggest emediatly wrapping joint with your flameproof shield normally used to protect combustables during brazing/welding. To enhance and futhur slow cooling,a finger size rod heated dull red by an assistant and standing by ready to be wrapped with joint. Certainly not a cure-all but every little bit helps. Truth be known, mfgr's failure to properly treat line might be why it cracked.

 

[Boss 302]

Yes,
i\It can be done, if the line is split brill a very small hole at each end of the split and it can be brazed.