Braze a hydraulic line

JRaf

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Equipment
L245DT
Oct 15, 2019
47
6
8
Los Olivos CA
I pulled the top off the rear hydraulic case on my l245dt and fixed what was inside only to realize later that I'd created a leak in the joint where the high pressure line attaches to the loader block. (See pics). Sorry if my terminology is wrong. But I'm thinking I can braze the joint with flux and (15%) silver brazing rods. Does this sound correct? Thanks for the help.
 

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Blondie70

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L2501DT('18)L2501('15)
Aug 6, 2016
256
1
18
Poplarville, MS
Sounds like a good plan to me but the heat could damage any closeby o rings, etc....."?????? You will have to know about that first.
 

dlsmith

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Nov 15, 2018
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If it was previously brazed with a brass alloy rod, which is what it looks like, that is what you will need to use to re-braze it.

Are you able to remove the assembly to repair it?

You are going to need to get the block the line goes into pretty warm to get the brazing rod to flow and fuse.
 

JRaf

Member

Equipment
L245DT
Oct 15, 2019
47
6
8
Los Olivos CA
I can split the block apart and take the line off the sump(?) then I’ll take out the o-rings, clean off the rust and paint, and I should get a better look at the joint. But if it is brass wouldn’t silver solder stick? Out of my element here. Thanks again.
 

lugbolt

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ZG127S-54
Oct 15, 2015
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If it was originally brazed, use a brass rod to repair it and nothing else. They are easily found at most hardware or farm supply houses. I don't use them often but I keep a few brazing rods handy just in case they're needed. They come in REALLY handy from time to time; can repair all kinds of stuff. There's a 351w Ford block in the other race car that had an "oops" (broke rod, threw it out of the side of the oil pan rail)....brazed up the hole and it's still going strong, and nary a leak.
 

North Idaho Wolfman

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You can use silver (hard) solder, (not the same as copper pipe solder) as it will work with both the steel and the brass, but the reason they don't use it is it's hard, no vibration flexibility.

Like others have said, stick with the brass rod.
 

JRaf

Member

Equipment
L245DT
Oct 15, 2019
47
6
8
Los Olivos CA
Ah, that makes sense. I was thinking the silver rod would melt at a lower temp, but it makes sense that you'd need more flexibility. Actually the engineering of the system is curious. The block which has inlet and outlet pipes braised on either side also carries two hose ports on top (that go directly to the FEL valves). But the block isn't fastened to the trans case in any way, it simply floats, suspended on the little pipes. I suspect the system was grafted onto the original tractor design (though it's in the parts book and WSM). Maybe it was poorly installed by a dealer? Of course if it took 40 years to break, and only after a clumsy bit of repair by me so I guess that's not bad.
 

motorhead

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Equipment
2009 B3200, 2007 Dodge/Cummins powered Ram 2500 395hp
May 17, 2012
415
21
18
Atascadero
Silver solder would be good. Chances are that it was "Furnace brazed". That's where the parts are clean and lots of time a copper paste is applied to the part and then put into a brazing oven.

I strongly suggest removing it, thoroughly clean the part with a de-greaser like Castrol Super clean or Purple power. MAKE an alignment mark on the square piece and the tube that line up with each other so if it shifts at all when re-brazing it, it can be straightened. If you think it will come apart by heating it up enough, that would be better so you can really get in to the joint area and get rid of all oils. Use some wet or dry paper in the hole and on the line to clean any debris off so the joint goes back together cleanly and seals well.

Let us know how it comes out.
 

lugbolt

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ZG127S-54
Oct 15, 2015
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generally speaking the steel parts that I do some brazing on require them to become dull red for them to be properly brazed using flux-coated brazing rods. For most mild steels, this is around 1500-1600 deg F.

Silver brazing takes place (usually) at 850 or so. It's an easier operation but as said, it is not tolerant of much vibration and movement without cracking. That's why OEM uses brass or an alloy of it for joining the two tight-fitting pieces together. It works and it is strong.
 

JRaf

Member

Equipment
L245DT
Oct 15, 2019
47
6
8
Los Olivos CA
Okay, not sure if anyone's interested but I feel like I should finish off this thread. I split the block and,with some difficulty, removed the solid hydraulic line that runs from the pump down under the brake pedal and up over the trans to the sump. I blew it out, cleaned it, and got all the paint off the joint that I thought was leaking.
But there was no evidence of a crack or even a piinhole in the old brazing. There was also no rust. It was, to my eye, a beautiful (forty-year old) joint. I took the assembly to a friend who has an acetylene torch. He thought it looked perfect too and suggested it might be one of the nearby o-rings leaking, not the joint. I'll admit I was losing conviction but we heated it up and rebrazed it (with a brass rod) anyway. It wound up being a bit of a mess.
On my way home I stopped at the Kubota dealer and bought new O-rings. I got the assembly home, reinstalled the line with the new rings, topped up the hydraulic fluid, pushed manure around for an hour, hauled firewood, dragged a pasture. No leak. None. I now believe it was never the joint, but was that worn O-ring where the fluid managed to somehow migrate under the pipe.
The leak is fixed, at least for the moment.
 

redfernclan

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Jul 18, 2014
155
4
18
Sweet home, Oregon
Thanks for finishing this up, I was wondering. Not sure if this is the "proper" way, but back when I worked in a saw mill as a heavy equipment mech, we would lose hyd pipes on our loaders like the one in you pic but about 2 to 2 1/2 inch in diameter. Didn't allways have a new one on hand so I would braze over the top of the silver solder. Not just sweat soldering it, I would lay a fillet of brass over the sweat soldered joint. We started noticing the the pipes I had brazed were lasting longer than the new ones. You can get creative in a pinch.
 

chim

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L4240HSTC with FEL, Ford 1210
Jan 19, 2013
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Yes - thanks for getting back with the rest of the info. I was reading the thread and wondering about the outcome.