brazing a hydraulic line

[coloradotrout]

Lower line disconnected. I used compressed air to clear the line of most fluid. The other end is attached to the tractor. I think I can get a torch and brazing rod in position.

Is mapp gas hot enough?

The leak is tiny and somewhere around the perimeter of the line to fitting connection. I watched for minutes and couldn't exactly pinpoint. At just idle it produces a drip once a minute or so. Under load - using the FEL, for example, it leaks much more.

 

[TMGT]

It needs to be clean, you'll have to clean out the inside with solvent and keep oil from getting to the joint. Otherwise it can wick the oil up into the joint and could male things worse.

Once cleaned inside and out with solvent (brake clean, acetone) heat it with the torch to cook any remaining junk out.

Sent from my SM-S921U using TractorByNet mobile app

 

[coloradotrout]

It needs to be clean, you'll have to clean out the inside with solvent and keep oil from getting to the joint. Otherwise it can wick the oil up into the joint and could male things worse.

Once cleaned inside and out with solvent (brake clean, acetone) heat it with the torch to cook any remaining junk out.

Sent from my SM-S921U using TractorByNet mobile app

I should be able to clean up the fitting and an inch or so in the line. Have to get at it from the fitting. Spray some carb cleaner or work a pipe cleaner in there. I don't want to heavily contaminate the fluid that is further down the line.

 

[etpm]

The problem you face with heat is not that MAPP gas is not hot enough, the problem is if you can heat the joint up fast enough. You have a big steel puck to heat up. You need to get it hot fast. A small but hot flame isn't going to be enough. You could use a weed burner to heat
the puck up fast and then go in with the MAPP torch to do the brazing. I suggest you practice on a similar sized piece of steel first to get your technique perfected. Or just go ahead and prove me wrong by just trying your MAPP torch on the joint and being successful. Let us all know how you do.
Eric

 

[coloradotrout]

The problem you face with heat is not that MAPP gas is not hot enough, the problem is if you can heat the joint up fast enough. You have a big steel puck to heat up. You need to get it hot fast. A small but hot flame isn't going to be enough. You could use a weed burner to heat
the puck up fast and then go in with the MAPP torch to do the brazing. I suggest you practice on a similar sized piece of steel first to get your technique perfected. Or just go ahead and prove me wrong by just trying your MAPP torch on the joint and being successful. Let us all know how you do.
Eric

The puck is about 2" in diameter and hollowed out for the fluid and 3 bolt holes. I need to settle on which brazing rod to buy. The lowest temperature that will hold is what I'm thinking!

 

[etpm]

The puck is about 2" in diameter and hollowed out for the fluid and 3 bolt holes. I need to settle on which brazing rod to buy. The lowest temperature that will hold is what I'm thinking!

Good luck.
Eric

 

[jwmorris]

This is a brazed joint.

If it is leaking at the joint between the puck and line, you will indeed need good luck, just "going over it".

You will need to heat and separate the two to properly prepare the two surfaces for a successful bond.

We all already know there is oil between the two now, that will ruin any chance of seal once heated, or you wouldn't have found that spot to be the source of the leak.

 

[coloradotrout]

This is a brazed joint.

View attachment 4419919

If it is leaking at the joint between the puck and line, you will indeed need good luck, just "going over it".

You will need to heat and separate the two to properly prepare the two surfaces for a successful bond.

We all already know there is oil between the two now, that will ruin any chance of seal once heated, or you wouldn't have found that spot to be the source of the leak.

Thanks. I can try compressed air all around that area and some carb cleaner with compressed air to see if I can get it clean. The leak is tiny. At idle I get a drop every minute. Under load it's a drop every 10 seconds. The scratches you see in that photo are from a knife to get my JB weld off. The JB was tight against the line, but not so much near the puck. That suggests to me that the leak is right at that joint. Plan B is to clean it up, and lather on another JB weld. I guess plan C would be to replace this with a hose. I have another puck from another engine and that was has a screw on fitting.

 

[jwmorris]

The JB weld would probably have a better shot if you intend to leave the joint together. If you can keep it from vibrating around it might last longer.

The oil in the joint, likely won't come out until you begin to heat, then it will keep wicking out and ruining any chance of a good seal. Why it needs to come apart to he cleaned.

 

[coloradotrout]

Bought these. Will test on scrap. Doubt my mapp gas only torch will melt.