Was driving down the highway on Friday when the brake pedal became mushy, the red brake light came on, and I couldn't stop. Downshifted to 1st gear and pulled the handbrake which allowed me to come to a stop. Brake fluid is definitely leaking out of the passenger rear hose area.

 

My first step is to find out what size line it uses. I am seeing 1/4" or 3/16". Does anyone know what it would be for a 1997 Legacy Outback Wagon?

Is it the rubber hose or the metal line?

 

The metal lines like to rust out above the fuel tank.

The easy thing for those is to cut the line where it goes through the floor under the rear seat and run a new 3/16 line along the frame out to the wheel.

Is it the rubber hose or the metal line?

 

The metal lines like to rust out above the fuel tank.

The easy thing for those is to cut the line where it goes through the floor under the rear seat and run a new 3/16 line along the frame out to the wheel.

 

That sounds about right. 3/16 is it.

My '03 has metric fittings with I think at least some bubble flares, not sure...

3/16 line works fine but you have to swap over the old ends and reflare or find metric line when attaching to an existing female connection.

I'd highly recommend using the cupro-nickle line to replace it. It's a bit more expensive but much easier to fit into place, harder to kink, and will never rust out again.

 

When you go to remove any of the line nuts on the failed line, just cut the line off close to the nut and use a 6 point socket on the nut. If you try to undo them with a wrench they will round over. Once it's off, you can drill through the stub of line left in the nut to clear it out and re-use the nut on the new line.

 

A reasonable double flaring tool can be bought for $40, a roll of 3/16 cunifer line for $25, and you re-use the nuts. A pair of brake line bending pliars can be handy for the tight U bends where the rear lines attach to the hoses.