Seized Brake Lines

[Lewis's Friend]

Hi All

I'm currently doing a brake refresh on a B12 Subaru Legacy GTB. I want to put new brake lines on to replace the rubber flexi pipes, but the unions to the hard lines are seized absolutely solid.

What is the best way of getting these undone? The union nut is 10mm, but is going to round off quickly using an open spanner. I have soaked everything with plusgas etc but it is way too tight.

I don't mind destroying the flexi pipes, but need to keep the hard lines (which carry the 10mm nuts) in one piece.

Any advice would be great...

[stevieturbo]

Hard lines can be replaced too, sometimes destruction is inevitable.

If you have room to get them in, this type of vise grip is very good for such things though.

[CrutyRammers]

As above really. I've just taken some off my MGB project, and there was simply no way of getting the unions off while attached to the car. Clean it as best you can and try, but be prepared to replace the hard lines.
Brake pipe is cheap, fortunately, it just can be a bit of an arse to replace.

[Lewis's Friend]

Thanks for the feedback - sadly, I think you've confirmed what I thought...!

[Dave Brand]

If the nuts are seized onto the rigid pipes they are probably steel. In my experience what PlusGas won't free off ain't gonna move - although you could try heat, not a thing I like doing around brake bits.

Look on it as an opportunity to replace steel brake lines with Cunifer!

[andyiley]

Use copper rather than cunifer, the difference is not worth the difference.

[S0 What]

Propper brake nut spanners help IF they are a decent make?

[stevieturbo]

S0 What said:

Propper brake nut spanners help IF they are a decent make?

Not so much, the fact they are open they will still flex.

The strongest grip will be the Vise Grip type tool I posted, or if you cant get that around it, normal decent sized Vise grips

[Mr2Mike]

andyiley said:

Use copper rather than cunifer, the difference is not worth the difference.

No, use Cupro-nickel (e.g. Kunifer) rather than pure copper every single time. The price difference is more than worthwhile. Copper work hardens very easily.

[andyiley]

If copper is attached properly & securely so that it does not flex then it does not work harden, but it is significantly easier to work & therefore make fit properly to enable it to be correctly secured and therefore alleviate the issue of possible work hardening.