How to undo seized brake-line to hose nuts? Any ideas?

[eeedelli]

Hi all,

I'm at my wits' end with this one!

I've had to replace the rear calipers on my 740 estate. All went well until trying to remove the old hoses from the brake lines. The nuts are absolutely solid, having been on there for 32 years.

They also appear to be brass and even the use of a proper split-ring brake spanner resulted in turning over the corners.

I've since bought a special locking wrench (4LW size - https://www.irwin.com/tools/locking-...cking-wrenches) which is designed to clamp on to the alternate triangular faces of the nut so as to avoid slipping over the corners and it doesn't slip but I still can't shift them.

I've tried heating the metal ends of the hoses to try to break any rust seal and tried to get some 'plus gas A' up there (though tricky because of the angle - hose pointing downwards) but to no avail. Even putting a lever between the grips and the 14mm spanner on the hose just ended up trying to twist the bracket.

I had a similar problem with one of the O/S/F pipes when replacing calipers there a year or two back, so I had to dismantle back to the master cylinder and take it into my local motor factor who made up a complete new pipe. It wasn't too bad there, as it was the shortest run. However, that's absolutely the final resort on the rear as, with split diagonal circuits, both pipes individually run the entire length of the car and would be a nightmare to remove and replace.

Does anyone have any ideas?

Ta,
David.