hi folks, got a 07 reg fiesta and front caliper drags, got a new caliper and hose as old hose is rusty

trying to undo the brake hose from brake pipe in the wheel arch, but just won't turn, been spraying with Plus Gas, WD40, and Crackit freeze spray but still not moving, 

was wondering if i can undo the hose from the brake pipe nut by using the flat sides of the hose union

any advice out there

Yes.  It's more hassle, but theoretically you can unscrew the hose from the union if the union has seized to the pipe.

Just be careful not to twist the solid pipe at all.  Once you've twisted it, it's game over, it'll need cutting off and a new piece of pipe will need grafting in.  Doesn't have to be miles of pipe, just a few inches is fine.

thanks, thats the worry, that the pipe twists

keep spraying in plus gas to release the threads

Use a proper flare nut  spanner. They don't put pressure on just 2 opposite flats, which slightly squashes the union which causes the issue you've got. It'll be an investment.... Halfords sell 'em. Check what size your flare nuts are tho' before buying one. 

just an update, I took the plastic wing liner off and there is another brake pipe connection there and its rust free.

I got the extra brake pipe £11,  much easier 

I made up a small length of brake pipe with a connector one end and stopper the other, so when i undid the connector "under the wing liner" i put my small pipe on giving me time to fiddle and get everything sorted with out losing to much brake fliud

so rather than buying lots of Plus gas etc, just take wing liner off and go back to the next connection

just to update, the fault I had was the brakes were blinding on the discs, (new disc's & Pads fitted in the summer)

once i gotcalipers & hoses/pipes changed, i checked the old hose and found the hole though the hose was almost completely blocked, the metal connections must have rotted