The induction heater that I was looking at, simply to play with as it seems to only have a coil big enough for 1/2inch nuts, is something like

http://tinyurl.com/y77sbjqd

I understand it is critical that it is fed from 12 volts that can provide full current instantly so that the circuit is shocked into starting. Any clever power supply that ramps up gently when connected will blow it up. It produces eddy currents in the nuts and bolts that heat them up. Vaguely like a microwave oven concept?

It just looked interesting, educational and fun. I assume ones for freeing nuts and bolts on vehicles are hugely expensive. That was what was used on my Jeep to free the tracking.

It's done! I supported both the brake disc and body on axle stands as per the wiki BUT had turned the wheel full lock beforehand to allow more room for both heat and a sledgehammer.

Two minutes of 1800C heat from a brazing torch (using map gas not propane) with a heat mat and thin plank protecting the drive shaft gaiter and many large whacks from an 8lb sledge hammer followed by a drift and lump hammer. The bolt had rusted inside the casting, so it wouldn't turn at all (industrial air wrench/ 5ft trampoline leg extending a breaker bar). I cleaned out the casting, applied copper slip and bolted everything back together.

The air suspension only leaked when it extended about an inch into a pothole or went into off road height - I managed to drive nearly normally (more slowly and avoiding potholes) with minimal error messages and the orange suspension lights staying on by lowering the height of all corners by 25mm in the interim.

Thanks for all the help!
VV

good news but what a faff for just one bolt

Pleased to see that the "trampoline leg" is still the preferred solution  .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

Previous: L322 Range Rover TDV8 3.6 2008; L322 Range Rover TD6 3.0 2002; P38A Range Rover V8 1999

Congratulations.

Gotta wonder if a hex head setscrew (threaded all the way up) could be an acceptable substitute. P38 uses them in many places where I'd expect a bolt. Wondered why until first time I tried to shift one after many years of happy inter component marriage. Thread means it just screws out through the corrosion. With a plain shank bolt any corrosion expands filling the small gap between bolt and hole gripping the pair tight enough to make. Mr Loctite envious.

Clive

This is my weapon a 14 pound sledge