A car with an LSD should NEVER be used on a MOT braking machine

.
Very easy to screw the diff up completely

, ALWAYS insist on the machine they put inside your car, be it electronic or the mechanical swinging one.
As Pon says, them hoses are tested at stupid pressures but it could be something simple like it was kinked badly when fitted and has gradually been degrading until Bang

.
Like you James I got totally sick of spending money on what shouldnt have needed spending on, so I decided to get rid and buy something that doesnt need fixing every weekend. The Audi has been great upto now

, but miss the turbo rush
Will get something worth spending money on when the time is right