Handbrake failure after new caliper fitted

[Quattrodave]

Afternoon all,

I had a leaking OSR caliper on my 2007 4.2 FSI so took it to my local garage with a recon unit to change over, which they did no problem.

The issue arose when they went to re-engage the hand brake - nothing happened to either OS or NS calipers. They plugged in the old caliper and tried to get the handbrake to work but again nothing.

They called me and said they'd booked it into a specialist (ABtech in totton) who today have run a diagnostics on it and not identified anything. I've now just had to give the green light for them to look more into it and identify what's wrong and why.

Two things:
1. Does anyone have an idea what could have happened? Could, as my local garage have suggested, there been an internal fault with the caliper which has fried the parking ECM or could it be that my local garage, who aren't Audi specialists or even particularly high tech, have buggered something? Would I (read Abtech) be able to tell whether they'd done something wrong?

2. If it turns out that the replacement (warranted) caliper is faulty and has caused the ECM to die I will go after the supplier for costs. Aware that they will simply say bugger off and I'll have to go legal on them but it's looking like heading towards £1,000 to diagnose and repair a job that should have only cost £250 including the caliper!

I'm currently on day 5 with no car (and no courtesy car) and won't get it back until Thursday at the earliest so needless to say I'm livid at this moment in tim!

Thoughts & advice most welcome.