Octavia MkII estate tailgate latch

I thought i'd share my 'learnings' after having trouble with the tailgate latch in my 2010 Octavia Scout  MkII. The tailgate latch or the button above the number plate started malfunctioning about a year ago, making whirring noises but failing to release the tailgate.  We have a dog who is transported to local areas for walks and I am constantly using the boot for various reasons, so a non-functioning latch was a true PITA.

A YouTube vid showed someone spraying CRC/WD40 into the latch mech so i tried this - unsuccessfully, but strangely enough (as intermittent elec faults can be) it suddenly decided it would cooperate. In the meantime I'd purchased a  replacement latch that sat idle until it began to refuse admission again about a month ago. So ... I fitted the 'new'  latch - no change, same prob. To prove i didn't have TWO latches with the same prob I fitted a latch from a friend's Mk1 that I knew was working - no go, same whirring, then a pause, then another short whir ... but no latch release.

A visit to my ever-helpful auto elec where he identified that the whirring noise was coming from 'elsewhere' - very difficult to pinpoint the location as the sound resonates in the entire tailgate. Long story short, I discovered that there's a 'hidden' mechanism  under the boot ledge cover, an electric servo motor that operates a lever, which then operates the latch release. you would NEVER know this from looking at the latch - it has an electrical connector that makes you think it's the entire release mechanism, but the connector is obviously only to a sensor that tells the CPU when the boot latch is open or closed. 

My symptoms were an initial brief whirring sound , a short (maybe 1 sec) delay and then another short whirring sound from the latch area, but a failure to release the latch. Once I had the servo assembly out (two Torx T45 bolts and one elec connector)  I could use a remote battery in the workshop to test the mechanism. Mine was covered in hair from previously mentioned dog. A spray with CRC/WD40 and a good external clean by applying current to the unit to hold it 'open' and it seemed to function normally. I refitted it to the car and adjusted the latch position and it's been fine ever since. 

If someone had posted this info somewhere it would have saved me a lot of grief (and AUD$120 for the part I didn't need) so hopefully this will help someone in the future who recognises the symptoms in their own car. Pics attached.