J.R.

30 years of getting dirty hands and leaving finger marks on the bottom of the tailgate through refusing to try a pointless piece of rubber. My Yeti has a recessed finger grip in the tailgate bottom but inside of the sealing strip so always clean.

Ain't that the truth, you can count on it being one or the other and never anything inbetween!

You can take that as a no!

A USB camera is peanuts from AliExpress. Might as well get a USB microscope at the same time!

A/C condensors are incredibly robust compared to the engine coolant radiators or intercoolers, they have to be because their rated pressure is 10 bar and the test pressure will be several times that. In my view they really dont need protecting like the other 2 heat exchangers do and them being in front of the others protects them. I rebuilt several cars with hard frontal impacts, front panel, wings, inner wings etc replaced, one had an AC condensor bent like a banana but just in case I depressed the Schrader valve before disconnecting it to throw away and it was still holding pressure and its integrity remained even after I had portapowered into submission to fit back on the new mountings. Corrosion will do for them though.

In which case I am wrong and it certainly sounds like it is the problem. Given I cant recall what I did yesterday I was foolish to put forward a memory from 15 years ago that may well have been my imagination, it will be interesting to learn if the union on the new pipe rotates & if so how freely compared to the leaking one.

They will compound & polish out but make them do it or negotiate a good discount. Its good that they have let you know in advance. Definitely bird lime damage.

So from that are you extrapolating that the law (what law?) will be updated and that insurers will refuse to indemnise policyholders whose "driver assistance systems" may have been worked on but not caibrated (as if they would even know) or where the driver has switched a system off "which doesn't switch it off"?

I know that you cannot be the only one to change gearbox oil because I also have done so in the past

I dont have a recommendation other than to steer clear of the Scottish Borders Good luck with finding someone competent, it looks like you have perfected what questions to ask & how to rule out those garages who don't understand.

The union is solid with the pipe and does not rotate.

The top hat seal will leak unless its pushed very hard onto the pipe until you feel it "click" into position, once there its very hard to remove, your connector does look like its the O ring type but I would try forcing the top hat one on, there are a couple of youtube videos somewhere and maybe one of them will give a close up of the pipe end. If yours is definitely the O ring type then it will be a 1.8mm cross section, they can leak where there has been movement, your new slave may be out of tolerance, a 2mm cross section O ring gives a much better fit & seal but you will have to measure with a vernier because all but one of my O ring sets has 1.8mm csa ones but the contents list describes them as 2.0mm. Finally I had the same problem on my MK1 Octavia after main dealer geagbox warranty work, being in France and having bought it from the original UK owner there was no way of me getting them to sort it, in hindsight it may have been the top hat seal not clicked into place, took me 15 years to learn that!!!! I resolved it by wrapping 2 pack epoxy putty around the joint, not to seal it, I knew that it could never do that but I had found that it didn't leak if pushed further in with hand pressure or it may have been pulling it back, I cant recall after 16 years but I rigged up something to either push or pull to stop the leak & then moulded the putty around it to maintain the position. A bodge but I had no choice at the time, it never leaked again though! Try a top hat seal properly fitted, if not compatible try a 2mm csa O ring and/or pushing/pulling to see if the leak stops & then do something like I did, alternatively another slave cylinder is cheap enougha nd easy enough to try. Next week I have to remove the whole 4x4 transmission to replace my concentric slave cylinder which is drawing air into the system, the new plastic one has is made in 2 parts with the same O ring joint but inaccessible within the bellhousing, I think it is that which is the cause, be thankfull you can replace yours easily!

Where I live its free draining chalk & goes down a very long way without hitting blue clay or bedrock, they have found WW1 tunnels after 90 years at down to 36 meters deep and there was only water in the lowest levels, I am amazed that my own cellar has never had any water rising even after the biggest storms ever. However I will be moving to a completely different area, as yet unknown so I will have to look carefully at the soil conditions or be very carefull with the construction. That photo looks real scary!

So its not the differential oil but the oil in the front Haldex coupling? I didn't know that they existed until I googled VAQ. Does the proper differential share the same bathwater as the gearbox?

There is, only change the filter when it needs changing, easy to judge by the reduced blower output. Air filters will last for 100000kms in the worst of conditions and still not affect the vehicles emissions or fuel consumption, it has been a homologation requirement for close to 30 years, annual inspection and dusting off combined with an obsessive scrutiny of fuel consumption meant mine remained on my vehicles far longer than that. The cabin filters are a different story but deffo havn't needed changing every 12 months/8K miles.

Only sounds like? Turning a system off does not turn a system off I suppose if you are tired & decide to have a sleep leaving the vehicle to look after itself & a driver assistance system is not working & you kill a class of infants waiting for the school bus then your insurers might look to reduce their liability. Thankfully I will never be faced with that moral dilemma.

So far with one exception at the hospital in the early days of the pandemic I have managed to avoid putting that rubbish anywhere near my hands. Dermatologists are going to have a field day. After all, unless you had some something really stubborn soiling your hands you would not wash them in petrol or paint thinners would you?

This was the cheapest on Ebay, £55 at the time for my Yeti and was excellent quality and very well packaged. https://www.ebay.co.uk/itm/401004968172?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

I noticed that the stub which protrudes for the bleed block to connect to was very wobbly, I bodged a tywrap retainer to pull it all up tight & stop the bleed block from moving around. When I secure the new cylinder to replicate it being bolted in place & try to move the stub on that there is no movement in the joint, I think the old one has been shaken around over the years and developed movement which in turn has rubbed against the O ring seal. I will hopefully know next week when I remove the old one. I may have spent €320 on a clutch & DMF for nothing but I wasn't going to not replace it while the gearbox was out.

The new clutch kit arrived today, below is a photograph of a new old stock genuine VAG part concentric slave cylinder with beside it the new and enhanced user experience plastic one from the kit, both are Luk manufactured parts, my vehicle has a plastic one fitted from new, until now I could only see the stub of the connector external to the bellhousing. Now I have a good idea what lies within the bellhousing there is no prize for guessing where an air leak might come from

The mistake made is the opposite of that, you would have to be absolutely determined to drain the Haldex instead of the diff, it is possible that the OP may have drained the diff and topped up the haldex though. If there is noise the OP should stop driving and check carefully, "more noise" does not sound encouraging.

Spray foam is very easy to control once you graduate from the aerosol type cans (which in my experience can rarely be re-used and the trigger will often stick full open covering you and the job) to a pro gun canister type. With a pro gun you can control the flow from a bead like a strand of cotton to full bore and once you are used to the expansion ratio of the product you are using you can create a very smooth flush job with no excess, when the regulating needle is screwed fully home the stuff lasts for years unused & the gun will work straight away. Its my bodging tool of choice now and I use several different low expansion adhesives far more than foams these days.

For all my "I am 100% certain I have resolved the problem................." optimism I have been kidding myself, the problem remains and has progressively worsened. I will be changing my clutch, DMF and concentric slave cylinder next week, after 3 months of trying everything to avoid pulling the 4wd transmission unit out I no longer have a choice as I have to bleed the clutch after every short trip into town, a 100 mile round trip involved losing the clutch on the way & having to bleed it, the same on arriving at the destination and once again during the return leg. Air is getting in at the lowest level either the concentric cylinder or at the bleed block O rings (which have been changed for 2.0mm dia cross section from 1.8mm) but there is zero fluid loss, not even a drip I am really hoping that not only will this finally cure the problem but that I will be able to find what exactly has been happening, the only remaining theories that I have are axial oscillation from a worn DMF and/or a fractured preload spring on the cylinder. The air never rises above the bleed block as it sits in the vertical bore under the bleed valve, clamping the flexible line always results in a solid pedal, but beware, only push the pedal with your fingertips or you will bend or break the plastic master cylinder pushrod and have the pleasure of yet another master cylinder change. So the only thing that I can be conclusive about for now is that the air must be getting in at a lower point than the bleed valve, I hope once everything is removed I will find out where, how and why.

I will be changing my clutch, DMF and concentric slave cylinder next week, after 3 months of trying everything to avoid pulling the 4wd transmission unit out I no longer have a choice as I have to bleed the clutch after every short trip into town, a 100 mile round trip involved losing the clutch on the way & having to bleed it, the same on arriving at the destination and once again during the return leg. Air is getting in at the lowest level either the concentric cylinder or at the bleed block O rings (which have been changed for 2.0mm dia cross section from 1.8mm) but there is zero fluid loss, not even a drip I am really hoping that not only will this finally cure the problem but that I will be able to find what exactly has been happening, the only remaining theories that I have are axial oscillation from a worn DMF and/or a fractured preload spring on the cylinder.

He connected the battery or the jumper pack backwards (reversed polarity) the diode would then have conducted in the reverse bias direction and in the absence of a current limiting resistor the current would quickly have destroyed it. I am shocked to learn that it is there and that there is presumably no reverse bias overcurrent protection, a design fault if my hypothesis is correct and a worrying one if an incompetent or careless mechanic or auto electrician can effectivelt write off a new vehicle in the blink of an eye, it also paves the way for malicious damage or perhaps dodgy insurance claims if someone has for instance run the engine without oil. I would say that the auto-electrician mortally damaged the diode but it hung on for the 3 days before finally succumbing to its wounds. Editted, I think that I have misused the term reverse bias, in normal use the diode is reverse biased current wants to flow to the negative side but cannot, if the voltage rises above a threshold then it becomes damaged & will conduct in the reverse direction.