Replacing the central locking boot lid actuator rubber boot
 

I did this repair yesterday. I am submitting this documentation in case it can help someone he future. I realise that there are probably other (and better) documented fixes on the internet but here is my effort nonetheless.

Attachment 22775

Improvements and/or amendments will be gratefully received and incorporated.

Thanks to all for being here!

So the orange actuator seal is an original C4 part?

Is the Bosch part (the spark plug boot) one you think is a viable alternative?
Have you tested it?

Is a seal made to the original design a candidate for 3D printing?

Sorry for so many Q's!

Yes, an original C4 part from my 1994 Audi 100q. Even the ones from a year later, as found in the two C4 A6 vehicles that I have, seem to be of a lesser quality than the orange boot.

As I mention in the PDF document, the Bosch boot failed after about a year of service in my A6 Avant. The rubber that it is made of is too soft (not stiff enough) and started to allow the rear hatch to lock when going over bumps on a warm day. :Confused: It hasn't split yet though. So, it seems that the rubber needs to be of a certain rigidity to work properly.

Yes! I think that it is a candidate. The TPU and the Ninjaflex that I have would both make seals of sufficient rigidity I believe...maybe too rigid...but I will have to make one to find out. +++

Did you by any chance try sourcing the orange boot new? Or would you have a PN?