I am going to replace my timing belt this weekend and I am planning on replacing the cam seals at the same time. Bentley recommends special tools for the job. Are these tools absolutely necessary or are there other tools that can be used? Is there some sort of write-up on the subject??

 

I can't speak for the A4, but I've changed them on other cars using a screwdriver and the little plastic hang tab that individual sockets are hung on for sale (know what I'm talking about?) - I used the plastic piece as a shield to try and prevent any damage to the area around the seal. What you have to be very careful of is to not score the metal around the seal or you could create a seepage problem that may only be fixed by replacing the damaged part (ie, the cam, or part of the head that encases it). I got through fine, but it took a LONG time because I was working as if I was operating on the baby Jesus. If there are special tools available, I'd look into at least renting them - if you screw up you could be into a lot of money for repair work.