I've been troubleshooting a leak and the dye does not appear anywhere forward of the firewall. My sniffer also doesn't detect anything. The sniffer does go off when I put it in the center vent. Has anyone replaced the evaporator in an xjs? It will be a winter project for sure.
does anyone know of a process to seal the inside without removing it? At least when I have the dash out I can fix the demister flaps to.

 

Winter job alright! In a heated garage. All the dash and tunnel has to come out, then the A/C -heater unit, then you can do it OK. 4 day job, quite doable but just needs patience and care, labelling everything you undo. Needs two to remove the unit. And you can clean up all the earths, fix insulation, renew body grommets etc etc. I have done this for my rebuild and so have lots of guys on here. If and when you need details, just post.

No reliable way of sealing the thing otherwise, there are (I have heard) bodge-type gunk you can put in to try, might work, might not, never tried it, never met anyone who has...

Greg