Some of the 850 service manuals come in pdf format. I'd like to be able to post a pdf when responding to a thread. Max size is 1MB. Is that possible? BTW it is allowed on all the other Volvo sites.

Just post a link.

My question is why can I paste a picture that weighs 500K and not a pdf. That's doesn't make much sense for me.

Maybe because the software doesn' support PDF's.

So use a free PDF hosting website and post the link.