I ordered Meritor Clay Grease should receive today. At some time I saw a clear simple way to lube the slack adjusters/disk brakes on the net. I cannot find it now. It showed pictures of the brake assembly. and how to lube. This was great for simple minds.
Thanks for your help Karl
Here's an extract from the Meritor PowerPoint covering caliper lubing, and two extracts from the manual covering the same thing.
I believe the complete manual is either in the Forum files or on Barry Beam's site. (Too big to download here.)