It seems that I have too much free play / slack in my brake caliper. The arm on the caliper moves full travel without setting the brake. I think there is a way to remove the slack from the self adjusting system but I have no idea how to do it. Can't find any explanation on what happens inside the caliper when you use the P- brake.
Girling single piston caliper. Car s/n 9193.
This came about after I resealed the calipers. The car had been inactive for 18 years