When changing pads do brakes have to be bleeded and if so how 1987 Mark7?

As long as the hydraulics are not opened, you do not have to bleed the system. When changing the brake pads, you can compress the caliper pistons back into the calipers without opening the hydraulic portion of the system. However, you may want to crack open the bleeder screw on the caliper to make it easier to collapse the piston, but even in that case, the system should not require bleeding.