XRAY - Model racing cars

I'm having some trouble with the rear brakes on my 2001 Saxo VTS 1.4 . We changed the rear drumbrakes and brakeshoes but because we didn't think the rear brakecylinders were broken we just kept the old ones. When we tested the brakes the stopping force was still to low but much better than in the beginning.


We then decided that the only problem could be the braking cylinders because this was the only thing which wasn't replaced. When we replaced these this and tested it you could hear the rear automatic brake adjuster do his thing (as it should do ) but when you pull the handbrake would feel and hear something, it felt like you snapped the cable or something. But it turns out you just reset the automatic braking adjuster because when you try braking after pulling the handbrake you can hear the "clicking" sound it makes when its adjusting the brake shoes.

Does anyone know how this can be solved because the adjuster mechanism seems in a good shape ?