Hi, my car failed our equivalent of MOT due to unfven rear brake force, meaning right and left brakes too different. Do I need to adjust each brake individually or can it have something to do with the proportional brake valve thingy?
its only the brakes themselves, the valve only controls front to back.. check hard line has not been dented, otherwise it will be one side is out of adjustment. its common for the auto-adjusters to wear and not work. you also may have contaminated pads which might mean a new axle seal.
I would say the shoes are out of adjustment I would suggest adjusting both of them till they just touch drums then back them off one click each they should feel the same on both sides remove drums and check shoes are all evenly worn and serviceable first of course