1998 E-One Ford Pumper

The brakes pads are below 50% and the brake drums have lots of heat cracking, this is on the front and the rear. The lighting in the compartments on the rear of the truck is missing lights and some are not working. The relief valve light is on all the time, it was working would need to fix the switch. The ok to pump and pump in gear lights in the cab at the switch did not work. 3. the ok to use the throttle light on the pump panel did not work. 4.All the pump panel discharge gages will need to be replaced. 5.The primer did not always work when I tried to operate it.  6.The drain valve