[Purdy Swoft]

Check the brake pedal rod. If the service brake shaft isn't set up just right the plunger end of the pedal rod may not be moving backwarss far enough when the brake pedal is released. The service bulletins calls for a 1/16th gap between the plunger end or the brake pedal rod and the inside rear of the center crossmember. If this adjustment isn't correct it will have a big effect on how the brakes work , as well. If this checks out wrong the brake rods will all need to be disconnected. Adjust the brake pedal rod clevis so that the pedal is at the top of its travel with a 1/16th gap between the pedal rod end plunger at the rear of the center crossmember. Then adjust each service brake rod clevis end so that the clevis pin will just enter with no slack or free play in the brake rod. This will probably give brakes that you didn't even know that you had. If the brake light switch still doesn't function replace the switch. I've never had much luck with repro brake light switches. Berts usually has Nos or good used switches that work, I've got several from Berts in the past.