I'm having a problem with my 2005 international 3200 school bus. the bus will drive forward without any issues but when its in reverse it feels like the parking park or regular brakes are holding. The bus will move if you give it enough throttle. The parking brake is air operated. Any ideas? thanks!
You may have a broken return spring on one of the wheels. My mind and laws of physics would lead me to believe it would be one the left side.
You could drive it on a road test then use a temperature gun to check the drum temperatures. They should be within 10% of each other on the same axle. Somewhere around 180-250 on the rear and not over 200 on the front.