What is the maximum movement allowed for the push rod during testing?

The maximum movement allowed for the push rod during testing is typically defined as not more than 1 inch when pulled. This standard is crucial because it indicates the condition of the brake adjustment within the air brake system. If the push rod extends beyond this limit, it may signify an adjustment issue or that the brakes are out of specification, potentially leading to ineffective braking performance. A push rod that moves more than 1 inch when pulled could indicate that the brake shoes are excessively worn or that the brakes require adjustment.

Understanding this limit helps ensure that the braking system operates effectively and safely. It's important for drivers and technicians to be familiar with this standard to maintain optimal vehicle safety and performance on the road.