What problem can arise from adjusting the master cylinder push rod incorrectly?

Adjusting the master cylinder push rod incorrectly can lead to brake lock-up, which is a serious issue in vehicle braking systems. The push rod connects the brake pedal to the master cylinder and is responsible for converting the pedal's mechanical force into hydraulic pressure within the braking system.

When the push rod is not adjusted properly, it may either be too long or too short. If it is too long, it can keep the master cylinder's piston partially engaged, which leads to continuous hydraulic pressure causing the brakes to bind. This binding effect can result in the wheels locking up during braking, which can cause loss of control and significant safety hazards.

On the other hand, if the push rod is too short, it may not allow sufficient travel for the master cylinder piston to build up the necessary hydraulic pressure for braking, leading to poor brake engagement rather than lock-up.

Thus, the main concern with incorrect push rod adjustment is the potential for brake lock-up, highlighting the critical nature of precise calibration in brake systems for optimal performance and safety.