Two technicians are discussing proportioning valves. Technician A says proportioning valves are designed to keep the disc brakes from applying before the drums. Technician B says that load-sensing proportioning valves sense vehicle load and adjust brake pressure. Who is correct?

Question

Quizplus · Accepted Answer

Technician B is correct. Proportioning valves regulate brake pressure to the rear brakes to prevent the rear wheels from locking up before the front wheels. Load-sensing proportioning valves are able to adjust the brake pressure to the rear wheels based on the weight distribution of the vehicle, ensuring optimal performance in various driving conditions. Technician A is incorrect because proportioning valves do not differentiate between disc and drum brakes, but rather adjust pressure to the rear brakes as a whole.

Two Technicians Are Discussing Proportioning Valves