In the main transmission oil filter assembly, which component provides an alternate oil path when clogging is detected and includes an indicator button?

• A. Check valve
• B. Bypass valve
• C. Pressure relief valve
• D. Return valve

Answer: (B)

The bypass valve is the part that creates an alternate oil path when the filter starts to clog, ensuring oil can keep circulating even if the filter can’t pass it efficiently. As the filter element collects debris, the pressure across it rises. When that pressure reaches a certain point, the bypass valve opens, routing oil around the filter element so lubrication isn’t interrupted. The indicator button is often part of this assembly, popping out or signaling to show that the bypass path is active, which alerts for maintenance. The other valves aren’t designed to provide a secondary flow path around a clogged filter: a check valve only blocks reverse flow, a pressure relief valve controls system pressure, and a return valve handles oil returning to the reservoir, not the bypass around a clogged filter.