A Fan Pilot Spacer, also known as FPS, is a small component located between the fan pilot bearing and the fan clutch drive plate in heavy-duty trucks. Its primary function is to ensure proper spacing between the two components, which prevents excessive heat buildup that can damage the bearing or clutch. The spacer is typically made of durable materials such as steel or aluminum and must be precisely machined to fit snugly in its designated location. Without a properly functioning FPS, the fan pilot bearing and clutch could fail, leading to engine overheating and potential damage to other components.