How are the first two stages of the Telma Transmission Retarder operated?

The first two stages of the Telma Transmission Retarder are operated at off throttle, meaning that the vehicle's accelerator is not engaged during their operation. This is essential because the retarder is designed to provide additional braking force by using the vehicle's transmission system to create resistance without relying on the vehicle's traditional braking system.

During off throttle conditions, the transmission retarder uses the engine's natural resistance to slow down the vehicle, enhancing control and reducing wear on the brake components. This operation is particularly important during prolonged downhill driving or in situations where maintaining a controlled speed is necessary without overheating the brakes.

In contrast, using the retarder when the vehicle is at full throttle or with the transmission in neutral would not effectively harness the retarding forces, which is why those conditions are not suitable for its operation. Similarly, while the retarder is beneficial during deceleration, it does not solely rely on that phase, as it can be engaged at off throttle states for maximum effectiveness.