166 Brakes G WARNING If the parking brake lever is not in the fully applied position, it automatically returns to the released position. The vehicle could roll away as a result. There is a risk of an accident. Move the lever into the fully applied position when parking the vehicle. Parking brake Trailer with EC brake system: when a trailer is attached, the parking brake actuates the trailer's service brake. Vehicle with trailer: check the parking brake when parking the vehicle X Press the top of parking brake lever : . While doing so, move parking brake lever : beyond fully applied position 2 into control position 3 and hold it.
During the test, the vehicle combination is only held by the force exerted by the spring- loaded brake of the tractor vehicle. The trailer brake is released. The vehicle must not move. X Apply the parking brake. Driving mode G WARNING The parking brake may not be sufficient to ensure that the loaded vehicles does not roll away on uphill and downhill gradients. There is a risk of an accident. In the test position, check whether the park- ing brake will hold the loaded vehicle. If the vehicle is not held, secure it using other meth- ods, e.g. wheel chocks. X If the force exerted by the spring-loaded brake cannot hold the vehicle combination, secure the tractor vehicle and trailer using chocks.
X Move parking brake lever : from control position 3 back to fully applied position 2 and engage it. Releasing the parking brake X Pull parking brake lever : upwards from fully applied position 2 and swing it up into released position 1 as far as it will go. The ! indicator lamp in the instrument cluster goes out. If the reservoir pressure in both brake cir- cuits is above 8 bar, the parking brake releases fully. If the ! indicator lamp in the instrument cluster does not go out, the reservoir pres- sure in the spring-loaded brake circuit has dropped below 5.5 bar and is too low. Secure the parked vehicle against rolling away by applying the parking brake.
The park- ing brake actuates the spring-loaded parking brake cylinder. You can find further information about the parking brake on the trailer in the manufac- turer's operating instructions. Applying the parking brake To tow the vehicle, you can also release the spring-loaded parking brake cylinder on the parking brake manually ( Y page 335). X Move parking brake lever : from released position 1 to fully applied position 2 and engage it. The ! indicator lamp in the instrument cluster lights up. Four-wheel parking brake The four-wheel parking brake couples the ser- vice and parking brake electropneumatically. It is only active when the engine is running