Mercedes® Heater Hose, Left (124)

It's always a good idea to do periodic checks of the cooling system hoses, especially if they are a few years old. Inspect upper and lower radiator hoses along with the smaller heater hoses. Look for cracks, swelling, or any signs of deterioration. Cracks may become more noticeable if the hose is squeezed. If replacing radiator hoses, it is wise to replace the upper & lower hoses at the same time even if only one looks bad. Under normal operating conditions, hoses will break down at approximately the same rate.