The OM-4 attachment is designed for roadway washing. The superstructure consists of grading combs with vertical and horizontal nozzles. The mechanism is also equipped with two side nozzles and a valve to which a hose with a remote washing gun is attached. Water pump on hydraulics provides liquid supply from reservoirs under pressure up to 25 atmospheres. Water can be supplied to one or several components of the equipment at once. This allows to reduce fluid consumption by 4-5 times compared to the operation of a classical installation and to improve the quality of the equipment in operation by an order of magnitude.