Starting and running Reductant pump When the reductant pump is new, the check valves may need to be slackened. IMPORTANT! Blow the reductant pump suction nipple with compressed air (approx. 6 bar) for at least 3 sec- onds before starting the engine for the first time. Start the reductant pump immediately after the reductant tank has been filled for the first time. 336 838 Reductant pump OPM 300 en-GB 24 © Scania CV AB 2015, Sweden