Hi Rob, your Ryobi washer looks very similar to mine, which is called RPW2400. You can download the operator's manual here:
http://www.ryobi.com.au/Ryobi/files/ca/ca71eacc-4157-4e7a-bbea-10675f3bc1c9.pdfThe literature describes the pump as "maintenance free". Essentially, the instructions are first, never run the machine without a pressurised source of clean water attached to the pump intake, and secondly, drain the water out of the pump before storage, by pulling the starter cord half a dozen times with the input and output hoses disconnected and the ignition off. For long term storage Ryobi mentions but does not specifically recommend, the use of "Pump Saver". This a Briggs product in a pressure pack. After preparing the machine for storage, including pulling the starter to drain the pump, you put the pressure pack on the pump intake (water hose fitting) and press the spray button until the goo comes out of the pump outlet (pressure hose fitting). The idea is to protect the seals etc., primarily in the northern US winter when it gets very cold. I don't use the stuff, for various reasons, none of them necessarily convincing ones. My storage process is disconnect and drain the hoses and wand, drain the fuel via the float bowl drain fitting, then pull the starter so it runs for about 2 seconds before dying, which causes a surprisingly small amount of water to come out of the output hose fitting. So far I've never stored it for long enough to put oil in the cylinder.
