Hi racerone, well I took the bottom out today and took water pump off the impeller was worn, tight and blades weren't evenly round the inside of pump. I had to order another impeller and get it Wednesday and will try and put it back in. But when I removed the top of water pump there were no rubber washes either top or bottom of the impeller so assume doesn't have them, I put the hose on the tube that connects to pump and switched the water on and water flowed straight through so there doesn't seem any blockages there, I also replaced the top and bottom gaskets so fingers crossed it is the impeller.