pull the drivers side wingliner out and you will see the pump. there is no outlet pipe. the pump pushes straight into the bottle. remove the pump and just pour loads of water into the top of the bottle to flush it out but you will most probs find the pump is blocked or has gone down. there not that expensive. we get a lot of c5s in with the tops missing so make sure you have one on after flush so it does not happen again. its common for these pumps to go down even more so after a frost. good luck.