Time to close system up, without thermostat Get a bottle, or three, of decent radiator flush. That will start another argument as to which one. Flush system . Then remove bottom hose , wrap rags round a hose pipe stuff into bottom of rad and back flush. I now have a De humidifier! That provides me with nice clean soft water for re-filling radiators, rain water is the other old chestnut, but catch in a clean plastic container. I also add K Bar conditioner to the mix and leave it in. With the state of the system new rubber hoses would be a good idea. Quick Note: Some vehicles can be touchy were the thermostat relif hole is positioned, don't know on your one.