Due to a split in the upper radiator hose, I recently replaced all the hoses in the engine compartment, and the thermostat. The hose from the heater core to the engine passes through a firewall grommet. All the engine compartment hoses AND the part of this hose in that area were 'sweating', the reason I replaced them - probably originals.

However, the part of this hose 'between' the firewalls appeared ok, though I replaced it , of course. For this reason though, I did NOT replace the two hoses that connect to the water valve, also in this area, as they appeared ok too. My assumption is that the reduced heat entering this area allows longer hose life - but I don't want to be fooled by external appearance. There is no visible sign of distress on these two small, hard-to-access hoses. Are they likely ok?

Also, I put in Prestone coolant, and am not satisfied that I properly flushed the old coolant (with a lot of remaining brown crud) what is the proper procedure for completely draining the system. My radiator - replaced in the past - appears to have no draincock.

Steve