Flushing Cooling System

[CEKing]

I am going to do a flush of the cooling system on my 1996. I am probably going to use the method noted in the Corvette Forum, C4 Tech Tip by Tom Strickland "Coolant flushing tool". I also plan on removing and cleaning the front of my radiator at that time.

I am wondering about the drain adapter that is used in the upper radiator surge tank. I want to be able to keep from getting any coolant on the body and engine or at least minimize the amount of coolant that spills onto the engine and body.

I am also wondering about needing to open the brass bleeder screw on the upper line out of the water pump. Is it necessary to open this bleeder screw when you are draining or filling the cooling system? The location of the bleeder screw would seem to make it very difficult to keep liquid from spilling out on the engine.

I have emailed Tom Strickland for his input to these questions

 

[jmccloud]

Brass bleeder on thermostat housing

The brass bleeder on the thermostat housing is useful for letting the air escape when refilling. Stuff a towel or something absorbent (and much more substantial than a paper towel) under the thermostat housing to absorb any liquid. Make sure the towel is out of the running gear (belts, etc.) before running the engine. The opti-spark is below the water pump and thermostat housing and it's death to let liquid run onto the opti-spark. Expensive too.

Even after bleeding as much air as possible, the engine won't purge all the air until the temperature is cycled 3 time between 200 or so and 'room' temperature. Accordingly, the service manual advised against 'agressive driving maneuvers' until the three cycles (took me 3 days) are complete and the warmed up operating temp stabilizes between 195 and 227 or so. The manual also cautions against letting the temperature reach 260 even with the antifreeze in and pressure cap on. The solution for too high (>260) is to shut it off and let it cool, bleed some air, run again, etc. The whole time keeping some liquid in the overflow tank that is in front of the passenger side front wheel.

Hope this helps