97OB>How to flush coolant system?

Loading thread data ...

The easiest way is to let someone else do it but, if your a DIYer like me. Get a large pan (> 2 gal) and lots of rags and one gallon of 100%coolant or two gallons of premix 50/50 and 3 gallons of distilled water. Remove the under cover. Unscrew to radiator drain (it's a pain) and as it's draing remove the radiator cap. Siphon out the reservoir. Tighten the radiator drain screw and refill radiator with distilled water. Run the engine with radiator cap off and fill with distilled water as needed. Let engine run until the top hose is HOT. Let engine cool and drain radiator again. This is probable good enough if the drained distilled water looks clear and if not repeat this step. Now there is some water still in the engine and if you want a 50/50 % mix then get a clean gallon container you can pour from and mix 60% coolant and 40 % water and add to the radiator until full. Start engine and run to hot while adding coolant mix as needed. when the top hose is HOT (thermostat open and coolant has circulated turn the engine off and let cool. When cool top up radiator and tighten cap and add to the coolant bottle. Keep an eye on the temp gage for a couple of heating/cooling cycles AND check the coolant level in the overflow bottle. ed

Reply to
Edward Hayes

I'm not sure about the OB, but my WRX has a drain plug on the bottom of the engine block that allows you to drain all the old coolant that normally is trapped behind the thermostat and difficult to remove.

I put some black permatex on the threads as a sealer when I put it back, but any automotive thread sealant should be adequate.

Reply to
2Stroke

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.