Coolant flush

[Granite CB7]

Yeah, they put thread locker on the block drain plug! I could not get mine off when I changed my radiatior. It is a 19mm socket. It's above and to the left of the oil filter housing, and it sits above a coolant (or was it oil ) gallery (long ridge in block for coolant or oil passage) and so it's hidden.

So, I couldn't get that off, I removed t-stat and flushed the system 8x w/ tap water and the last 2x w/ distilled. W/ the t-stat out, you have instant flow when the motor is turned on, so you can flush several times in only 15 min or so.

Good luck getting that off, hope it works out for you!

[SoapyToast]

Also make sure to drain the system with the heater on, so you get ALL the coolant flushed out.

[5speedEX93]

If you don't want to bother with the coolant drain plug on the block, you can flush the old fashioned way.

Drain coolant and add 100% water to the radiator. Start engine and let idle for 5-10 minutes. Drain again and repeat procedure 4-7 times.

When adding coolant the final time add 60% coolant/water to get a roughly 50% overall coolant mixture.


This is how old repair books instruct you to do coolant flushes, and a mechanic friend of mine said that's how they did it for many years. Takes more time, but is very easy to do.

[squig808]

Again, if your anal, just get the honda blue.. 0 borates, 0 silicates.

Blue is such a stupid color for Coolant.

Running the cleaner in there seemed to make a difference. It will dissolve some of the crud. It was like diluted milk pouring out. I'd say it's worth the $5 + time.