By: Ron Major
Here is the procedure I use to change my coolant
I remove the lower fairing, both maintenance covers, top shelter, left and right fairing pockets, middle fairing inner cover, and left and right middle fairings to do this maintenance. It could be done with less plastic removal, but I also use this opportunity to check ALL of the fasteners on my ST. I then remove the radiator cap and remove the radiator drain plug, and drain the coolant into a suitable container (this stuff is poisonous so dispose of it properly please :-). Next, I disconnect the bottom radiator hose at the radiator and drain the engine block. I then disconnect the two coolant hoses that go to the oil cooler (under the oil filter) ***NOTE: later model STs don't have an oil cooler (shame...). A good way I have found to get that last little bit of coolant out of the block is to put a short piece of garden hose over the radiator cap opening and blow into the other end. This gets every last remenant out of the system without removing the small block drains that Honda so "inconvieniently" placed behind the exhaust manifolds. Finally, disconnect the overflow line at the reserve tank and drain both. I then remove the tank and clean it thoroughly inside and out. A real good method for cleaning inside is to put some small (ice machine size) ice cubes inside the tank and shaking for a few minutes. If your really anal, at this point you can use a garden hose to flush all of the open lines and radiator(messy job). This is a good time to look around for signs of coolant leaks. Look for dry white powdery deposits, especially around the thermostat housing where the hoses hook up. tighten clamps or replace hoses and clamps as necessary. Now connect everything back up (don't forget the radiator drain plug:-), and fill at the radiator cap opening with a 50/50 mix of Prestone 5yr/150K Silicate free coolant and distilled water. Run the engine (in a well ventilated area) with the cap off for a few minutes and add the 50/50 mix as the level goes down. **CAUTION: keep head/face away from the open radiator fill as HOT coolant may "burp" out during this phase and scald you. The level will stop going down after the thermostat opens. Do a final top off of the radiator and replace the cap. Add 50/50 mix to the overflow tank to the "upper level" mark. Turn off the engine and let it cool down. Note any leaky fittings and tighten as necessary. After engine is COMPLETELY COOL, carefully remove the radiator cap and top up with 50/50 mix if necessary. Check the overflow tank and adjust the level as necessary. After you check all of the fasteners on the bike, replace the fairing pieces being careful not to force anything. Go Ride.