Cooling System Flush/Coolant Replacement, Gen1
Do not do this procedure when the engine is hot. The hoses seem to come off easier if the engine is slightly warm, however.
It is best to do this procedure with the bike on its side stand. Raising the bike on a rear stand will increase splattering of coolant while draining. Many of the pics included show my bike on a rear stand but this is unnecessary. A pan may be placed next to the side stand to catch all fluid drained from the water pump. Have a bucket of water and a cloth ready to immediately wash any spills or spatters on the bike.
Do not run the engine without liquid in the cooling system. The water pump can be damaged if run without fluid in it.
The procedure of emptying and filling the cooling system is simple, however after the system is flushed, there may be 8 to10 fluid oz of almost pure distilled water left in the engine. The left over flush water is enough to lean out the fresh coolant that will be added so that it will not have the maximum antifreeze protection. The easy solution to this problem is to just drain the system and then fill it up with fresh coolant without bothering to flush with distilled water. You can also flush with distilled water followed by flushing with a batch of properly mixed coolant. The residual flush water in the system will disperse into the flush coolant. Empty and the flush coolant and add pure coolant until it tests the proper strength with a coolant tester and then pour it back in. Either that or discard the flush coolant and refill the system again with fresh properly mixed coolant.
Because achieving a 50/50 proportion of coolant/distilled water is problematic after flushing with distilled water, I do not suggest using premixed coolant. The adjustments to offset the residual flush water are very small in volume so it is impractical to attempt them with anything but 100% coolant.
Do First:
Turn engine kill switch to off to prevent accidental starting of motor with a dry water pump after draining the system.
Remove ram air tube covers, formans, tank cover fairing, lower fairings and side fairings (Fairing Removal).
Leave the inlet hose connected to the coolant reservoir and remove the reservoir. (Engine Coolant Reservoir Removal, step 1)
Tie the reservoir to the bike so that it does not hang on the hoses.
Tools:
8 mm wrench
drain pan
large empty container
distilled water
handle of a screw driver
Optional: new water pump drain plug gasket
coolant antifreeze tester
Draining
1. Remove radiator filler cap on the right, top side of the radiator. The cap comes off by turning counterclockwise one half turn to the stop and then pressing down to turn one half turn off.
2. The water pump is on the clutch lever side of the bike near the bottom of the engine and it has a large hose encased in a spring coil connected to it.
Remove drain plug and metal gasket from water pump using an 8 mm wrench. The plug has been removed in the photo below.
Be prepared to catch a stream of coolant which may project out of the drain hole about 10 inches. It also may only drip because of surface tension in the liquid but be ready holding the drain pan in case it shoots out.
3. When the stream slows, place the drain pan under the bike to catch the remaining coolant.
Install the drain plug into the water pump gently using an 8 mm wrench when the coolant stops running. Avoid unnecessary wear on the gasket and threads.
The radiator is constructed of a tube that runs back and forth several times through the fins in parallel fashion from the filler neck to the radiator exit. The tube turns sharply at the end of each course. Coolant can remain trapped in the tube as well as other parts of the cooling system.
Lean the bike slowly to the left and then to the right as far as possible several times to allow all coolant to run down to the water pump.
Remove the drain plug one more time and drain the final amount of coolant.
Put the drain plug in again snug.
4. Empty the coolant from the reservoir into a large empty container. Also empty the drain pan into the container.
5. Remove one end of each water hose (see Water Pipe Removal —Gen1) and drain the fluid that comes out into the container for disposal.
It is best to empty all hoses if possible but you should drain at least the largest ones.
The hose that is encased in the long steel spring will probably have tiny chunks of gravel around the top edge where it connects to the radiator. It would be best to remove the end of the hose that connects to the water pump if you choose to drain it.
You may notice some chips of paint flaking off of the tips of the water pipe nipples. You might as well try to remove as much loose paint as possible before it ends up in the cooling system.
Fill/Flush
6. Reconnect all hoses. It is not necessary to clamp any of them as they will soon be getting disconnected again.
It is not necessary to reinstall the coolant reservoir.
Slowly pour distilled water into the radiator until it reaches the top of the filler neck. It is important to pour slowly to help avoid trapping air in the radiator.
Although the distilled water is only for cleaning out the system, this is also a good opportunity to practice properly filling and bleeding air from the system when it gets filled with fresh coolant.
Do NOT use ordinary tap water even just to flush. Distilled water is inexpensive and it is safe for your system (actually, the Service Manual doesn’t recommend that even distilled water be left in system for long periods of time without being mixed in the proper proportions with coolant).
Burp
7. Install the radiator cap and tilt the bike left to right as described in step 3. Listen for gurgles of moving air pockets.
Remove the radiator cap.
Turn the engine shut off switch to ON, place the key in the ignition and start the engine.
Pour additional distilled water into the filler neck as the engine water jackets are filled by the water pump.
Be prepared to catch the water that drips out of the filler neck as the water expands through warming.
Use the handle of a screw driver to tap all hoses to release air bubbles stuck to the inner walls.
Burp the larger hoses by squeezing and releasing them rhythmically like a heartbeat. This action will surge coolant through the system which will encourage air pockets to dislodge and move downstream.
Watch the radiator filler cap as air bubbles rise to the top of the water (see picture, step 14 of this tutorial). When the air bubbles stop, the system is bled of air.
Shut OFF the ignition and engine kill switch.
Use a wet cloth to rinse off the side of the radiator where coolant trickled and all other painted areas where coolant may have spattered.
Drain
8. Allow the engine to cool.
Remove the drain plug from the water pump and catch the distilled water in a pan as in step 2 and 3 of this tutorial.
Remove each hose and empty the water into a pan as in step 5 of this tutorial.
Rinse the inside of the coolant reservoir with distilled water and pour it into a receptacle.
Pour the flush water into a receptacle for disposal.
9. Repeat steps 9 through 12 of this tutorial at least one more time. I flushed drained 3 times before the distilled water came out looking almost clear.
Fill/Test
10. According to the Service Manual, the capacity of the cooling system is 3.4 liters (3.6 quarts) but there is a small amount of pure water left in the system after flushing. The amount of leftover water is important to consider as explained in the beginning of this tutorial.
Mix a new batch of coolant according to manufacturer’s directions. Test the fresh coolant with an antifreeze tester and note the result.
Reconnect the hoses and hose clamps (see Water Pipe Removal, Installation).
Reinstall the water pump drain plug and gasket. The service manual recommends a new gasket. In my opinion, it can be reused a few times if the plug is not over-torqued.
Torque - Coolant Drain Bolt: 10 N·m (1.0 kgf·m, 89 in·lb)
Reinstall the coolant reservoir (see Engine Coolant Reservoir, step 3)
11. Slowly pour new engine coolant up to filler neck as described for flush water in step 6.
Do not fill coolant reservoir.
Turn ignition and engine kill switch ON and start the engine.
Burp the hoses as described in step 10.
Run the engine for several minutes to circulate the coolant and mix it with residual flush water in the system while catching the overspill in a pan below the radiator. Save the coolant that spills over so that it may be added later.
12. Turn off the engine and install the radiator filler cap.
Rinse off the side of the radiator and all other painted surfaces that may have come in contact with drips or spatters of engine coolant.
Allow the engine to sit for several hours or over night to cool completely.
13. Remove the radiator filler cap. The coolant level will be low after the coolant contracted from cooling.
Use an antifreeze tester to check the strength of the coolant. It is important to test coolant after it has cooled completely. If it is warm at all, it may test stronger than when it is cool. The coolant will likely be weaker than when initially tested in step 13 because it has mixed with the residual flush water in the system.
14. Add the extra amount of pure coolant or distilled water to the radiator that you estimate is needed to restore the coolant to the proper strength.
Start engine and run for a minute to verify that the system is bled of air. Be prepared to catch any coolant that runs over.
Shut the bike off and pour the overspill back in the radiator until it is full to the neck when resting on the side stand.
Add 50/50 coolant/distilled water to coolant reservoir so that it is filled to between the Full and Low marks on the reservoir.
Install the filler cap and ride the bike to mix the contents of the system thoroughly.
Allow the coolant to cool completely and test again to verify that it is mixed to proper proportions.
Test the coolant when cold. If the proportions still require adjustment, repeat step 17 removing a small amount of coolant first if necessary until the coolant tests to the proper strength.
If the coolant tests to the proper strength, fill the radiator with 50/50 coolant/distilled water to the top of the filler neck with the bike resting on the side stand.
Operate the bike for 50~75 miles to thoroughly mix all the fluid in the system and then test the coolant strength when the bike is cold. Repeat step 17 until the proper strength of coolant is achieved.
* Last updated by: Rook on 12/10/2017 @ 4:41 PM *