Warning: Allow the engine to cool completely before performing this maintenance operation. Also, don't allow antifreeze to come into contact with your skin or the painted surfaces of the motorcycle. Rinse off spills immediately with plenty of water. Antifreeze is highly toxic if ingested. Never leave antifreeze lying around in an open container or in puddles on the floor; children and pets are attracted by its sweet smell and may drink it. Check with local authorities (councils) about disposing of antifreeze. Many communities have collection centres which will see that antifreeze is disposed of safely. Antifreeze is also combustible, so don't store it near open flames.
Draining
1. On XL600V and XRV750 models remove the fairing side panels, on XL650V models remove the fairing, and on all models remove the belly pan (see Chapter 8).
2. Cover the pressure cap with a heavy cloth and remove the cap from the top of the radiator by turning it anti-clockwise until it reaches a stop (see illustration 18.8). If you hear a hissing sound (indicating there is still pressure in the system), wait until it stops. Now press down on the cap and continue turning the cap until it can be removed. Also remove the coolant reservoir cap.
3. Position a suitable container beneath the water pump on the left-hand side of the engine. Unscrew the drain plug and allow the coolant to completely drain from the system (see illustrations). Retain the old sealing washer for use during flushing.
![](https://motoinstruction.ru/img/honda/19/125107.jpg)
28.3a. Unscrew the drain plug...
![](https://motoinstruction.ru/img/honda/19/125108.jpg)
28.3b ...and allow the coolant to drain
![](https://motoinstruction.ru/img/honda/19/125109.jpg)
28.3c. On XL650V models access the drain plug (arrowed) from underneath
4. On XL650V and XRV750 models, place the container below the coolant reservoir (on XRV750 models remove the right-hand side panel to access it - see Chapter 8).
Disconnect the radiator overflow hose from the bottom of the reservoir and allow it to drain into the container. When the reservoir is empty, flush it out with clean water, then reconnect the hose.
5. On XL600V models, to drain and clean the reservoir you will either have to syphon out the coolant, or remove the reservoir and tip it out. Removing the reservoir involves removing the rear shock absorber (see Chapter 6).
Flushing
6. Flush the system with clean tap water by inserting a garden hose in the radiator filler neck. Allow the water to run through the system until it is clear and flows out cleanly. If the radiator is extremely corroded, remove it (see Chapter 3) and have it cleaned by a specialist.
7. Clean the drain hole in the water pump then install the drain plug using the old sealing washer
8. Fill the cooling system with clean water mixed with a flushing compound. Make sure the flushing compound is compatible with aluminium components, and follow the manufacturer's instructions carefully. Fit the pressure cap and the reservoir cap.
9. Start the engine and allow it to reach normal operating temperature. Let it run for about ten minutes.
10. Stop the engine. Let it cool for a while, then cover the pressure cap with a heavy rag and turn it anti-clockwise to the first stop, releasing any pressure that may be present in the system. Once the hissing stops, push down on the cap and remove it completely.
11. Drain the system once again.
12. Fill the system with clean water and repeat the procedure in Steps 6 to 11.
Refilling
13. Fit a new sealing washer onto the drain plug and tighten it securely.
14. Fill the system with the proper coolant mixture (see this Chapter's Specifications).
Note: Pour the coolant in slowly to minimise the amount of air entering the system.
15. When the system is full (all the way up to the base of the radiator filler neck), start the engine and allow it to idle for 2 to 3 minutes. Flick the throttle twistgrip part open 3 or 4 times, so that the engine speed rises to approximately 4000-5000 rpm. then stop the engine. This process will bleed any trapped air bubbles from the system.
16. If necessary, top up the coolant level to the base of the upper radiator filler neck and install the pressure cap. Also top up the coolant reservoir to the UPPER level mark (see Daily (pre-ride) checks).
17. Start the engine and allow it to reach normal operating temperature, then shut it off. Let the engine cool then remove the pressure cap as described in Step 2. Check that the coolant level is still up to the base of the upper radiator filler neck. If it's low, add the specified mixture until it reaches the base of the filler neck. Refit the cap.
18. Check the coolant level in the reservoir and top up if necessary.
19. Check the system for leaks. Install the fairing side panels or fairing as required, and the belly pan (see Chapter 8).
20. Do not dispose of the old coolant by pouring it down the drain. Instead pour it into a heavy plastic container, cap it tightly and take it into an authorised disposal site or service station - see Warning at the beginning of this Section.