Motorcycle coolant should be changed at least every two years, or 24,000 miles because its performance deteriorates over time. (Check your owner’s manual for your motorcycle’s specific coolant replacement interval). Aluminium corrosion or changes in the fluid-to-coolant ratio are the usual causes for this.
The coolant change solution should be kept as alkaline as possible, which is why most motorcycle coolants include specific ingredients to help achieve this. However, these become less effective over time.
What type of engine coolant do I need for my motorcycle?
Ensure you choose an engine coolant made for aluminium alloys, since all motorcycle engines are made of these.
How much motorcycle coolant does my bike need?
Most bikes have a coolant capacity of three to four litres, although this can vary.
Coolant for motorcycles: What types of motorcycle coolant are available?
Most motorcycle coolants are pre-mixed and ready to add, but some coolants are sold as pure antifreeze; pure antifreeze motorcycle coolant must be diluted with distilled water – usually at a ratio of 50:50.
There are two kinds of motorcycle coolant; propylene glycol and ethylene glycol. The two types of coolant should never be mixed.
What you need to change your motorcycle coolant
When undertaking a motorbike coolant change, you'll need a funnel and enough premixed coolant, or pure coolant and distilled water. Never use tap water or water that has not been distilled.
You'll also need appropriate screwdrivers and Allen keys in order to remove the panels and fairings – enabling access to the main drain bolt.
A tray for collecting the old coolant and some rags for any spillages are also necessary.
Risks of changing your motorcycle coolant
If you attempt to open the main drain bolt after the engine has been running, you run the risk of being scalded. This is because the system has become pressurised, causing the coolant to erupt.
Can you use car antifreeze in a motorcycle?
Wondering, can I use car antifreeze coolant in my motorcycle?
For long lasting cooling performance, you should only use the recommended coolant/antifreeze for your motorcycle as motorcycles need special antifreeze coolant.
Using regular car coolants for your motorcycle could end up causing costly damages to your bike.
You should ensure that you do not mix different types of coolant.
If you are tempted to use a car coolant for your motorcycle reservoir, make sure the spec is the same: Make sure that the car coolant does not have silicates, and that it contains Ethylene Glycol antifreeze.
Leave the job to a professional if…
You don’t have a spare hour to complete the task, or if you have a history of putting window cleaner in your coolant tank!
How to change your motorcycle coolant:
- Place your bike upright on a paddock stand. On a sports bike you may need to take off most of the fairing in order to access the radiator cap, header tank cap and drain bolt. Some drain bolts are located on the same side as the side-stand; if yours is, place the bike on the side stand in order to facilitate the draining process.
- The majority of drain bolts are found on the lowest part of the motorcycle cooling system, or on the housing of the coolant pump. For bikes without drain bolts, the lowest hose should be removed in order to drain. Be sure the coolant is cold before attempting this task.
- Put some kind of tray or other receptacles under the drain bolt, then take off the radiator cap in order to relieve any system pressure and permit the coolant to exit with ease. Turn the drain bolt a few times to loosen it and make sure any sealing washer is loose too. Take off the bolt and washer.
- After draining, clean the exit hole, the bolt and washer. Refit the bolt and washer. Replace the washer if it is damaged in any way. Ensure the bolt is closed tightly.
- Prepare the coolant and the funnel. Be sure you have used distilled water if you are diluting your motorcycle anti-freeze. You can use boiled tap water as an alternative – but as mentioned, do not use regular cold tap water, as it contains clogging and corroding minerals.
- Insert the funnel in the radiator top and steadily fill with motorbike coolant. Pause regularly to enable any trapped air to escape. Purge any trapped air in the hoses by squeezing them gently. Fill coolant up to the point where the boom of the rad cap will be when fitted.
- After refitting the radiator cap, pour coolant into the header tank, filling it to the point halfway between the upper and lower fill marks. If there are bleed bolts present, use them to release any air, being sure to re-fix them tightly.
- Turn the engine over for a minute and check to make sure there are no leaks. Idling the engine in this way should release any remaining trapped air.
- Take off the radiator cap and check that the motorcycle's coolant level is satisfactory. Top up with additional coolant as required. Check the header tank level too and if empty, repeat stage 8.
- Idle the engine again – long enough for the cooling fan to engage – then turn off. Wait for the engine to cool, then check the header tank level once again, topping up with further coolant as required.
- Clean any coolant from the motorbike bodywork, as it can corrode plated metal parts. Use soapy water to wash down. Store any remaining coolant securely away from children and animals.
Can you use car coolant in your motorcycle?
As explained above, as long as the bike coolant contains ethylene glycol antifreeze and does not have silicates, it can be used in either car or motorcycle.
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