Coolant

[t121anf]

Like most things these days there is too much choice and too much information.

I’d like to change my coolant in my bike, gsxr750 k5 if it matters.

The workshop manual only says it just contain ethylene glycol, can anyone recommend any such coolant?

There are now multiple colours, OAT, non-OAT, waterless (not interested), pre mixed etc, just too much to choose from.

[MCN]

Simple.
Buy a premixed glycol based coolant. Ensure it has minimum 2% inhibitor in it. Some have many haven't. Rule of thumb, if it has it will say on the container if not it won't say.

Drain the old coolant into a container for disposal at your local recycling place/landfill.

Fill with clean tap water and drain again to remove all the old coolant and any detritus. Tap is fine for a cooling system. (Not good for batteries.)
You might feel like adding a flushing chemical and running the engine with that. Up to you.

Make sure the system is drained.
There may be areas that can collect a bit of dead cool a t. Bends of hoses. You should try to get as.much old coolantnout as practical.

Then make sure all the plugs are back in, hoses connected and any drain cocks closed.

Fill the radiator slowly with the new premix.
If you fill slowly it helps prevent air bubbles forming and collecting in the 'high points' of the engine.
Air doesn't transmit heat energy as well as liquid so it creates Hot Spots. Hot Spots can lead to thermal damage to the metal of the head or block. Cracking. £££.

Fill until the radiator is full. Squish the hoses to push any air bubbles out. Top up if the level drops.
Fit the radiator pressure cap.
Fill the expansion tank to the Max Level.
Make sure you set the level cold.

Run the engine up to temp. If there's a fan it should come on as the thermostat opens and cool the coolant.
You should switch off and allow it to cool down a bit until you can put your hand on the metal without getting toasted.
Check the expansion tank level.

Job Jobbied.

I was interested in trying this waterless coolant.

https://en.m.wikipedia.org/wiki/Waterless_coolant

No water so won't evaporate at normal temps.

https://www.eurocarparts.com/p/evans-power-cool-180-waterless-coolant-2ltr-993778002

You don't have to buy from Eurocarparts of course.
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Disclaimer: The comments above may be predicted text and not necessarily the opinion of MCN.

[xX-Alex-Xx]

One extra thing : there's often a bleed valve on the lower half at the back of the engine that needs opening until coolant drips out after you put the new coolant in too. Do this with the engine running.

It's often not really required but it'll be in the service manual if applicable.
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DILLIGAF

[Robby]

I tend to replace it with the same colour it currently has. I don't know if there are compatibility problems between different kinds, and the internet will argue strongly that both options are correct, so I just stick with the same thing.

If you do fill with water for an interim flush, make sure you find all the drain/bleed points to get all the water out afterwards.

Personally, assuming the system was working and this is just routine maintenance, I drain it through the drain hole and refill with the same colour. No other steps, or it turns a simple job where little can go wrong into the other kind of job.

[Easy-X]

[MCN]

[Easy-X]

Suit yourself but the heat capacity of water is 4.2 kJ/kg versus Propylene Glycol @ 2.5 and Ethylene Glycol @ 2.4.
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter