coolant change, just afew Q's (Nc30)

[Benc30]

Have hunted high and low for my haynes but cant find it since i moved house..

where abouts is the coolant drain plug...?

do i have to use distilled water?

and whats the best method for bleeding the system up, or does it self bleed?

also how much water does it hold, IIRK it takes 2litres in total of water coolant mix...????


cheers folks

[CRM]

if i recall the drain plug is a 8mm head bolt on the water pump on the lower left of the engine.
ideally use distilled, or procool or similar. however collect some rain water, boil it then use that at a push.
bleeding, add slowly to the rad, and work the hoses squuezing out any bubbles and get it moving. crank it over half way through filling to move the pump and get some movement.
refit cap, run till hot, leave to cool, then top up as required.

[Neosophist]

I think it's a 10mm bolt on the water pump.

You'll also see two drain screws under the front down pipes that let water out the block.

You must use distilled water, normal water has too much crap and scale in it and will build up deposits in your cooling system.

50/50 water / antifreeze.

The service manual says run the bike with the cap off when full (on the sidestand) until the thermostat opens (you'll see the water level drop / move, temp about 1/2 way.

Snap the throttle to 5000rpm and let it settle, do this a few times to purge air trapped in the system.

Doesn't hurt to give the lower hoses a quick squeeze too.

Let it cool and top up and fit cap

[Polisher]

CRM is right, its a Honda type 8mm socket size with a 6mm thread on the pump and there are 2 drain bolts
on the front 2 cylinders under the exhaust down pipes which are a pig to get to!

I used a rad flush first and got it nice and warm to help dislodge the gunge as mine had been stood for 7 years.

When its all drained out run a hose pipe through the rad filler cap to flush any gunge out, i left it running for about 20 mins.
Refill slowly with appropriate coolant, dont skimp on this, and squeeze the rubber rad pipes from time to time to expell the air.

Dont forget to put the bolt back in the waterpump like I did and lost 3/4 litre of coolant - thought it was taking a long time to fill ...... Doh!

Neil

[Neosophist]

Haha.. You didn't notice the flood under the bike? :)

Which rad flush did you use? I had one that had been run on tapwater for long enoguh to destroy the water pump... I tried Bars 2 part rad flush.. ones an alkali chemical that disolves the corrosion, the other bottle is a neutraliser.. got the system looking shiney and i'd recommend it again over the single 'sand in a bottle' types.

[Benc30]

cheers folks bikes very low milage so cooling system is mint and i wanna keep it that way...

are the drain screws location obviouse?

[Neosophist]

[Benc30]

ah ha thats great thanks for that!

[Polisher]

I used the bars flushing system too, didnt notice I'd left the waterpump bolt out as I was too busy pissing my boss off on the phone at the time, and left the hose running............................