I’m changing the coolant, now it might just be me but few people seem to pay any attention to this? there may be good reason? I’m about to find out anyway….The bike must be cold to do this so that there is no pressure when you take the radiator cap off, or scald yourself on hot coolant (does that make sense ?) as it drains.

There are three points to drain the system, first up you have to loosen the radiator cap which will require the removal of the plastic radiator cover from the near side. have a a bucket ready, the coolant will spurt out to start with ! so be prepared. If you have a cat or a dog keep them away from the coolant as it is VERY TOXIC for them.. and for some strange reason they seem to be attracted to it !!

Have a container with a screw top available to store the spent coolant in, it will need to take about 3 ltrs, a funnel is also handy at this stage. First drain plug is the engine block…..

Then the drain plug on the water pump

Then the lowest part of the system, this is the intake from the radiator to the water pump but it has a lower bleed outlet as you can see (the small L shaped tube coming out of the main pipe) I have removed mine completely as it was beginning to show signs of wear and tear it is going to be tarted up one way or another.

Once drained you can remove the expansion tank and empty and clean it, the top tube is just a push fit.

When on the bike mine always looked like it had nice clean fluid in it but the amount of crud lurking in the bottom was like washing Ox tail soup out for the next ten mins ! The kitchen sink was used for this task…always a popular choice…NOT, but it ,allowed fresh water to be flushed through the tank until clean.

As it is all apart I am going to replace the clutch hose as the banjos are beginning to corrode :-(…in for a penny ! it’s always this way, salt is still on the roads and I take on a project with the bike as a sort of rolling restoration on the old bus. as this is an area I don’t intend to work on for the next couple of years I might as well do a proper job, so everything is being sorted..all nuts and bolts, jubilee clips and washers etc are being swapped for stainless and what isn’t being painted is off to be powder coated..

I have removed the water pump for inspection while I’m at it..and I’m pleased to say after I had persuaded it to part everything was in good order, no crud in it and no play on the impeller itself. I’ve rubbed down the pump cover for a lick of paint and cleaned up the pump housing, two new O rings will be required to put it back together one for the pump into the bike and another for the pump cover. New copper washers have been sourced for the drain bolts.


Today I painted the water pump cover and put most of the system back together, just the water pump inlet pipe to connect up when it gets back from the powder coaters, then I can fill the system and finish the job

Parts came back and stuff was put back together…I had to file the excess powder coat off the end of the inlet pipe to the water pump to help make it fit. The rest was easy, just tightening up hose clips etc. Filling the system is straight forward too, fill it at the radiator cap until it is full to the brim, fill it slowly tho, to minimize air being trapped. Then fill the reservoir under the seat to max, as marked on the side.

Fit the cap, start the bike and let it run for 5-6mins, then rev it to 4-5K a few times, switch bike off and let it cool down. Check the radiator and reservoir tank level again, top up if necessary and job done.

I only had one minor worry when coolant started to leak out of the waterpump outlet hose, this was due to me not tightening it enough…anyroad this used to be the ugly side of the bike and thanks to a bit of graft tied into some maintenance it now looks fab.

Tools & parts handy for the job:
Metric socket set
Metric Allen Key set
Flat bladed screw driver
Torque wrench 9NM +
Copper grease
Container (screw top) 3ltr+
Rags/kitchen roll
3ltr of bike coolant
If removing the water pump etc relevant O rings etc to replace for rebuild.