Today at Atelier Kaz - ex-Honda R&D, F1, Indy/CART engineer

Now ready to take the car out for the 1st test driving session.

For the test driving session, even in the hot summer,
I’m afraid you want to keep the A/C CCU temperature setting at higher temperature range to keep the water valve open.


I always set the CCU temperature dial at max but keep the fan speed to min for at least 5min during
the test driving session even during the hot summer.

Park the car overnight.

Now time to revisit the heater core bleeder.

This is especially important for those with the rubber cap bleeder.

While the engine is cold, remove the tank cap.

Now crack open the heater core bleeder or lift the rubber cap just enough to let the air/coolant escape from the L-shaped pipe.

If no air or just tiny amount of aerated coolant, good news and no problem.

If you hear just hissing sound with no coolant for like 1sec followed by the coolant,
you may need re-visiting here again for the next few outings.


Adjust coolant level, close the cap and done.


Unless you track regularly with the aged radiator,
you should not need topping up the tank until the next coolant service.


I never touch the coolant for the next 4 years using the OEM Type-2 coolant.

It can go for 5 years but I prefer slightly shorter service interval.


There is no need adding any chemicals or the use of different type of coolant.

If cooling efficiency is the highest priority, just use plain water.

No rust inhibitor or WP protection though….


If you think the coolant never boils even under perfect condition,
imagine how high the temperature gets at the surface of the cyl water jacket and
what happens with the coolant at the surface while pushed by the force of the WP.


Never recommend doing this but think about what will happen if you quickly put your hand in and out of the liquid nitrogen.

That’s one side of the cooling system.


Kaz