'66 SMALL BLOCK COOLANT LEVEL

[Rob A.]

I drained SOME of the coolant out of the radiator to replace the thermostat. I put additional coolant back into the reservoir. Will that coolant make its' way back into the system, or do I need to add the amount I drained in a different way?

[Kevin M.]

Re: '66 SMALL BLOCK COOLANT LEVEL

Only way to add coolant is through the reservoir, when the thermostat opens it should drain out of the reservoir.

Kevin

[Rob A.]

Re: '66 SMALL BLOCK COOLANT LEVEL

Sounds good...thanks...

[Chuck R.]

Re: '66 SMALL BLOCK COOLANT LEVEL

What I sually do is slowly add coolant back through the thermostat opening until it's just about flush with the intake flange. Then I re-install the new thermostat, gasket and neck.

I always worry about that dreaded bubble of air that can get trapped in the block.

I then top off the reservoir and fire it up. Then it's a matter of a small addition of fluid as the hoses and minor cavities will need to be purged as well.

Chuck

[Joe R.]

Re: '66 SMALL BLOCK COOLANT LEVEL

Hi Chuck:

To avoid the "dreaded bubble of air" that you refer to, some people recommend drilling a small hole (about 1/8 inch) in the thermostat flange. This is enough to let air get past a closed thermostat, but not enough to defeat the thermostat function. I think the only side effect is a slight increase in the time it takes for the engine to reach operating temperature.