Coolant reads 1/4 inch low after system flush. Whats up?

[Kn38ms]

Had Ford flush the Cooling sytem 2 months ago.
I just noticed the tank is 1/4 below fill line.
I added distilled water to bring to full line.
Drove for hours yesterday and noticed its down a quarter inch again.
There is no coolant smell, leaks or stains that I can see.
Gauge is dead center.
Is the system still burping itself?

 

[006]

Chances are that they did not fill the coolant from the crossover tube.

It's amazing how so many people/places have no idea how to flush/fill coolant on our cars, and this is why I very seriously advocate doing it yourself.

No need to risk a blown motor because someone was too lazy to spend an hour to do it themselves since we have TONS of write-ups on how to do this, and it's very simple and foolproof.

 

[Kn38ms]

Should I open the fill tube and top off with engine running?

 

[006]

Should I open the fill tube and top off with engine running?

Very bad idea

I'd wait till the motor is totally cool before attempting to open the fill cap on the crossover tube.

Do this:
While the motor is still warm, unscrew the cap *slightly* so that it will be easier to fully open when the motor is cold. Be careful not to get hot boiling coolant all over you.

When it's cooled after a few hours, open the cap, remove it and THEN fire up your motor.

Begin to add coolant (yellow bottle - prestone since it's safe for aluminum motors), and do this with a 50/50 mix (don't buy the pre-mixed shit.. that is a waste of money), also pour some into the degass bottle to it's full line.

As the motor gets warmer, you will begin to see bubbles come up through the fill hole on the crossover, and the level will drop, keep filling it until it stops dropping, and then cap it off and tighten it.

Tadaa! Done!