So, I finally changed my head gasket yeasterday (I needed to change it because of some overheating problems - read here https://honda-tech.com/zerothread?id=826260).

Installation was easy and without any problems, no leaks etc. The OEM gasket looks more quality than my previous aftermarket one.

I have some questions:

1) When should I top coolant in the radiator - with engine cold or hot? With engine running or stop?

2) Should the cooling system be little pressurized while running or the hoses should be soft the same as with cold engine? If there should be pressure, what causes it? I assume that the cooland doesn't expand with temperature, right? Anyway, the pressure is not so high as with my old faulty head gasket (my hoses were hard like stone, now you can push it).

3) If I don't bleed all the air form the system, will the bubbles go out itself after some time?

Thank you,
Petr

 

1.I always fill the rad up to the top, then run the car with the cap off for a few minutes. Fill as necessary.
2.With the cap on, the system is presurized, but not to the point that the hoses become solid.
3.I would bleed the system. its fairly easy to do. Ther should be a bleeder screw by the thermostat or on the head.