2005 Honda civic lx coupe (manual) radiator is building pressure and trying to escape from cap.

[KaiCivic]

Hello I am looking for help because my i recently replaced my radiator and thermostat due to a crack in my radiator. I have just replaced it and I am building pressure in my radiator and it’s causing it to come out the cap. I have burped my system twice and it still is occurring. What should I do? What should I be looking for?

 

[nd4sped]

Sounds like the readitoar cap needs to be replaced. They have a spring and diaphragm inside, that over time they will degrade.

The radiator cap is what maintains the proper pressure in the cooling system. When the pressure gets too high due to heat, the cap opens and allows coolant to flow into the overflow container. Since the system is sealed when it cools down it will naturally pull the extra cooling water from the overflow tank back into the system as it should.

Start with replacing the radiator cap, its only a few dollars.

If you replace the cap, and you find leaks elsewhere. Fix those leaks and then re-pressurize the system.

 

[KaiCivic]

I have replaced the radiator cap and I am still getting coolant coming out of the cap around the neck,

 

[KaiCivic]

Should I buy an OEM radiator cap
This one is from AutoZone

 

[Brak]

is it coming from the neck near the cap? or out of the overflow tube that's located on the neck (should have a hose attached)?

 

[Brak]

hard to tell from the pic, but it looks like it's spraying all over.
if that's the case, the upper plastic on the radiator may be cracked.

 

[KaiCivic]

It’s coming from around the cap and it’s not making it to the overflow the reservoir that radiator is brand new.

 

[KaiCivic]

It might be coming out of the overflow tube aswell

 

[nd4sped]

See if you can get a clear image or video of the coolant escaping if you can.

Its possible the radiator neck is cracked....

Let it cool and take off the cap, take another photo/video.