Coolant System Under Pressure

[wildeagle44]

Hi all.

Took the car out for the first time, rb25 s13. The coolant system seems to be pressurising? When it's upto temp the radiator hoses get pretty hard and it actually burst a hose from the radiator to header tank (cheap thin ebay hose may have been the issue). It didn't get past 92deg so not like it overheated.

Radiator cap on header seems alright, radiator has a blanking cap on it and thermostat was tested working before i put it in.

Bled up all good, no bubbles or residue in the tank.

I'm fearfull of a headgasket but it was fine beforehand. Any other ideas? Or is it normal?

Thanks for any help.

[Ben C34]

Have you ever owned a car before?

They all pressurise the cooling system.

[Hadouken]

I don't know, he says it was fine before

[wildeagle44]

Sorry i realise that it's under some pressure.

Just that the header tank hose bursting was an alarm bell to me.

[Scott Black]

how thick are the lines going to the header tank, as in diameter, whats the radiator cap rated at?

[Ben C34]

The cap is what determines what pressure the system can reach.

Are you using the same cap as before?

[wildeagle44]

1/4 inch lines but they were pretty thin wall and not proper heater hose.

It's a 1 bar cap.

It's a different cap that before. I'm using the fenix cap that came with the radiator.

Last one was just an ASI.

[KiwiRS4T]

1 bar cap should be fine. But check that the size and depth etc is same as stock.

Otherwise go with your original diagnosis of rubbish cheap hose and put something better on.