Hello all,

I got my AST deleted with longer neck and 1.3 bar radiator cap. When the car is hot it seems to squirt a bit of coolant out. but that stops after probably about 10oz of coolant lost. If I don't fill it up, it's fine but if I do, it will squirt again.

my theory is that may come from the radiator cap. is 1.3 bar enough? what do you think causing the problem?

thx

 

go 'rent' a coolant system / radiator pressure tester and use it to try and find the leak.

 

aren't you supposed to use a .9 bar cap? thats what I use.

 

I believe AST delete require to use higher pressure cap.

 

No...it doesn't. Use the. 9 bar cap.

 

If your overflow tank is full when the system is cold, it will overflow when the engine gets hot as coolant expands.

 

Are you filling it up at the cap for the AST delete/filler neck or are you filling up the overflow tank behind the pass side headlight?

 

The original cap was 1.3 bar.

But Mazda's original water hoses were poor quality and along with the high engine heat, there was leakage and fires. The recalls if you looked them up, included some new hoses and lower pressure cap of .9 bar.

Just as the first engine wiring harness was of poor quality.

With all the improvements that we have done to our cars over the years to reduce heat and improve air cooling flow over the engine, many have gone back to 1.3 bar.
1.3 bar is used on many cars. Helps reduce engine hot spots boiling.

 

I fill up at the cap not the overflow tank.

 

When using a pressure cap with the hose connected to a overflow tank, wouldn´t the pressure cap prevent the cooling fluid to re-enter the cooling system once the engine cools down again, causing the cooling system/engine to be low on coolant when first starting the engine?

 

Interested to hear how this works. I thought about that when I was deleting my AST, but just did it and trusted the advise of the forum over my logic, so am really interested to hear the technical side of how/why it works now that you asked the question

 

A radiator pressure cap has a little valve built in, to allow coolant to flow back into the cooling system when the engine cools.

 

Aha! That's a pretty simple solution/answer
thanks