Does anyone know the OEM PSI for the radiator caps. When I purchased my FD it came with mis-match caps that I believe to be aftermarket. Can anyone shed some light on the subject?

Thanks

John F
Nashville TN

 

Hi John,


The cap on the coolant fill, is not a pressure cap, if there is one there remove it.

The cap on the ast is a pressure cap, it should be 13 psi, I believe a few months after the FD was sold in the US there was recall on the pressure caps lowering the pressure from 16 to 13 psi.


You may want to call up Malloy mazda and order new OEM caps.


If you want post a pic of the caps that are on the car and we can better figure out what/if you need anything.


Welcome to the club.


John

 

i recently had a problem with some coolant leaking out of my overflow tank. what was weird is it also did it when the car hadn't even been started, which kinda led me to believe something was up with the pressure. after reading a ton of threads a lot of things were said about what it could possibly be either a thermostat or radiator cap was bad or a small pinhole in one of the lines or we all know the worst a blown water seal. really hope its not the water seal but it would be a good excuse to finally rebuild my motor. point of my post is to ask if the 13lbs. cap is also what its supposed to be on the fc. (tstat filler neck not the radiator)? i think it is just wanted to check

 

Thanks for the advice John. I will try to upload some photos here tonight. What brought this on is that I have had an issue with my "Add Coolant" light has come on. I have done the champagne test and we are all good (no bubbles). It's been a while but I think last time I took it in to Mazda for service they did a compression check and everything was good but they think the cap was the wrong psi or something. I put the car up for the winter after that but forgot to check in to the cap issue. I will post pictures and see what you guys think.

Thanks
John F.
Nashville

 

It seems that I have both a 16 and 13 psi cap. See photos attached.

 

The 16lbs cap should just be a filler cap (ie no pressure.) That should be fixed. 13lb is fine as long as the cap is in good working condition.


How low was the coolant level?
Have you checked the coolant overflow hose for leaks?

Perhaps the system is not sucking the coolant back into the system after it cools down.

 

Thanks man. Coolant level was not very low. Problem was that the system was not sucking up the coolant from the overflow (likely a pinhole leak or problem with my cap). Before I knew better I would just add coolant to the filler. This would result in my overflow overflowing. I thought I had a leak, did checks and found that the leak was coming from my overflow. Now I know better. I still need to find why the pressure is not right and the system is not sucking coolant back from the overflow. Hopefully it is just the stupid 13psi filler cap.

Thanks
John F.

 

This is right