Coolant filler cap inside the level is low whats causing it???
 

guys i just had my new radiator placed inside with the coolant filler cap filled to the top of the neck, well a week has passed and i looked again in the coolant filler cap and the level has gone really low! whats causing it ?? i just had a new radiator put in along with an ast tank!!!! my water temp gauge the shity one that the car has still gives me a normal temp reading in the dab middle between the stupid hot and cold, i would really appreciate is someone can figure this problem out, thanks brothers!!!!!!!!!!!!!

Sounds like you still have air in your coolant system. Every morning before you start your car, you should top off your filler neck. Do it every morning until it's at a good level.

Also, when you add that coolant, pump the radiator hose a few times and bubbles will come up. Repeat this for a while until the level stays. This took me a loooong time.

the coolant sytem on these cars are a bitch to deal with very very touchy. you still have pockets of air in the system!! quick tip take the hose that goes to the tb and bleed it from that!!also check your coolant and oil every time you start it up. just good practice

I read somewhere that if you even have a pinhole leak in any of the hoses to the AST, it will prevent it from sucking fluid back up from the overflow. A possibility since you mentioned having changed it. More than likely it's just air in the system. I'm dealing with the same thing right now.....

FWIW:

Coolant cap and car not keeping coolant / coolant always low

I doubled-checked the new cap, and the overflow valve is not spring-loaded closed.

I went to the McParts store, and all of the new same model number caps (Stant #331) are designed this way.

I did find a Stant 16-lb. cap (pn# 11230) that had the overflow valve spring-loaded closed, and all is well again.

The only way to check is to inspect the cap from the side to see if the valve hangs down, and to gently pull on the valve to see if it is spring-loaded closed.

I'm wondering if this should be a "stickie" . . .

Check out the pics:

https://www.rx7club.com/showpost.php?...0=&postcount=10

PS: I also found a 13-lb. cap with the spring-loaded overflow valve.

:-) neil