Gilaguy23
TJ Enthusiast
OK
So if its not leaking-- would you say its good?
No. As jerry indicates a bad cap or bad seals which is more the case, wont hold pressure and allow far to much coolant into the overflow bottle as things heat up. It also will disallow the coolant to return to the overflow bottle once cooled down. The work like check valves basically. The cooling system is intended to be a "closed system" free of any air. Inspect the seals for cracks and gently look under them for built up gunk from the likes of radiator sealant or rust crud. better yet if your not sure for $10 buy a new one.