stuck radiator cap
 

I have a thermostat-style radiator cap that became badly corroded. I have soaked it in CLR and most of the corrosion dissolved, but I still have some crust that just won't disappear.

Worse yet, the hinged top won't open -- I can only access the radiator by taking the entire cap off.

Any suggestions on how to remove the remaining crud, and how to separate the top/bottom parts of the cap?

Re: stuck radiator cap
 

I would try soaking it in Apple Cider Vinegar for a couple of days.

Re: stuck radiator cap
 

White vinegar.

Re: stuck radiator cap
 

If you know anyone with an ultrasonic cleaner that would probably do the trick also