You can't bleed a steam radiator. It relies on air moving in and out through the steam vent valve to work. Bleeding is done on hot water radiators.

I think the problem is being caused by the valve not closing after the steam rises to the top of the radiator. A simple cleaning my fix the problem. Below is a link how to clean the valve. It that does not work then the valve needs to be replaced. Be careful when you unscrew the valve. If don't want to break the stem.

Here is a link that might be useful: How to Clean a steam radiator air valve