I'm pretty sure you are looking for the awesomeness that is lostatc from fanfiction dot net. She has an entire Ben Braedon series that starts like this. Here's the link to her stories page and in her description, she lists the stories in order in that series. The second one, 'to the rescure' is the one where Ben calls for Dean to come.

This was the very first series I ever read in fanfiction and it holds a special place in my heart. Lostatc is a completely, utterly fantastic writer.

http://www.fanfiction.net/u/1277402/ - Lostatc homepage.

'To the Rescue' - http://www.fanfiction.net/s/3844134/1/To_The_Rescue