Aaron,
As others have stated, that is a bleeder, not a grease point.
The areas that need cleaning and greasing are the sliders that hold the caliper to the hanger.
Each caliper has two of them and the rubber boots should be checked for cracks while you are at it.
The front wheel Vanagon brake system is a really easy to clean and freshen up.

Best of luck.
Thank goodness you asked before pumping grease.

dylan

________________________________
From: aaron bright <vdub4uandme@YAHOO.COM>
To: vanagon@GERRY.VANAGON.COM
Sent: Sunday, September 13, 2009 10:15:05 AM
Subject: Little bit of brake capliper info.

I was changing out my pads and just cleaning up my brake system and noticed what I thought to be a grease fitting on the back on my caliper(??) just wanted to make sure that it was a grease fitting before I shoved grease in it.� Thanks for the help
�Thank you,
Aaron Bright
Louisville, KY