Sounds like a slow leak in the Brake Fliud res. or Master cyclinder leak?  
 

> Date: Tue, 9 Aug 2011 08:48:21 -0700
> From: sbw@SBW.ORG
> Subject: Leak Under Steering Column
> To: vanagon@GERRY.VANAGON.COM
> 
> I have a very slow drip of something oily from the plastic housing
> under the steering column of my '84 Wolfsburg Westy.
> 
> That can only be brake fluid, right? Or are there other fluids up
> there? It's not coolant, or I'd smell it, I think.
> 
> I haven't opened up the speedo housing yet to see whether the brake
> fluid reservoir is low or leaking.
> 
> Advice?