im not sure if its oil or brake fluid i think its oil but it is seeping out of the vacume check valve right where it connects to the master cylinder could these be from a bad plenum gasket or could the "oil" i saw in my intake be brake fluid from a bad master cylinder? i see "oil" at the brake vacum hose connection at the manifold

 

Think your talking about the booster check valve. Its a 0ne way valve as air can only be drawn out of the booster by the vacuum of the intake. Its only 2 bolts holding the master to the booster. Unbolt it a poke around inside with something see if its wet from brake fluid. 10min to find this out.

 

My money's on a failed master cylinder. They're rebuildable if you want to save some cash or just have something to tinker with on a Saturday.

 

if its a faild master cylinder is it possible that is the "oil" i saw in the intake manifold trying to see if I should address this first before I do the plenum repair because I have no other symptoms of a blown plenum except fluid in the manifold

 

I suppose it's possible, but I've never seen a master cylinder fail so badly that it put brake fluid into the intake manifold unless the brakes were almost totally nonfunctional.

A vehicle that won't go is an inconvenience, but one that won't stop is a death trap.