Is this a brake bleeder or grease zerk?

[crazy charlie]

I have not bled brakes since my 68 Corvette.My first impression were that these are for grease but then my fond Corvette memories came back to me .Charlie

 

[XS POWER]

Brake bleeder

 

[airshot]

If it were a zerk there would be a little check ball in that hole...

 

[DeepCMark58A]

you know