While under the engine greasing all the fittings on my 97 2500 truck, I noticed for the first time, zerk style greasing fittings on top of the brake housing, right up above where the brake fluid line comes in to the housing. I have never noticed them before and they look brand new. I had a complete brake job earlier in the summer and am wondering if they installed them. Am I supposed to grease these? I can't imagine why you would. Any thoughts. Thanks