Ford Repair: Ford Five-Hundred Brakes, ford five hundred, strut mounts

Question
I have a 2005 Ford Five-Hundred with about 70,000 miles on it.  For the last couple of weeks, there has been a creaking noise coming from the drivers front wheel well whenever I apply the brakes.  I've got the wheel off, and it seems to be coming from the front caliper.  Since the problem happens even at a dead stop, I'm assuming it's not the pads or the rotor.  I'm thinking it's probably a sticky piston.  My question, I notice a zerk fitting on the top of the piston assy, is that for lubrication, and if so, what type of lube can I use.

Answer
that should be a bleeder screw and should not be related to your problem.

ford has bulletins out for noise from rear relating to brakes the park brake cable is rubbing a component

the only bulletin for a squeak noise in front is coming from upper strut mounts and is suppose to only do it on turns at very low speeds

since neither one of these describes your particular problem i would have it checked out. are your brakes thin maybe the squealer is just starting to touch when brakes applied if so shortly it should start squealing when brakes are not applied and go away when they are.