So when I press and depress the brake pedal, it makes a low sqeak. Not too high pitched but it just sounds like somethings not lubricated. I looked under the dash and its coming from where the metal rod goes through the firewall. Not from the spring/fulcrum (pivot point) of the pedal. Any help?

 

What year truck?

It could be something in the booster, it could be the master cylinder. It might sound like its from the booster but its the MC and it resonates through the booster.

How old is the brake fluid? If its really old you might have some contaminants or whatnot that cause the master cylinder to squeak. Use a turkey baster to suck as much brake fluid out of the reservoir as possible. Then fill it with fresh fluid and bleed the system to move the fresh fluid through the lines.

Use the Ford OE fluid... it has good lubricity and should stop the squeak (the fluid GM uses does not)

If it still squeaks, it is probably the booster. DO NOT USE WD40 or any other oil... the components of the booster (EPDM rubber) do not get along with mineral oils. They will swell up and you will trash your booster. You can try some silicone spray, but use it sparingly.

 

I have the same issue. Did you find the problem?

 

I have not found the problem. I had my very trusted mechanic look at it and he said that it was coming from a bushing (and nobody call my mechanic out on this cause I'm not 100% sure I remember exactly what he told me) that is on the outer portion of the assembly and that in order to get to it, I would pretty much have to completely tear apart and basicly replace the pedal assembly. He said he's seen it on a few Fords and so far no mechanical problems caused by it besides a little annoyance to the driver. He said not to worry about it cause it really wouldnt be worth the cost to replace. Mine actually comes and goes. Sometimes for a month or more at a time I can go with no noise. Then it'll come again for a day. I'm just not going to worry about it though. Good luck.