I've got a strange noise that started a couple of weeks ago on my '04 F150. When depressing the brakes hard, you hear a 'creaking' noise coming from the pedal area. I can be at a dead stop and alternate pressing hard and harder and it groans like crazy. It is so annoying, my wife fussed while I was making the noise.

It is definately not coming from the pads, rotors or anywhere around the drive train. It appears to be coming from whatever is under that rubber boot which connects from the pedal and goes thru the firewall and into the brake booster / master cylinder. I got a long nozzle and sprayed some Kroil lubricant into the boot. It didn't do anything for the noise and only made the interior stink.

No difference in braking. Just the annoying noise every time you press the brakes. Something going out? Any ideas? Anyone else had this problem?

Thanks.

I have an 04 as well and mine started to do the exact samething a few weeks ago as well. It is definelty not coming from pad or rotors all mine are less than a month old. It's somewhere down by my feet. Same as yours-No braking difference just the noise. I'd really like to find out what it is?

Sounds like a job for WD-40, get up under there and just start spraying, always works for me.

Could be the brake booster or the master cylinder. Mazda had a recall for a brake noise similar to that. The fix was changing the brake fluid. I don't know why, but it did fix it. I know there is a difference in the parts between the ford full size trucks and mazda cars, so don't flame away. I'm just offering another possibility.

Yeah I was thinking the same. I'll finally have time to look at it tomorrow, I'll see what WD-40 does

i have the same problem tell me how it turns out bucs.

just a suggestion. use something like lps 1 or 2. something that lubes. wd40 really doesnt cut it for lubing. maybe penetrating.

DO NOT SPRAY OIL
The booster uses EPDM diaphragms. Mineral oils cause EPDM to swell and can cause lots of issues that will require you to replace your booster.
(BTW - EPDM is used for a good reason - brake fluid is a nasty thing and EPDM can stand up to it)

Its hard to diagnose this problem based solely upon the description. This is one of those cases where first-hand information is a must.

That said, I would think the issue is likely related to the booster - as you apply the brake pedal, the booster will suck air in from the truck cabin. This method is used in almost all vehicles (some top-end vehicles suck the air from the engine area, but then they need filters and whatnot). This is normally described as a "whoosh" noise. But if something changed, it could probably "groan" or "creak". Again, I can't really say what it is based on the description.

There is also a possibility that the seals in the master cylinder are creating a noise.

I just noticed that you said it happens when you press the pedal hard. You might simply be hearing the booster shells flex when you really romp on the brake pedal.

Guys - thanks for all the replies thus far. What was written above definately makes sense as the rubber boot has what appears to be a small breathable non removeable filter that would allow air to pass. This is the area where the noise is coming from. I may already be screwed since I sprayed a good shot of Kroil in there. I tried to remove this 'boot' from the passenger compartment but it apparently is fastened from the booster side. Not a 'whooshing' noise. Definately a groan or creak.

I mentioned it occurs when I press the brakes hard. I should clarify. It does it with routine stopping, it just starts the creaking at the point when you are completing your braking and are pressing the pedal harder than when you first start to brake.

Thanks.

sounds more like linkage or at a pivot point

that could very well be the case. You can oil the parts of the linkage (I'd use silicon). Just don't go crazy, and wipe off any excess so it doesn't run down the rod into the booster.

rcknrbn - you could be ok, or you could be screwed. It depends on whether enough oil works its way through the components to make contact with the diaphragms. If you start to get weird brake pedal feel, I'd look into replacing the booster. (better to spend $ on a booster than loose boost and not stop quick enough to avoid hitting something!)