Background: 2004 F150 FX4 w/ 106,000 miles approx.
Symptoms:
1) Intermediate / Random occurrence.
2) Slight to moderate vibration felt in pedal when truck is stopped and/or coming to a stop.
3) Spongy feeling when applying the brake pedal.
4) Brake pedal wants to go to floor.
5) No diagnostic codes flagged and stored in onboard memory.

Due to the symptoms, could this have something to do with vacuum lines or the brake booster itself? Has anyone had or heard of similar issues and what was the corrective action?

Thanks, TurbineDave.

 

its rare for brake booster to go. sounds more like a bad master cylinder. we had a 99 e150 van at work that had the exact symptoms.

 

Thanks for the input, I was considering the master cylinder also. I plan on checking the vac lines for damage or obstruction later today. But, with my luck it probably is not something simple.

 

master cylinder isnt hard to replace. the bleeding is a pain though. going to need a buddy to help.