By your description it seems you may need to have your front rotors resurfaced or replaced. Your rotors smooth surface can over time become slightly warped from high usage or constant application of brakes (downhill). I recommend you have your front brakes inspected.
From your description, this feel you are getting sounds severe. No doubt you need to have it checked ASAP.
If this condition is consistent ONLY when you are applying the brakes, it is very likely the problem lies within the braking system.
〉 Answered on Jan 7th, 2011 by Audra Fordin, Owner at Great Bear Auto Shop
Most likely warped disc brake rotors. The rotors need to be checked for excessive run-out and machined to correct the problem. If the run-out condition is too great, the rotors will need to be replaced.
〉 Answered on Jan 7th, 2011 by Kerri Papajohn, Marketing Director at USA Sealants, Inc.
Hello Dorothy- the usual reason for your symptoms is that your truck needs new rotors- it is a very common problem with Ford trucks- they use under size rotors- Hope this helps thanks-Super Girls Auto.
〉 Answered on Jan 7th, 2011 by Laurie Sarno, Co-Owner at Super Girls Auto
Sounds like the front brake rotors need to be inspected, if they are thick enough they should be able to machine them so they are true...This is a very common problem! It may just be time for a simple brake job also...The longer you wait the more it will cost. Have it looked at ASAP.
〉 Answered on Jan 7th, 2011 by Pat Fleischmann, Director of First Impressions at Community Tire Pros & Auto Repair