2004 Dodge Ram 1500 5.7 Hemi 2wd, when brakes are applied there is a high pitched squeal under dash. the more you apply pressure the higher the pitch and pedal seam to lose pressure. Need help, as this has me stumped!!! New pads and rotors, plus had a fluid flush too...

 

I am not sure about the specifics but I am thinking maybe master cylinder or vacuum leak?

 

I'm thinking mel0n is on the right track...failed brake booster is my guess.