Trapper

Sounds like you've found your problem. For most DIY mechanics, this is a job that most cannot do. If you can rebuild an engine or a transmission, you can change the rear bearings and seals. Here's a DIY article for a 2004 YM. Yours will be similair:
http://www.f150online.com/forums/art...lots-pics.html

For the surging brake pedal, you'll need to replace the rotors which have to come off anyway. Might want to consider these as they have a lifetime warranty. They also come with free standard pads but I'd suggest a cheap upgrade to the semi-metallic.
http://brakeperformance.com/site/bra...d1c22c43288fa3

FX4_GUY

Well Trapper I can rebuild an engine ( In my time I have rebuilt a 302 a chevy 305 and a whole bunch of 350's .. But that has been 20 some odd years ago.. I just got thru changing out my front wheel hub bearing assembly's , my cv shafts and brakes on the front .. This was all simple .. I gues the biggest scare I have is that I can get it apart but might not be able to ge it back together... Plus I will be doing the wrok with Jackstands and out in the open on concrete.. I may let someone else do this but I no I am going to get ripped on labor.... Thanks for the pics sight , that doesn't look as hard as I thought .. This will be my first time to work on any rearend of any vehicle.

FX4_GUY

Oh I forgot to mention I know why the seal is leaking and the bearing failed.. When I first bought the truck the tires were summit mud tires and they were awful, and to big .. this probably put stress on the bearing ... Also the vent tube at the top of the drivers side rear axle was clogged with so much dirt and so rotten when I got under the truck yesterday The vent tube had come loose , both the vent tube as well as the actual hose were packed with dirt.. I blew out the hose and then used a coat hanger wire to clean the hole on the axle .. I may work on it a little this afternoon but I have a job at 9 AM this morning

FX4_GUY

Well I pulled off the tires on the rear ,, cleaned everything with brake cleaner checked the seals and they look fine , then I was thinking Maybe the oily stuff is Brake Fluid .. Anyway I cleaned everything up and put it all back together No Leaks at all.. Hmmm must have been that stopped up vent tube .. Now the noise is still there and a slight vibration... The brake problem seems better.. ABS light is still on and the brake pedal feels a little stiff.. And this evening we got a ABS fault code B1342 codes, says ABS control module defective

FX4_GUY

Ok get ready this will be a long one.. Well I took my truck to the ford place and they ran the ABS light code.. Sure enough I got a bad front wheel bearing from Oreilly.. Soun I put a new one on.. I was also told my u-joints were bad , so I changed them out as well.. I also put my new shocks on the back of the truck , already have new ones on the front ... I also changed out all my brake pads ..and bought 4 new rotors.. The Ford place said the rear wheel bearings were fine..I cleared the KAM Memory .. don't get mad like I did but I got in the truck and drove it down the road and the ABS Light came on again and now , the brakes shake the mess out of the back of the truck when applied and the front new bearing is roaring at about 35 to 50 mph.. and as I gradually brake it feels like my front brakes are trying to lock up .. So this morning I went back to the Ford Place and I was told that obviously I had no idea what I was doing and that they have never heard of problems this extreme with the wheel bearings and such.. I am about at the point where I may have to take out a second loan just to get my dang truck fixed.. I have done all I can do , Unless those cheaper Orielly hub bearing assemblies are just crap.. But they are not lasting 4 weeks if thats what it is..

Broncomanjoe

Im having a similar problem with my moms 2003 Heritage ED It makes a humming almost grinding noise from 30-45 MPH .I replaced the two rear U-joints axle seals and bearings and still the noise I looked in the bottom of the rear diff and found some larger than normal metal shavings so my next thought is the Pinion bearing or one of the others. However when the brakes are applied and shifting from drive to reverse there is no clunk or movement which I thought was strange? So what did the problem on your end up being seeing as it was posted some time ago?