After looking at your words you got it wrong about the rear brakes are "disc brakes pure & simple." They aren't and it's clear that you understand the system.

They are a drum in hat disc brake system. In my opinion this is a more complex system. My Mustang has a simple rear disc brake setup where the caliper has a parking brake feature incorporated into the disc caliper.

I don't get it as to why Ford chose the more complex drum in hat type system, but your answer misleads people that are less knowledgeable of automotive systems. There are two fully independent systems back there that can make trouble independently of each other.

I split for the shop manual too when I bought the car.

 

Here's that TSB: tsb09-02-04.pdf

 

Bill - Its clear you understand your system. But its also important to be very specific in this discussion.
'09s and later have shoe-in-drum style rear service brakes. An '09 and later owner could easily confuse drum/shoe service brakes with the drum(in hat)/shoe parking brake. As the TSB indicates, it is the lack of constant use that sometimes causes sticking and noise in the parking brake drum/shoes. [Your posts don't automatically indicate your model year....so I couldn't be sure in your case.]

When you say this:
...it could be confusing, because that mixes the description of two distinct braking components into one title. A title even Ford does not use.

In the '05 to '08 models......
the rear service brakes: are single piston, floating caliper, disc brakes (no drum, no hat),
the separate parking brake: is a drum-in-hat style located within the rear disc brakes

'nough said.
With the rear brake design change in the '09 (?) model year, I still think its important to be extra accurate in describing the rear brakes.

I believe the information about the parking brake sticking (that was eventually documented in the TSB) has been helpful in solving more than a few noise issues over the years.

 

The PDF version for printing doesn't list the actual release date as the TSB itself does which was in '09, I beleive in April and wasn't superceded.

 

glennb: oh come off it...

"Drum in hat" is a common tradecraft term for precisely this type of brake. Whether Ford chose to refer to it this way or not is irrelevant.

 

Tim, my 2007 Ford Escape Hybrid is in the Ford shop today, having a rear driveshaft replaced. I had noticed a sound something like the one you described, but only when I was decelerating from about 50 MPH downward to 30 MPH. I also thought it might be the hybrid battery A/C unit going bad. I likened that sound to a tin can full of marbles being spun around rapidly, and I could hear the sound coming from behind and under the vehicle, or possibly up the A/C vent from the hybrid battery in the left rear. The noise would continue until the electric hybrid system actually kicked in and the Atkinson engine stopped, then suddenly the rattling noise would stop. At the instant the tachometer dropped to zero, the ratting quit. Bizzare. Also, from 62-70 MPH, I felt a strange frame shimmy as if the tires were out of balance. I had the tires rotated and re-spun, but that didn't fix it.

The Ford shop said after it was looked at by 6 mechanics, they found that at certain speeds, the driveshaft wasn't spinning symetrically but was wobbling (like the old Hubble Space Telescope wobble) and also that "inside" the driveshaft pipe itself there was a sound indicating some broken or loose metallic part was rattling around. They also said the wobble of the draftshaft could well be the reason for the shimmy I feel when I'm at highway speeds. I certainly have hope that this is all true. This finding is good news to me because this issue has been going on for months. The bad news is that the driveshaft replacement is $1,100.

On Feb. 29, 2008, while sitting at a stoplight in D.C. in broad daylight, I was rammed from behind by a Jeep Grande Cherokee (the other driver was distracted and on his cell phone--don't use cell phones while driving, please!). It was a hard hit, then I hit a Mercedes in front of me, and he hit a Chevy in front of him, so it was "bang, bang, bang, bang!" No one was hurt, but the repair to my Ford was over $8,000 and took 73 days to complete. It's never been the same afterward, but I'm stuck with this truck because of "fear of Carfax." My theory that I'm planning to test with State Farm now, is that the accident broke/warped the driveshaft and handed me this problem.

I hope this information is helpful to you.

John B.

 

I replaced my driveshaft u-joints recently because of a vibration similar to one I have felt before on more conventional cars that were clearly u-joints failing.

As part of that I had to disassemble the flexible coupling at the very front of the driveline. This is a large diameter unit. It appears to be maybe 6 inches long. It had 6 long bolts in it. It couples the driveline to the output flange of the transaxle/PTU.

Have your Ford dealer look this over. It appears to be made of aluminum and I think easily deformed without preventing operation of the driveline. If it did deform a bit it would also give some of the symptoms described.

If pushed from the rear I believe it would crush/deform. As I reflect on it, I wondered why Ford went to the trouble of putting in this unit when there were two u-joints already in the driveline. $10 bucks says it is there to absorb a rear end push and protect the transaxle.