Juddering Brakes

[Gary Waugh]

Guys, I wanted to ask for your opinion, about a year ago my 08 expedition started juddering every time I applied the brakes (it has done more than 200K miles and was on original rotors). I decided to check the pads and rotors and everything was within spec, but the rotors where close to the minimum thickness, so I changed all 4 rotors (front and rear), didn't notice any change to the braking and still had the juddering every time I used the brakes.
I though there must be a worn wheel bearing or track rod end that was allowing the front wheels to wobble when braking, but I could not find anything wrong.
In despair I took the car to my local garage (who I trust) and they gave it a quick mechanical check then hooked up their computer and announced the ABS was malfunctioning and causing the juddering. The check engine light does not come on and my ODB reader does not see any codes (for the brakes or any other system).

I don't know if ford still supplies ABS units for a car this old, and I know it will cost an arm and a leg if they do.. But I have never heard of an ABS unit causing juddering, does this pass the basic sanity check? the garage said the ABS wheel sensors all appear to be good and are providing signals to the ABS unit (I guess if one failed the ODB system would flag it)!! The garage are now looking at what options I might have to repair the issue, but I just thought I would ask for ideas on this site first!!
The car runs great, everything (except TPMS) system works perfectly, the engine and transmission use no oil at all, it doesn't smoke when driven so I want to keep it, but I suspect the ABS unit will be $1500+ without installation, however I feel it's worth spending the money as the car has been so reliable (it has had 1 started motor and 1 T piece in the cooling line fail in 15 years and 220K miles!!) so a great car.

What do you guys think, have you heard of an ABS unit failing and causing juddering when braking without reporting any error codes?
Do I buy a new ABS unit (if available), or do companies sell refurbished units? What kind of guarantee do they give? I assume the ECU has to be programmed to recognize the new ABS unit so this is probably something I have to leave to the garage to do?

Cheers Gary

 

[Retiredusps]

On the wifes 2005 it turned out to be front calipers and rubber hose from frame to caliper.only did it down hill with light pressure on pedal

 

[Gary Waugh]

the first thing the garage said was warped rotors or calipers, they checked both and said all was good and then dropped the bomb that it is the ABS unit!! A caliper would have been a lot cheaper and easier to fix!!

 

[Gary Waugh]

One other question, I will look in the owners manual, but can anyone tell me if the 2008 ford expeditions had a separate fuse for the ABS unit? I would like to remove the fuse to temporarily disable the ABS unit and then see if the juddering disappears, if it does then in my mind I have proven it really is the ABS unit that causes the juddering, if the juddering is still there with the fuse removed then it would suggest something else is causing the juddering.
Also I see several re-manufactured ABS units for the ford expedition for less than $500, can anyone recomend a good company to purchase from?

 

[GlennSullivan]

I had the same problem with my 2011 2 years ago. I went through the same troubleshooting process as you (Rotors, front end, etc) as it is VERY COMMON for Expy's to have front end shutter when they need the rotors cut or replaced. Same as you no codes at all

Rotors not the problem this time, Ended up changing both front brake hoses, which was a big improvement, but did not completely resolve the issue. Then finally the ABS controller, which completely resolved the issue.

To potentially save yourself some money, first change both front brake hoses (hard line to caliper) and thoroughly bleed. If that resolves it, you are ahead of the game, if not, you will need to change the ABS controller.

Looking at Tascaparts.com, it appears that both modules (with and without stability control) may still be available. I've also heard that some companies will rebuild your existing unit, but don't have any experience with that.

 

[purevw]

You stated the vehicle has 200,000 miles. I can't find the schedule for my Expy, but my Grand Marquis suggested a scheduled front bearing hub change at 160,000 miles. The Expy schedule shows bearing and hub inspection at 150,000 (for vehicles with replaceable bearings and seals). Worn bearings can easily cause brake behavior problems.

 

[Texas Dave]

I am having the same problem with my 2007. Just over a year ago I had a brake shop change out rotors, calipers, etc. The ABS light started appearing intermittently a few months ago then went away. Like you, I get no OBD codes. I can feel a pulsating brake feeling along with the shuddering.

 

[Gary Waugh]

I went and pulled the 2 ABS fuses (ABS pump & ABS valves) and almost all the uddering has disappeared, there is a little juddering so I migh still have an issue with a rotor or caliper, but I think my garage was atleast 80% correct when they said it was the ABS. Unfortunately I will now be looking to replace the ABS control unit and then see if I still have a judder or not. My 2 ABS fuses were located in the fuse box that sits under the hood on top of the main radiator, they ar described as fuse modules and are rated for 60 amps each.