So my 07 with 125k miles has had new rotors for about 50k miles or so, but for a while now when the brakes get hot it gets a violent shudder on braking at highway speeds....the odd part to me is nothing at lower speeds, and not always at higher speeds....do I just have warped rotors again? The rest of the front end I good and tight....

 

Sounds like it. Sometimes you might not feel the pulsation, the harmonics are just right. Steering wheel nibbles back and forth, or do you feel it in the seat?

 

It's just in the wheel....it also seems like the truck pulsates the stopping power. Hard to explain....guess I need new rotors.

 

Just a slight correction,

The rotors are warping as a result of being heated unevenly....and as they cool, they "straighten" out so to speak. not unusual with the al based composite materials used in many of the rotors today, but if I may offer a little fyi......

I use OEM replacement rotors that are cryogenically treated at Diversified Cryogenics, making them almost as hard as stainless steel- Applied Rotor Technology in California provides the same product- but I would not rely on their delivery as it is essentially a 1 person shop owned/run by a Boeing engineer who works back east, travels alot and works at ART on weekends the last of my phone conversations with him). Unfortunately, Brembo, Powerslot, Raybestos, Bendix, Hawk etc. are all purchasing their rotors from the same foundary in China (with the exception of the $300 each composite high end units for Ferrari, Porsche, etc).

Both companies purchase the highest grade rotors made, laser mic them for quality, scrap the ones that are out of spec and cryogenically treat the good ones which are now as strong as stainless. DC's service, price and quality are excellent as well......and they typically run about $20 each more for the tx.

 

What brand of brake pad are you using ?

I have learned its not the rotor's so much as its the brake pads inability to shed the dust.

Do your rotor's have sign's of a the outline of a brake pad on them ?

I use Hawk pads on my cars and no longer have the shimmy in the steering wheel under braking at high speeds.

Sometime you can clean the rotor's off by "re-bedding" the brake pads. But that seems to last for while, until the pads build up dust again.

If you buy good pads like Hawk the problem should go away.

Hawk LTS Front & Rear Brake Pad Sets=

 

Replaced a set of warped front rotors. Right after leaving the shop the pulsation was still there. Found out the cups in the calipers were sticking and keeping the pad on the rotor. Ruined a new set of rotors.

 

I'm surprised the tech didn't notice that when he tried to compress the piston back into the caliper.

Prior to that did you ever noticed the brakes smelled hot when you got out of the truck ?

Were your wheels getting dusty, quickly ? Those are indications of a problem.

Just asking.

 

I have no dust hardly....I've got napa premium rotors and napas top of the line ceramic pads on it. The calipers don't seem to be sticking, the usual signs of pulling are non existent and the cups compress smooth as silk.

 

I was about to jump on the pads until I read about the ceramics, that's the way to go for sure. Also from experience and I also use Napa it's UAP Napa in Canada. save your money on the premium rotors they are all junk mid grade work just as well mine have been on the truck for three years now. What I suspect is your problem is the pins are seized not allowing the calliper to "float" with the rotor so you are basically stopping on one side of the of the rotor. These pins will work as they should if they get wet then they seize up again. Sort of good one day and not the next, I have my callipers checked twice a year pins removed cleaned and new ant-seize compound installed and reassembled, it's a pain but no problems and I have even wear, great stopping power and no annoying brake squealing but I contribute that to the ceramic pads.
Hope this was a help
Robert in Canada

 

You may want to bring this up with the guy at NAPA. May be one of your pads is not bonded correctly, the heat cause it to move a bit, I'm just guessing.

You may want to verify the pins are free like this guy say's.



When I replace the pads on my GF's 08 Escape, I had the stock rotors re-surfaced on a surface grinder like a Flywheel is cut and used NAPA ceramic pads.

I also lube the slider pins. That truck stops nicely.