OP: The fact that you just did work on your suspension could be coincidental to your vibrations under braking, but it's likely that you have the fairly common "warped rotors." The OEM pads are notorious for causing brake vibrations by depositing uneven amounts of pad compound on the rotors. Many believe that warped rotors is a myth (see this post on here
http://www.toyota-4runner.org/4th-gen-t4rs/81750-pulsing-feeling-during-braking-2.html#post704764), including me. After years of racing I've yet to see a warped rotor. Here's my reasoning: when I've had "warped rotors" I've been able to "unwarp" the rotors by running a 3M cleaning pad on both sides of the rotors -- vibrations are gone. The 3M pad doesn't remove metal; therefore, I think I just removed uneven brake compound deposits.
As mentioned above, you could have a seized caliper that will exacerbate the problem by building heat in the rotors and pads and potentially causing even more odd pad compound deposits. Definitely check for that...I've had two seize. If you're not AWD, it pretty easy to check.
Basic check: Jack the wheel with it in neutral (chock wheels for safety!) and see if you can spin the wheel without the brakes on...if not you may have a seized caliper.
Double-check: Loosen the master cylinder cap and press the pads back (compressing piston), the wheel (or rotor if wheel is off) should spin. Now tighten the master cylinder cap, apply and release the brake. If your caliper is seized it will be hard to spin the rotor in the caliper. If you have a seized caliper, replace that before or while trying to fix the vibrations.
What you can do to fix rotor vibrations: Turning the rotors will fix the symptoms by literally taking the uneven compound off of the disc along with the metal. The downside is that you can only do this so often, because as the disc gets thinner it doesn't work as well (less heat capacity) and can cause more compound transfer (potentially more shaking). I think the OEM pads are prone to depositing uneven amounts of compound that causes the vibration. I've had many cars and racing brake setups. Some have had similar problems, but nothing as prevalent as the OEM pads. I keep cleaning the rotors with a 3M pad (I have one on my air grinder that makes it quick to do), but I realize most people aren't going to pull their rotors to do this, hence the typical shop turning-the-rotors solution. Perhaps someone can recommend a pad that isn't prone to this type of deposit. I've used many for other cars, but I don't want to speculate since the compound could be different in an SUV application.
My next experiment is to use a new burnishing tool that I bought to clean the rotors and put a nice burnished (cross-hatched) finish on the rotors that I hope will promote even compound deposit. I'm in the middle of moving, but when I get to it later this summer I'll make sure to post the results.
haha, I see "sonerick" said the same thing while I was typing my post....
