Today, I replaced the front brake pads and wanted to share my notes with those that may want to do the same. First, before you do anything, purchase a 9mm allen wrench. I am 95 percent sure that you do do not have one. I spent about 2 hours trying to find it but did find one at Sears; Harbor Freight and NAPA just shrugged their corporate shoulders although both had a 8mm and a 10mm. Since the hybrid does the regenerative braking, you have to turn that off before you start. I have read that the system attempts to electrically increase the brake pressure and that this could create a lot of problems if you have the caliper off when it decides to add pressure. So first step is to turn this off. The owner's manual suggests that you can hold the brake pedal down while you turn the ignition on and off 3 times within 3 seconds and that this will turn it off. I tried seven times and this did not work for me. The service manual had another approach which involved disconnecting the 12v battery in the engine compartment and pulling fuse 24 and 31 (both 50A) from the fuse box in the engine compartment. That worked fine for me. Next problem was that both wheels were frozen to hub after removing the wheel bolts. I have my tires rotated every 10K miles, so I was a little surprised that they were frozen. Easily solved with a breaker bar used as a pry bar but shows the importance of using antiseize or LPS3 on the back of the wheels each time you take them off; I wish my Ford dealer had done that last time since it could be dificult to do if it occurs when you have a flat tire with no breaker bar. Now you have to remove a clip spring on the front of the caliper. I used a large screwdriver and a lot of pressure to remove. I wore safety glasses since the spring can pop off and hit you in the eye. To remove the calipers, you have to remove two plastic caps on back and use that 9mm allen wrench to remove the pins. My pins obviously needed greasing so I coated them with some Permatex silicone grease designed for brake lubrication. Insert the pad on the front of the disk and remove the other pad from the caliper piston since it is held on with a spring and replace with the new one. You will need to use a C clamp or a very large adjustable wrench to compress the piston a little so that the caliper parts fit together. Assemble everything including the pins, caps, and front spring. Keep the caliper suspended during the repair; you do not want to just let it hang from the brake hose. When I was finished with the repair, I reinstalled the fuses and reconnected the battery. The brake pressure pump activated as it normally does but ran a few seconds longer than normal. I became a little nervous when I noticed that the brake pedals were a little soft and the brake light was on on the dash. I remembered that there was a brake calibration process that I had to do. With the car in park, you have to fully depress the brake pedal and turn the ignition on and then off. When I shifted into reverse from park, the brake light went out and the brakes worked fine.

 

I expected to find that 9mm had a standard equivalent, since many wrenches/sockets do, but I was wrong: Standard/Metric wrench chart

I had fun trying to find a 12 mm wrench once too.

 

I am in suspense,, Where did you actually find the 9mm? was it in the library with Colonel Mustard?.
Good write up too thanks. can I assume it finally warmed up up there? We had 50 yesterday in St Louis, WooHoo!

 

Sears had two Allen wrench sets that included the 9mm. The one I bought was about $20 and they had another larger set for about $35 that had it. NAPA and Habor Freight staff tried to help but their sets skipped the 9mm but seemed to have every other size. None of the ones I had would fit. The ones that Sears had were the L-shaped and not the socket type. Of course, with the L shaped, you cannot use a torque wrench so I guessed at how tight to get it.

 

I found a Craftsman 9mm socket style at Kmart.

 

3/5/11
UPDATE! I WAS WRONG!!!!

Went to the dealer today. Would not sell me new brakes even though I asked for them. Said that the pads looked "brand new" and the wife must have already replaced them. I DON'T HAVE A WIFE!

9mm of pad on the rear and 8mm of pad on the fronts at about 124,000 miles. I'm such a gentle driver that excessive rust built up on the rotors and that was making the grinding sounds. It took a lot to wear it off. I had to get to 55 MPH, put the car in N to disable regen and force brake pads only, and stop from 55 MPH to zero "briskly" 4 or 5 times to get my rotors "clean & polished" and sure enough, all brake noise went away. Simple as that.

With gentle driving, the stock pads might indeed last the life of the vehicle.

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Just a data point.

My rear pads are gone and need a replacement at ~124,000 miles.
I started to hear grinding from the rear, and there are gentle score marks on one rear disc.
.
I'm considering doing all four just as PM.

 

I have 89,500 on my original brake pads, and they still look brand new. I guess it depends more on how the vehicle is driven (city vs highway). Previous owner on mine was majority highway, where mine is majority city (wonderful Chicago drivers have a dramatic effect on that). I bet I will be replacing them at 100,000 miles.