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      04-09-2013, 04:13 PM   #13
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Drives: 325xi>M235i>428GCx Mspor
Join Date: Sep 2005
Location: Boston

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2006 325xi  [0.00]
Here’s my experience on changing Pads & Rotors. Hope this could help others.

• Put car on 4 jack stands (see separate DIY on how to properly jack your car up on to stands). Make sure to loosen your wheel lugs before the car is up.
• Open the brake reservoir cap (less pressure when sitting the pistons back).
• (Optional) Suck out some brake fluid from the brake reservoir with a turkey blaster….will flush brake fluid after the brake job since the car is already on jack stands with wheels off (Separate DIY).
• Take off wheel and first thing you want to do is spray some PB Blaster (lubricant) to the wheel hub where the rotor sits on and also spray some to the two bolts that holds the caliper bracket. This will make things easier later.
• Loosen the 6mm hex from the rotor, but keep the bolt on so that the rotor stays in place. I slide a hex key into the edge of the rotor where heat vents and against the caliper so that the rotor will not move when you’re trying to loosen the 6mm hex bolt (This will prevent the rotor from turning when you’re trying to turn the hex bolt).
• Take off the clip from the caliper.
• Take off sliding pin plastic covers and use 7mm hex socket to remove the caliper pins. An extension bar might be needed in some tight areas behind the rotor.
• Slide the caliper off, I had to use a screwdriver to pry the pads against both sides of the rotor (Warning! If you’re not replacing your rotors, be careful not to damage your rotors). Do not pry on the piston boot.
• Ones the caliper is off, I highly recommend hanging the caliper with ropes/hooks etc. You don’t want to put stress on the brake lines and this will also allow you to have more space to work on the brackets. You want to hang it as high as you can and away from the bracket without stressing the brake lines.
• The caliper brackets = the fun part: Do not use the Metric size; instead use the SAE size for a better snug on these bolts. I believe 18mm for the front and 16mm for the rear so find the SAE equivalent for those sizes. You will only have enough room to remove these bolts from the caliper side. This is why you want to hang the caliper to give yourself plenty of space. Be careful not to strip the bolts (use more PB Blaster on the bolts if needed).
• Remove the 6mm hex from the rotor, then remove the rotor from the hub…hammer the surface of the rotor and be careful not to hit the hub (use more PB Blaster if needed).
• Remove the old pads from the caliper and sit the piston back (I used a C clamp). Remember that the reservoir cap was left open; you shouldn’t have to use too much force when sitting the piston back.
• Now just clean the necessary parts/areas (use brake cleaners and sandpapers).
• Same process for other 3 wheels/brakes. Also replace the 2 brake sensors and install everything back (see below for more details)
• Remember to close the brake reservoir cap when you’re done.

Other notes:
• Putting back on the bracket bolts; be very careful when you torque these bolts. The front bolts are twice as big as the rears. I made the mistake of over torque one of the rear bolts and it broke. You want to properly torque them to the steering knuckle but don’t over torque. A short torque wrench is ideal for the rear (no more than a foot long). Here are the specs: Front bolt = 110nm/81ft lbs Rear bolt = 65nm/48ft lbs
• Anti-seize the bracket area where the pads sit on (the area where the edge of the pads sit/move on).
• Anti-seize the hub area.
• Use brake grease (not anti-seize) on the sliding pins.
• Use brake quiet behind the pads.
• Don’t forget to put the plastic dust covers back on for the sliding pins.
• There will be a lot of brake dust that you’ll be breathing in, use a mask unless you want your lungs to look like your wheels lol.
• If this is your first attempt, give yourself plenty of time to do this job. Don’t expect to finish in 3-4 hours; it could take 6+ hours…Good Luck!
2006 325xi (Sold)
2014 M235I (Current)
2015 428xi Gran Coupe (STB)