Uneven Brake Pad Wear

[BMW_E53]

Hey all if someone has had this problem before I'm sorry for opening another thread but I've searched and haven't found any info.

Anyways my X5 has uneven front brake pad wear between the driver and passenger side. For some reason the passenger side wears A LOT more than the drivers side and it's happened before when I replaced the pads and rotors three years ago and it's happened again. Do any of you guys know what could be the culprit? Also I purchased Genuine BMW Pads but they produce a ton of brake dust. Any suggestions for a better pad with less brake dust?

Thanks in advance!

[upallnight]

Caliper could be sticking so the pads on the passenger side is always in contact with the rotor. Did you ever rebuild or replace the caliper?

[BMW_E53]

Thanks for the reply upallnigt, the calipers are original

[StephenVA]

Yep, Really simple .
Your calipers/pads are hanging up. Which means the side that wears fastest is not retracting completely so the pad stays engaged longer and drags the pad on the rotor regardless of pedal pressure. Question does it pull to the opposite side when braking? Does the problem get worse as the brakes heat up in repeated hi speed stops. Does the vehicle pull one way on flat roads but the opposite under braking? Only one side is working, the opposite is a locked piston ,frozen in the bore.
Solution: rebuild the calipers and replace the pistons if scared. At the minimum the calipers and retaining pins should be checked, cleaned or replaced. File flat the resting points on the carriers, use appropriate caliper hi-temp grease on the caliper/carrier/pad contact points. Make sure the hoses are not collapsed and bleed the system.
. ..do not just replace the pads and hope for the best as the issue will only get worse up to and including the caliper locking up under full panic stop. Most of our vehicles need the seals in the caliper replaced at the 100k mark especially if your vehicle has not had proper brake fluid changes or has been subjected to years of use. After 10 years it's time. .......

Need a method of confirmation on the pads hanging up? Drive 30 mins with a few quick stops and measure the rotor temps side to side. The hotter one will be your issue side.

[upallnight]

Most of the time it is not worth rebuilding calipers because they stick when the piston get rusty and you will have to replace the piston as well as the seal. Piston rust because the boot is torn and water penetrates into the caliper. Once the piston surface becomes pitted you can't use them. I would just go to my local auto parts store and purchase a rebuilt caliper. When you remove the brake line off the caliper, do not allow too much fluid to drain out or else you are going to have a problem with air entering into the ABS pump. Bleeding the ABS pump is not something that can be done by a shade tree diyer.

[BMW_E53]

Thanks for all the replies guys! Based on your input it makes sense that my passenger caliper is bad so I will order the parts to replace the pads and rebuild the caliper. I shall let you know how it goes!

[StephenVA]

Being in CA, I have my fingers crossed that the calipers have NOT been cooked, rotted and full of rust from water penetration. (What is water? The vehicle is in CA!)

The trick on the caliper piston reseating is lot of brake fluid and gentle rocking of the piston during insert. I just use my fingers to set the boot on both parts (piston and caliper bore and slowly compress using hand pressure only. If it sticks just pop it back out with air pressure (using a block of wood to protect the piston and the "ears" of the caliper)

Easy
Here is a link to a similar brake project on one of my cars. Totally anal project as always......
DIY: US to Euro Floating rotors - BMW M5 Forum and M6 Forums

[srmmmm]

Originally Posted by StephenVA

Most of our vehicles need the seals in the caliper replaced at the 100k mark especially if your vehicle has not had proper brake fluid changes or has been subjected to years of use.

I've had the brake system flushed and refilled every 30,000 miles (which is 16 months for me) and never had any caliper issues. I inspect them for leaks with every tire rotation and haven't experienced any problem with them yet. I also run Akebono ceramic pads which are virtually dust free. The first set lasted 167,000 miles and my Brembo rotors have almost 250,000 miles on the Akebonos with no visible wear ridge yet.

2002 X5 3.0 314,600 miles
2014 428i 24,300 miles

2004 325i sold at 123,600 miles
2001 325i sold at 66,000 miles

1970 Firebird - under restoration

[BMW_E53]

Originally Posted by StephenVA

Being in CA, I have my fingers crossed that the calipers have NOT been cooked, rotted and full of rust from water penetration. (What is water? The vehicle is in CA!)

Lol I am hoping for the same as well! The last time I replaced the pads and rotors the boots looked ok and whenever it rains its usually just light sprinkles haha. But if there is light rust or any dirty marks, could I use brasso to clean the piston?

[BMW_E53]

Originally Posted by srmmmm

I've had the brake system flushed and refilled every 30,000 miles (which is 16 months for me) and never had any caliper issues. I inspect them for leaks with every tire rotation and haven't experienced any problem with them yet. I also run Akebono ceramic pads which are virtually dust free. The first set lasted 167,000 miles and my Brembo rotors have almost 250,000 miles on the Akebonos with no visible wear ridge yet.

2002 X5 3.0 314,600 miles
2014 428i 24,300 miles

2004 325i sold at 123,600 miles
2001 325i sold at 66,000 miles

1970 Firebird - under restoration

Thank you for the reply! My brake fluid is very old so I plan on flushing the whole system once I change the front pads! Too bad I don't have a power bleeder but I guess a two man bleed will have to do.