# Sudden & abnormal brake pad wear (thoughts?)



## mbeers (Jul 27, 2016)

Just noticed some very abnormal and sudden front passenger side brake pad wear on '12 Eco. Both driver side pads still has maybe 8mm left but *passenger side outside pad is almost gone *(inside pad not too bad...see pics below).

Only thing I've done recently was pressure bled the brakes using canister attached to master cylinder. Car has 104k miles on original brakes and I checked the pads not more than 4k miles ago. 

Some items I looked at and considered :

-Guide pins both moved freely and still lubed well. 
-Caliper piston has some grime but nothing too bad. 
-Car wasn't pulling when braking
-Outside pad wasn't wearing unevenly i.e. top more than bottom.

Could it have something to do with pressure bleading the brakes? Only other thought is that the metal circlips might have had road grime but would have cause outside pad to wear more than inside pad? 

I welcome any thoughts.

Passenger side *outside *pad (opposite side of piston)


Passenger side *inside *pad (rests against piston)


Guide pin looked good (shows piston after I cleaned it)


*Drivers side outside pad* *for* *comparison *(both inner & outer are same).


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## obermd (Mar 3, 2012)

Are the pads balanced on the inside and outside? By this I mean when you apply the brakes do both sides get the correct force. It's possible the one side is taking all the braking force on that wheel.


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## mbeers (Jul 27, 2016)

obermd said:


> By this I mean when you apply the brakes do both sides get the correct force. It's possible the one side is taking all the braking force on that wheel.


Thank you for the response and good question, how would I check/confirm that? Could I just remove the wheel and have wife press brake pedal and see if both pads move the same amount & at same time?


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## Patman (May 7, 2011)

Honestly the pads don't look that worn esp for 104K miles, must do alot of hwy driving. I had a seized caliper on my 2012 Eco several years ago that wore out the driver side pads. Passenger side was OK, I just changed the pads and by resetting the caliper on the drivers side it resolved the problem. I would go ahead and compress that caliper with a C Clamp, re install the pads and bleed the brakes as well as adjusting the rear brake shoes.


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## eddiefromcali (Aug 21, 2017)

maybe something in the pad material? meaning that you might have started wearing out a "softer" part of the pad?


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## snowwy66 (Nov 5, 2017)

I'm not aware of any technique to check the force on pads. 

It's a pretty common problem. All you can do is make sure everthing is clean of rust and lubed. All moving points. 

What you CAN check. Is piston freeness. It's possible 1 or the other caliper is freezing up. OR, you may have a proportioning valve problem. Causing 1 side to work harder then the other. It's possible the 1 side is working while the other is not. 

As mentioned above. Take the cap off the brake reservoir so you're not building up pressure when pushing the fluid back in. Use a C clamp to compress the piston back in. If both are easy to compress then the system is probably in good shape. Unless someone else has an idea. If 1 is harder to compress then the other. That piston is starting to freeze up. Your choices are to either take apart the caliper. Clean up inside and replace the piston seal. Or replace the caliper. 

It's best to do both sides as a set. If you only replace 1. It's just a matter of time till the other one starts to freeze up.

If your state or any shops have a brake test machine. You can have them check your hydraulics. They run on the machine at a slow speed and slam on teh brakes. The machine measures the effectiveness of all 4 tires. And prints you out a chart. It'll also measure your alignment. 

I took my car in to dealer at 500 miles for the oil change and they ran it over the machine. I"m right at the border of out of spec. When the weather warms up. I'll give it a slight toe in adjustment.


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## mbeers (Jul 27, 2016)

Good input here. 

Once my new rotors and pads come, I'll just go through everything making sure proper components are lubed, etc. My guess is that since these are the original brakes with 104,000 miles the pad might have gotten stuck against the rotor due to dirt/lack of lubrication where they rest against the metal shims. In hindsight I should have cleaned and lubed everything periodically but oh well glad I got 104k miles out of the stock setup!!!


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