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Rear brakes wearing out faster than front

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24K views 35 replies 13 participants last post by  ColdCase  
#1 ·
Just took my 2012 Grand Cherokee V6 4x4 in for an oil change, and was told that my rear brakes are almost worn out, but my fronts still have plenty of life left on them.

The Jeep only has 16,000 mi. on it and the rear brake pads only have 3mm left while the front pads have 7mm per the technician.

There were no signs of the calipers sticking or getting hung up.

Shouldn't the front and rear brakes wear evenly, or at least the fronts should wear out faster than the rears because they do most of the braking?

Is there a proportioning valve on this system that maybe isn't set properly?

Any ideas what might be causing this?
 
#2 ·
Your Jeep in normally in RWD and with ESP and traction control the rear brakes will wearout faster then the fronts with those driving aids.Even if you don't know it or feel it those rear brakes are engaging more often then you think.
 
#10 ·
????



My 2012 Grand Cherokee Laredo X AWD with the ORAI package is in RWD normally??? Really? And you are a mechanic.

If OP's rear brakes are wearing out there is a problem. Either with driving style or more likely a failure of some component.

The front brakes of most vehicles do approx 70% of the braking. You do not want the rear brakes doing much more than 30% because then you run into all kinds of balance and handling issues. Race cars have an adjustable proportioning valve you use this compensate for wear, weather, and track conditions.
 
#8 ·
Is there a proportioning valve on this system that maybe isn't set properly?

Any ideas what might be causing this?
Well the parking brake uses the drum, not the pads... so someone hasn't been driving with the parking brake on.

The service manual says they use a Electronic Variable Brake Proportioning designed into the combined hydraulic control unit and ABS module which eliminates the typical combination/proportioning valve. Its a four channels sytem with each caliper directly connected to the HCU. As far as I can tell there are no manual adjustments, although the dealer's scanner may have some kind of capability.

I would suspect something amiss in the HCU/ABS module or perhaps sensors. Perhaps the control system thinks the rear tires are spinning faster than the fronts, and are routinely applying the rear brakes.

Unless you have someone riding the brakes, 16,000 miles is a bit short.

Rears brakes use smaller pads and are lighter duty than the fronts, so they could wear faster than the fronts. Our WJs alway wore fronts twice as fast as the rears, however.

There are a number of things that will cause brakes to be applied automatically, yaw, stability, wipers, along with traction.
 
#9 ·
Did you get this sorted out?

While perusing for another issue I ran across the reminder that the master cylinder has two pistons, one for fronts, one for rears and this proportioning description. Both my front and rear pads have plenty left after 36,000 miles mostly highway. Hard to tell if one set is wearing faster than the other.
 

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#19 ·
The rear brakes on my 2012 dodge charger pursuit wear out before the fronts. The fronts wore out before the rears on my old ford crown vic. Esp vs no esp.

The rear brakes are worn more than the front but are still at 50%+ on my wk at 67k miles.

I have seen some newer cars apply the rear brakes before the fronts in the mountains or on snow. These days though its pretty tough to notice the lag between the front and rear brakes.

At pursuit driving schools i have been told ( cant confirm) that as cars get newer the designers put in a small amount of rear brake bias for stability when braking above 55 mph. When the brakes are heated after multiple laps you can feel the rear brake shimmy on high speed stops with larger pursuit vehicles like the charger, tahoe, and new ford interceptor suv.

Just my observations.

Plus the local wrench who i go to commented on lots of newer cars needing rear brakes before fronts.
 
#20 ·
????

At pursuit driving schools i have been told ( cant confirm) that as cars get newer the designers put in a small amount of rear brake bias for stability when braking above 55 mph. When the brakes are heated after multiple laps you can feel the rear brake shimmy on high speed stops with larger pursuit vehicles like the charger, tahoe, and new ford interceptor suv.

I have spent a lot of track days braking from 120mph+ for turn 1 at Summit Point down to 40mph give or take. I also handled suspension and brakes for a SSCA GT3 car and a Spec Racer and you dont want any rear brake bias at speeds above 55mph. You can adjust the bias for rain etc but you never want it biased to the rear since it will result in a whole lot of fun.

If the rear brakes shimmy on high speed stops then the vehicle has design problems or brake issues have developed from improper use. For example not letting the brakes cool completely after track sessions or doing something really bright like engaging the parking brake after hot laps.
 
#26 ·
This is a VERY common issue in the JK Wrangler as well. It's because of a combination of the traction control, ESP, and brake compound. Not unusual in Chrysler vehicles these days it seems. More so in the ESP programming in the JK. If you drive in snow or other slippery conditions, the brakes are applied to the rear wheels quite often to help prevent an oversteer condition, ie going around a turn in snow covered roads, like turning at an intersection. My '08 JK's rear brakes needed replaced at 14k.
 
#28 ·
Thanks for all the input everybody. Took it back in to the dealer to inspect the brake system and it turns out the idiot who inspected them the first time was wrong and I have a lot less wear on the brakes than they originally told me. The rear is slightly more worn than the front, but the service manager basically confirmed what has been said in this thread, that it is normal on these vehicles for the rear brakes to wear out faster than the front due to the traction control system.

Thanks again, not sure if I would've beleived him if it wasn't for y'all. :cheers2:
 
#29 ·
Hmmmm... another advantage of the QD with ELSD perhaps? For those who are looking for another rationalization for the expense, brake traction control is not used (or needed) on the QD ELSD axle (rear).

I wonder if QTI eats up more brakes than QTII as the QTI transfercase is completely open, only brake traction control to shift power to another axle where QTII's transfercase shifts the power between front and rear.

I've always heard brake traction control eats up brakes on the typical open diff vehicles, especially during any slippery off road excursions.
 
#30 ·
I wonder if QTI eats up more brakes than QTII as the QTI transfercase is completely open, only brake traction control to shift power to another axle where QTII's transfercase shifts the power between front an rear.

I've got just over 6000 miles on my 2013 GC with QT1. I've been shifting and flying around a bit, even got a little slide when I got all 4 tires wet (got to love emply lots). I will let you know if they have the same wear problem.

I need to get the hot rod out of my system before I get all terrian tires, yeah right.
 
#31 ·
I have a 2013 10th anniversary Rubicon, no complaints on this end. The machine is much better than I imagined. It replaced my 2004 Rubicon. When slippery (which was most days this winter), and a bit heavy footed on the throttle, the traction control light comes on, engine cuts back, spin ends. I assume a brake likely came on for a wheel somewhere. Question: Is it safe to say that anytime that the computer applies a brake to stop a spin or skid that you should see the dash light come on???
This has been an interesting read. If nothing else ...... it explains the low gas mileage (computer riding the brakes!). None of us bought the Wrangler to brag about mileage anyway...............
 
#33 ·
Yes, anytime it applies the brakes the light will flash, the exception being if it is using one of the brakes to slow down a spinning wheel off road with the traction control shut off. With it on it will pull throttle and use the brakes to transfer power, with traction control off it will just use the brakes. The only time you would run into it is if you are in 4 wheel drive without the lockers engauged though.
 
#36 ·
Just as an aside, the WK2 applies a bit of brake when its raining to keep the rotors/pads dryer. When you suddenly lift the throttle, the ABS thinks you are going to want to apply brakes, so it starts to do so in anticipation. All this brake use contributes to pad wear, dunno how much.