Unusual: rear brakes worn out; front brakes still at 50%

[Easy]

Hey guys,

I wonder if I'm the only one with this issue: I had to replace my rear brakes (and rotors) at 60K, they were completely worn out. My 2011 DJ R/T has now 72K and the front brakes are still at 50%!

Now... I know this is backwards! I believe the correct ratio is change the fronts three times and the rears once. I also know there is a flow control valve somewhere in the system, that directs more fluid to the front brakes and less to the rears, but this ratio changes if for example the trunk is full, or there are passengers in the last row etc.

But in my case, the rear brakes seem to be doing most of the work regardless.

Ever had this issue? Ever heard of a fix for it?

Thanks,

Ted

[redtomatoman]

Nope. I've never heard of that, but my rear wheels certainly do get more brake dust. Keep us updated.

Peace.

[Lobitz68]

Depends on the brake compound... Some cars still use organic compound on the rear brakes which wears out faster than a semi-metallic or ceramic pads...

[FROGBOX]

You are correct in that the fronts do most of the work. When a vehicle brakes, the weight transfers to the front so it has to brake more than the rears. This is done by a proportioning valve in the brake system. However, there are more factors to why he rears can wear out faster. The first is pad size. The rears are much smaller, so there is less material and that makes it easier to wear faster. Also, as mentioned above, the compound can be softer, also causing it to wear faster. Finally, the design of the carrier that holds the pads is different between the front & rear and I have seen it on many makes & models where the shims that hold the pads can cause the pads to get stuck so they don't float. This causes the pads to constantly drag against the rotor since the pads are not releasing fully and they can wear out faster due to that. It is not a lot of pressure, but over thousands of miles, just the slightest bit of drag will still wear a pad. That happened to my journey. I had to replace the rear brakes at 40,000 km (26,000 miles) as they were down to the metal backing. When I tried to take the pads off, I had to pry them off with a pry bar. They should just fall out. Proper lubrication of the brakes should prevent that from happening, so I do that every time I rotate my wheels.

[sexyRTboi]

thats EXACTLY what is happening to mine as i type this. My rears are gone ... had it in to get the new rims put on, than they told me it will be $460 for new rear brakes as i had about a weeks worth of driving left on the pads.

Explanation was exactly as described above by frogbox ..... poor design, corrosion, pads were stuck "ON" (which is why i have smelt burning rubber after driving some times ... had brought this up numerous times but was never told what it could be)

Im only at 58,000kms but I think we're going to do the brakes ourselves ..... put something better than OEM on there .... even a better design might be enough ... but if the corrosion is what causes it, than i may just wear through the new brakes fast too ............... damned if you do, damned if you dont.

[FROGBOX]

Its not necessarily a poor design, it just needs maintenance. There are LOTS of cars with the exact same design. The stainless steel shims are corrosion resistant. However, the steel bracket is not. What happens is the steel under the shim traps water (especially salt water in the north) and causes the bracket to rust under the shim. The rust pushes up on the shim and acts like a wedge, putting pressure on the pad, so it is no longer able to float. Simple maintenance can prevent it from happening. Simply remove the caliper, remove the shims, clean the surface under the shim and apply a bit of grease to keep out the water & prevent the rust. Then reassemble. It takes 10 min per side and can be done when rotating the tires. I do mine when I swap between summer & winter wheels.

[onecrazyfoo4u]

I just did my brakes (DJ Crew at 58k miles)...replaced them with the Callahan kit on Amazon for $150. I was very impressed with the kit for how cheap it is; they look like good quality parts with ceramic pads. We will see how long they last; but I'm sure anything is better than the stock setup.

My rotors were really warped, the whole car would shack when coming to a stop. My front pads were almost completely gone on both sides. My rears were about half gone (but the inside rear pads were worn to almost be completely gone). I don't understand how the inside pad wears out faster than the outside pad in the rears; wierd. I lubbed up all the caliper slides with new grease while I was in there; but nothing appeared to be locked up or seized. Either way, I'm glad to finally be rid of the crappy stock setup.

Took my about 3 hours total to do all 4 corners taking my time...then going for a drive to bed them in (6 hard stops from 45 to 5mph, followed by a 5 minute cooldown drive).