rear brakes are pissing me off....AGAIN!!!

[trouttrooper]

So my beast has a grand total of 68,000 miles and I have now gone completely through 3 sets of pads on the rear axle. WTF is going on here? First time I actually got the rotors and pads replaced under warranty because they were literally coming apart in chunks. Then a 1 1/2 years later I had the same problem so I personally replace rotors, pads, and calipers. Calipers were mainly because I couldn't get the damn bleeder screws to come out. During this I noticed the pads were so tight in the bracket I had to literally pound them out with my sledge hammer. I figured what was happening was the pads wouldn't release after the caliper got done pushing which 1. wore them out quick and 2. overheated the rotors causing metal fatigue. When I put the new pads on I noticed they were very tight so I ground down the tabs a little so they would slide freely.

So now here I am again, pads are completely worn out. First off, I can't get the T55 bolts out. What jackass put those on facing the spring pack so you can't get a wrench on them??? A normal metric or SAE bolt head would have been a hell of a lot better. Broke 3 wrenches including a harden steel T55 "socket". After screwing around with that mess I said F it, I'm just ordering new calipers, brackets, and pads. The rotors this time are still in good condition. However, why are the pads wearing out so fast? I have only gone through 1 set of pads on the front throughout this ordeal (I think mainly because of overuse compensating for rear brakes not working right). I don't use my brakes excessively, I'm a firm believer in downshifting and using brakes on trailer at a high percentage vs. the truck.

Is there an adjustment I'm missing? I thoroughly bled the system before, and so did the dealership the first time so I really doubt I've got air in the lines. I've done a ton of brakes on a bunch of different vehicles and this is the first time I've ever had this kind of constant problem.

Sorry, I'm venting a little. I don't have time for this crap right now. :mad2:

 

[GM Guy]

the only suggestion I have concerns re-assembly. It is is anti-seize. Permatex makes a high heat brake component specific stuff in a purple bottle. anti-seize is some pretty sticky stuff, so it shouldnt wash out very easliy.

Seeing how 496 angry cubes of big block fury is putting the twist to the driveline, I assume you are running the big 11.5" AAM that the duramax guys run? if so, I am surprised no one else hasnt had the same issue.

is it pretty salt free up north like it is down in southern Idaho? if not, do you think rust has anything to do with the issue?

 

[trouttrooper]

What's aggravating and puzzling at the same time is this. The rear brakes on the truck look like they've lived in the salt infested midwest. NONE of my other vehicles end up with this problem. They do use a ton of mag-chloride on the roads here in the winter and what I'm thinking is because I drive it so little it probably has a tendency to accumulate rust more. It is more humid here than S. Idaho but not that much.

Yup, it's a big ol axle underneath

 

[Grendahl]

One thing I've learned here in the rust belt is that road salt and rear disk brakes generally don't mix. If the slides are rusting up from the salt spray, then I'm betting that is your problem. Might want to wire brush or sand all the slides down real good and apply a good coat of high temp grease or never seize to everything that has to move. Just have to be careful not to get any grease on the pads of course. When I shop for vehicles intended for winter use I always look for something that has drum brakes on the back.

 

[btfarm]

Mike there are alot more places that need to be lubed on these than the old days. I was surprised at the wear I had on the wife's '07 Tahoe and replaced them at 45k because the factory did such a poor lube on install. I took the time to do a good reassembly and lube. They're still good now at 75k. With her's, traction controll aggrevates the issue even more though.

 

[WarWagon]

I recall some TSB's for the (I forget the exact year) 1999+ 1/2 tons to install a additional 'dust' shield for the rear brakes as dust was chewing pads off and wearing the rotors down past the cooling fins. The rotor fails at that point...

22K per pad set isn't bad. I'd go through front pads every 12K on a 1/2 ton Yukon because the worthless drum system never did much. In fact 12-15K life for 1/2 tons before the 1999 was more or less normal for any year. I hate obsolete drum systems. Now the 3/4 ton drums system I have had better luck with.

Now my 2002 1/2 ton had 48K and lots of pad life left, 2008, 115K towing and never touched the brakes except concern for noise when really hot going down extreme grades. My 2005 with only 110K has had brake work done before I bought it. So it may be 2005 specific.

 

[trouttrooper]

well, sheared apart my 3/8 breaker bar trying to remove the pass side caliper bracket bolts. Took my 1/2 breaker bar, 18mm impact socket, and 5 whacks with my sledge hammer to get the damn things off. Now have new brackets, calipers, and pads. Replaced the T55 bolts with normal ones too (I didn't care if it cost more to buy another set). Greased the crap out of all moving parts and put some antiseize on the bracket bolts. One note of interest, I think my original caliper brackets had a design flaw. the space where the pads slide is slightly smaller in disstance than the new ones and low and behold the pads don't bind up in the new brackets. May have been the cause of the premature wear. The seized bolts I'm blaming on the mag/chloride/

 

[bigdisneydaddy]

I have 94k on my truck with the stock pads. The key is to removes the stanless clips from the caliper breacket and clean them and the surface they sit against. I use a silicon brake lube under the clips and on the tabs of the pads to slow the rust. You also need to dry fit the pads before putting it all back together and make sure that they do not bind at all, you should be able to slide the pads in the bracket with little effort. This will affect the pedal feel as well as allow the pads to recenter when you release the brakes. I usually pull mine apart once a year and clearance the pad slides and relube.

 

[RI Chevy Silveradoman]

I have 85K and still on my original brakes as well.

 

[btfarm]

193k on originals. Will probably make well past 200k

 

[BigBlueChevy]

I'm assuming you already finished the job but a suggestion in regards to the seizing bleed bolt issue: Before installing everything remove the bleeder bolt completly from the bore. Put a VERY light amount of neverseize on the threads of the bleeder screw (a cotton swab works great to smear it around the threads here) and take care to avoid getting any on the spring and ball valve assembly. JUST the threads. Thread the bleeder screw carefully back into the caliper and install your brakes. I've done this to a variety of vehicles including my own, which ranges from highway princesses to dedicated plow trucks and have never once had a bleeder bolt seize up that I have installed Now if only everybody else did the same :mad2:

Something else to consider. Its not a half bad idea to disassemble your brakes once a year, clean the sliding surfaces and lube it with fresh grease. I can't even begin to stress the importance of keeping the sliding parts lubricated. "lube it or loose it!"