PontiacBonnevilleClub.com

My rear shoes finally need replacing. I was surprised they lasted this long. The rear brakes are all factory and have never been replaced. The springs however did not survive. The parking brake spring has turned to dust (literally). The funny thing is...is that my braking is still very good. Replacing the shoes and drums tomorrow. I'm still shocked that these shoes and drums still made it this long. The Bonneville never stops impressing me.

At least your rear drum brakes work. I have an '84 and an '86 that don't. I kid you not, 300,000 on my '84 K2500 with original rear shoes, no wear at all.

MattStrike wrote:

At least your rear drum brakes work. I have an '84 and an '86 that don't. I kid you not, 300,000 on my '84 K2500 with original rear shoes, no wear at all.

I'm seeing this with more and more cars... the braking seems to be 98% front, 2% rear. The rears work on my Bonneville (been using the parking brake A LOT while changing my brake lines), but IIRC, I've never changed them in 229K. I check them every 50~60K to be sure everything is kosher. I'm also seeing this with the '98 Sunfire, '04 GP and a '99 GP. All seem to work fine, but never wear... the Sunfire will get rear shoes Real Soon Now _ONLY_ because they got contaminated and everything inside is a mess.

BKNJ

For those that aren't aware...MOST service drum brake systems need adjustment every 20 or so thousand miles to maintain their proper application positions, otherwise you're stressing out your front brakes, possibly causing overheating/warp age and additional wear, and you're not getting an evenly distributed stop. If you don't feel like doing the adjustment yourself that often (it's really just making sure all the springs are ok, removing/cleaning and adjusting the adjuster and checking the wheel cylinder condition) most repair shops will do it for you for $15-30.

To correctly check for adjustment, you can raise the back wheels off the ground, and spin them. You should have some spin, but they should stop spinning after 1-2 spins. If they keep spinning, you need your drums adjusted.

Rear drums are also supposed to auto-adjust. There is a ratcheting mechanism in them that tightens the brakes every time you use them in reverse when they get too loose. I've seen how well this works: It's perfectly fine in our '99 Montana, our '91 olds ciera, the '93 bonnie.

MattStrike wrote:Rear drums are also supposed to auto-adjust. There is a ratcheting mechanism in them that tightens the brakes every time you use them in reverse when they get too loose. I've seen how well this works: It's perfectly fine in our '99 Montana, our '91 olds ciera, the '93 bonnie.

I have adjusted my rears manually when I was doing tire rotations on my own in between rotations at the dealer where they're included with the tires I bought.

But somewhere I picked up that the mechanism only worked when backing up and applied strongly AND after a solid application in forward to move things. So I have tried doing a hard stop forward, followed by a hard stop in reverse, then forward... I have done it on my residential street but most often in an empty church parking lot. The hard applications did tighten up the rear bands. The applications were hard enough the ABS light sometimes came on.

MattStrike wrote:Rear drums are also supposed to auto-adjust. There is a ratcheting mechanism in them that tightens the brakes every time you use them in reverse when they get too loose. I've seen how well this works: It's perfectly fine in our '99 Montana, our '91 olds ciera, the '93 bonnie.

Supposed to IF the adjuster is clean and lubed up...but it still is within normality to pull the drums and say hi to the brakes every 20k or so.

MattStrike wrote:Rear drums are also supposed to auto-adjust. There is a ratcheting mechanism in them that tightens the brakes every time you use them in reverse when they get too loose. I've seen how well this works: It's perfectly fine in our '99 Montana, our '91 olds ciera, the '93 bonnie.

Supposed to doesn't mean they do. Even on brand-new cars, the drums still needed manual adjusting. The drums were far out of adjustment on my Cruze and the wife's Fit from the factory. They both needed 10+ clicks of the star wheel on each side to be properly adjusted. That was after a lot of reversing, too.

I completely overhauled my rear brake system about 23,000 miles ago at around 95K or so. Never touched a thing before this overhaul. New drums, shoes, springs and wheel cylinders- even replaced the steel brake lines. Over time I would try and keep them adjusted by backing up and applying the brakes multiple times. This resulted in a slight but noticeable improvement albeit short lived.

Recently, I heard a scraping noise from one of the rear brakes at low speed. Spinning the wheel after jacking up the car, you could hear the brake shoe scrapping.

I took the car into my trusted mechanic to check it out and he said the rough patch on the shoe was normal and all the brakes needed was cleaning, lube and adjustment. I told him I just adjusted them and do so regularly by backing up. His reply was that "does absolutely nothing".

The truth is, he was right. My brakes are now working like never before after he adjusted them. Better than when I first overhauled them and AFAICT, better than when new. The stopping power of the system is like night and day. It feels as if the rear brakes are doing about 35% of the work now.! A huge improvement.I highly recommend having a mechanic that knows how to work on drum brakes adjust them at 20K mile intervals ( save advice as the OP in this thread gave)