Rear brakes won't wear out

GMC FAQ » GMC Sierra » Rear brakes won't wear out

Question:

I’ve got a ‘92 Sierra. I have 91,000 miles and I’m still on the origional rear brakes. I Keep checking them, and they still have a ton of pad left. I changed the fronts at 60,000. a friend at work has the same truck (‘93) with 150,000 miles, and he still has the origional rear brakes too. Does this tell you something about GMC brakes. THE REARS DON’T WORK! He has had his to the shop a few times asking about them, and he gets the same dumb answers… "there’s nothing wrong with your brakes" Anyone else have this problem?

Response:

> I’ve got a ‘92 Sierra. I have 91,000 miles and I’m still on the > origional rear brakes. I Keep checking them, and they still have a > ton of pad left. I changed the fronts at 60,000. > a friend at work has the same truck (‘93) with 150,000 miles, and he > still has the origional rear brakes too. > Does this tell you something about GMC brakes. THE REARS DON’T WORK! > He has had his to the shop a few times asking about them, and he gets > the same dumb answers… "there’s nothing wrong with your brakes" > Anyone else have this problem?

Myself, no. I don’t have any of them newfangled trucks. Mine are all 70’s era disc/drum. OTOH, I gather that later model trucks, particularly Burbs, had very similar troubles, due to either or both of rapidly-wearing front pads, and/or a crappy proportioning valve. For some years (newer, though, I think) there’s a TSB about using the mondo heavy duty front pads and a new p-valve. If yours has some variety of ABS, I’d be suspicious of it, or the p-valve, preventing much pressure from going to the rears. Also note that, assuming you mostly brake whilst going forward and not in reverse, the front brakes tend to wear more anyway. (Though 100K miles is likely farther than they should go if they’re being used — A — http://www.slosh.com http://www.blazerchalet.com

Response:

are the self-adjusters working ?

– Hide quoted text — Show quoted text -> I’ve got a ‘92 Sierra. I have 91,000 miles and I’m still on the > origional rear brakes. I Keep checking them, and they still have a > ton of pad left. I changed the fronts at 60,000. > a friend at work has the same truck (‘93) with 150,000 miles, and he > still has the origional rear brakes too. > Does this tell you something about GMC brakes. THE REARS DON’T WORK! > He has had his to the shop a few times asking about them, and he gets > the same dumb answers… "there’s nothing wrong with your brakes" > Anyone else have this problem?

Response:

> are the self-adjusters working ?

ALL? I’d use a dial-micrometer to measure the width now and then after another 3k to verify that they’re actually working <g> Doc – Hide quoted text — Show quoted text -> I’ve got a ‘92 Sierra. I have 91,000 miles and I’m still on the > origional rear brakes. I Keep checking them, and they still have a > ton of pad left. I changed the fronts at 60,000. > a friend at work has the same truck (‘93) with 150,000 miles, and he > still has the origional rear brakes too. > Does this tell you something about GMC brakes. THE REARS DON’T WORK! > He has had his to the shop a few times asking about them, and he gets > the same dumb answers… "there’s nothing wrong with your brakes" > Anyone else have this problem?

Response:

The self adjusters require some effort to adjust; many of us do not back up our vehicles hard enough to activate the self adjusting mechanism. I used to do my Suburban on a regular basis, not necessary now that my teenagers drive it. They back up faster and hit the brakes harder than my wife and I do. True story. In quiet spot, back up a little quickly, then hit the brakes hard. Pull forward, hit the brakes to center the shoes, then repeat the backward portion one more time; the adjusters will only go one tooth on the star wheel per activation. Check your parking brake before and after, you should have more parking brake if the adjustment is tighter (less travel of the parking brake cable to activate the brake shoes). I started using this technique with 1984 Chevy 24′ motorhome chassis, still use it on my 97 Chevy 2500 HD. – Hide quoted text — Show quoted text – > are the self-adjusters working ? > I’ve got a ‘92 Sierra. I have 91,000 miles and I’m still on the > origional rear brakes. I Keep checking them, and they still have a > ton of pad left. I changed the fronts at 60,000. > a friend at work has the same truck (‘93) with 150,000 miles, and he > still has the origional rear brakes too. > Does this tell you something about GMC brakes. THE REARS DON’T WORK! > He has had his to the shop a few times asking about them, and he gets > the same dumb answers… "there’s nothing wrong with your brakes" > Anyone else have this problem?

Response:

I have 136,000 miles on my current ‘95 Chevy pick-up. I replaced the original front pads at 122,000 miles, and the original back shoes still have over 50% usable pad left on them. Do I think there’s anything wrong with them? – No, the truck stops fine and within specs. How can I be sure the rears are working? – When I had the fronts replaced I also had the rears cleaned and adjusted, and there was plenty of accumulated brake dust in the drum telling me that the rears were doing their job. I’ll be the first to admit I don’t carry much if anything in the bed all the time so I suspect the rears don’t do much work, but I’m sure they are doing their fair share. It’s been a very long time since I’ve activated the ABS so I don’t believe that is part of the issue. I honestly wish that all the brakes on the vehicles I have owned over the years would have given me the same service as the brakes on my current Chevy. Cheers – Jonathan — Acta Non Verba – Deeds Not Words Lieutenant Jonathan Race, EMS Supervisor Orange County (FL) Fire-Rescue Department

Response:

- Hide quoted text — Show quoted text – > are the self-adjusters working ? > I’ve got a ‘92 Sierra. I have 91,000 miles and I’m still on the > origional rear brakes. I Keep checking them, and they still have a > ton of pad left. I changed the fronts at 60,000. > a friend at work has the same truck (‘93) with 150,000 miles, and he > still has the origional rear brakes too. > Does this tell you something about GMC brakes. THE REARS DON’T WORK! > He has had his to the shop a few times asking about them, and he gets > the same dumb answers… "there’s nothing wrong with your brakes" > Anyone else have this problem?

I have a 1990 1/2 P.U. Auto 2wd. and i have gone over 100,000 K’s on the rears that where installed by GM 5 yrs ago. I am about to replace my 3 set of fronts. I don’t personal think there is any problem with that ratio. I am guessing that your front brakes handle about 75% of your braking!!

Response:

"Dave" wrote > I’ve got a ‘92 Sierra. I have 91,000 miles and I’m still on the > origional rear brakes. I Keep checking them, and they still have a > ton of pad left. I changed the fronts at 60,000. > a friend at work has the same truck (‘93) with 150,000 miles, and he > still has the origional rear brakes too. > Does this tell you something about GMC brakes. THE REARS DON’T WORK! > He has had his to the shop a few times asking about them, and he gets > the same dumb answers… "there’s nothing wrong with your brakes" > Anyone else have this problem?

Yeah, most GM owners of trucks from that era. And your friend is not getting a dumb answer…there is nothing wrong with your rear brakes "as they were designed by GM". Now, I will agree with you that there is something wrong with GM brakes…has been for some years now. It’s pretty sad when you see vehicles going through 5 sets of front brakes and the rears are hardly worn at all…..as you have noticed. The TSB mentioned by others addresses some of the problem, but it’s mostly for Suburban style vehicles. The new style trucks are much better. Other then some problems with clearance between the rear wheels and rear brake calipers…..I’m seeing some trucks with 150,000 kilometres on them and the front brakes still have over 50% left. Ian

Response:

Hey Doc..I have 150K on my rear brakes and they don’t seem to wear either. 92 S10. I noticed they don’t have the opening on the drum to manually adjust them like the older models did. I assume I’ve waited too long to change them and now my drums are grooved. What’s the trick on getting the drum off now? Lannie

– Hide quoted text — Show quoted text -> are the self-adjusters working ? at > ALL? I’d use a dial-micrometer to measure the width now and then after > another 3k to verify that they’re actually working <g> > Doc > > I’ve got a ‘92 Sierra. I have 91,000 miles and I’m still on the > > origional rear brakes. I Keep checking them, and they still have a > > ton of pad left. I changed the fronts at 60,000. > > a friend at work has the same truck (‘93) with 150,000 miles, and he > > still has the origional rear brakes too. > > Does this tell you something about GMC brakes. THE REARS DON’T WORK! > > He has had his to the shop a few times asking about them, and he gets > > the same dumb answers… "there’s nothing wrong with your brakes" > > Anyone else have this problem?

Response:

> Hey Doc..I have 150K on my rear brakes and they don’t seem to wear either. > 92 S10. I noticed they don’t have the opening on the drum to manually > adjust them like the older models did. > I assume I’ve waited too long to change them and now my drums are grooved. > What’s the trick on getting the drum off now? > Lannie

Lannie, There are three methods I use to get grooved drums off depending on how badly stuck they are. One is brute strength, one is brute force <g> and the other is more of a finesse approach. 1) Brute Strength. Using a meaty cold chisel <or other long, heavy object> as a pry bar, work your way around the drum, sticking the pry between the drum and backing plate. If yer’ lucky it’ll eventually "pop" and you’ll be able to get it off. This method requires new hardware <springs, clips, etc> to be installed as they’ll get wrecked as you’re prying it off. I always replace the hardware with the shoes anyways as it’s cheap insurance. 2) Brute force. Using a 3-arm jaw-style puller, have it at and it WILL come off. Put the ends of the puller arms in the space between the drum and backing plate, the center puller spindle on the rear-wheel hub, and just tighten the puller bolt until it pops off. This will also wreck the hardware. 3) Finesse. Although your backing plates don’t have an opening for the self-adjusters, there <should> be a few spots with punch-outs. Knocking out the punch-out<s> will give you access to the self adjuster release clip and star wheel where you can back the shoes way off until the drum literally slides off. Good luck picking the right punch out on the first try! <g> Rubber plugs for the holes are available at most autoparts stores. If I’m working on one of my trucks, I use methods 1 or 2, when working on someone elses’ vehicle I use the finesse approach. Hope this helps, Doc P.S. A few good whacks with a 3-5 lb sledge prior to attempting methods 1 or 2 will sometimes free the shoes up enough to make yer’ life a little more pleasant.

Response:

With the mileage I have on this thing, I think replacing everything at this point is a good idea anyway. I’ll start with step 1.

– Hide quoted text — Show quoted text -> Hey Doc..I have 150K on my rear brakes and they don’t seem to wear either. > 92 S10. I noticed they don’t have the opening on the drum to manually > adjust them like the older models did. > I assume I’ve waited too long to change them and now my drums are grooved. > What’s the trick on getting the drum off now? > Lannie > Lannie, > There are three methods I use to get grooved drums off depending on how > badly stuck they are. One is brute strength, one is brute force <g> and the > other is more of a finesse approach. > 1) Brute Strength. Using a meaty cold chisel <or other long, heavy object> > as a pry bar, work your way around the drum, sticking the pry between the > drum and backing plate. If yer’ lucky it’ll eventually "pop" and you’ll be > able to get it off. This method requires new hardware <springs, clips, etc> > to be installed as they’ll get wrecked as you’re prying it off. I always > replace the hardware with the shoes anyways as it’s cheap insurance. > 2) Brute force. Using a 3-arm jaw-style puller, have it at and it WILL > come off. Put the ends of the puller arms in the space between the drum and > backing plate, the center puller spindle on the rear-wheel hub, and just > tighten the puller bolt until it pops off. This will also wreck the > hardware. > 3) Finesse. Although your backing plates don’t have an opening for the > self-adjusters, there <should> be a few spots with punch-outs. Knocking out > the punch-out<s> will give you access to the self adjuster release clip and > star wheel where you can back the shoes way off until the drum literally > slides off. Good luck picking the right punch out on the first try! <g> > Rubber plugs for the holes are available at most autoparts stores. > If I’m working on one of my trucks, I use methods 1 or 2, when working on > someone elses’ vehicle I use the finesse approach. > Hope this helps, > Doc > P.S. A few good whacks with a 3-5 lb sledge prior to attempting methods 1 > or 2 will sometimes free the shoes up enough to make yer’ life a little more > pleasant.

Response:

>I have 150K on my rear brakes and they don’t seem to wear either. >92 S10. I noticed they don’t have the opening on the drum to manually >adjust them like the older models did. >I assume I’ve waited too long to change them and now my drums are grooved. >What’s the trick on getting the drum off now?

I would cut the back of the hold down pins off, and then pull.

Response:

Just curious, how does one go about cutting the back of hold-down pins off with the drum in place and no openings on the drum or the backing plate? Regards, Doc

Response:

Jack up the rear, start the truck, Push on pedal while looking at rear

Response:

I use a pair of diagonal cutters, The pins go in the back of the plate and through the shoes, look like a nail head. You should always be able to see them.

Response:

I have a 92 sierra also and i just passed 160,000. At 150,000 I took both assemblies appart to check cause I needed new brakes and found that one of my drums had rust on the inside from the shoes not touching at all. After cleaning all the moving parts and adding a new pair of shoes I can slide on the ice quite nicely now.

– Hide quoted text — Show quoted text -> "Dave" wrote > I’ve got a ‘92 Sierra. I have 91,000 miles and I’m still on the > origional rear brakes. I Keep checking them, and they still have a > ton of pad left. I changed the fronts at 60,000. > a friend at work has the same truck (‘93) with 150,000 miles, and he > still has the origional rear brakes too. > Does this tell you something about GMC brakes. THE REARS DON’T WORK! > He has had his to the shop a few times asking about them, and he gets > the same dumb answers… "there’s nothing wrong with your brakes" > Anyone else have this problem? > Yeah, most GM owners of trucks from that era. And your > friend is not getting a dumb answer…there is nothing wrong > with your rear brakes "as they were designed by GM". > Now, I will agree with you that there is something wrong > with GM brakes…has been for some years now. It’s pretty > sad when you see vehicles going through 5 sets of front > brakes and the rears are hardly worn at all…..as you have > noticed. The TSB mentioned by others addresses some > of the problem, but it’s mostly for Suburban style vehicles. > The new style trucks are much better. Other then some > problems with clearance between the rear wheels and > rear brake calipers…..I’m seeing some trucks with 150,000 > kilometres on them and the front brakes still have over > 50% left. > Ian

Response:

Front brakes tend to lock early in the wet causing ABS to activate (dangerous in heavy traffic bin there and done that) I replaced the rear shoes on our Suburban after My wife tagged someone due to above condition. I went to a brake "reliner" and have much better overall brake balance since with less tendency for the front brakes to lock and ABS to activate. The 2nd set of front pads are close to worn out in 4.5 years and 60,000 km ,granted truck was used as momstaxi with high brake cycles/km. One should see longer life with lower brake cycle/ km though parts are cheap and wear is expected anyway. Rolf

Response:

must be nice for brakes to last that long…lol.. i have a 97 z71 truck has 70,000 miles on it and front pads have been replaced 4-5 times already and need a new set again. rears have never been touched.

– Hide quoted text — Show quoted text -> Front brakes tend to lock early in the wet causing ABS to activate > (dangerous in heavy traffic bin there and done that) > I replaced the rear shoes on our Suburban after My wife tagged someone due > to above condition. > I went to a brake "reliner" and have much better overall brake balance since > with less tendency for the front brakes to lock and ABS to activate. > The 2nd set of front pads are close to worn out in 4.5 years and 60,000 km > ,granted truck was used as momstaxi with high brake cycles/km. > One should see longer life with lower brake cycle/ km though parts are cheap > and wear is expected anyway. > Rolf > "Dave" wrote > > I’ve got a ‘92 Sierra. I have 91,000 miles and I’m still on the > > origional rear brakes. I Keep checking them, and they still have a > > ton of pad left. I changed the fronts at 60,000. > > a friend at work has the same truck (‘93) with 150,000 miles, and he > > still has the origional rear brakes too. > > Does this tell you something about GMC brakes. THE REARS DON’T WORK! > > He has had his to the shop a few times asking about them, and he gets > > the same dumb answers… "there’s nothing wrong with your brakes" > > Anyone else have this problem? > Yeah, most GM owners of trucks from that era. And your > friend is not getting a dumb answer…there is nothing wrong > with your rear brakes "as they were designed by GM". > Now, I will agree with you that there is something wrong > with GM brakes…has been for some years now. It’s pretty > sad when you see vehicles going through 5 sets of front > brakes and the rears are hardly worn at all…..as you have > noticed. The TSB mentioned by others addresses some > of the problem, but it’s mostly for Suburban style vehicles. > The new style trucks are much better. Other then some > problems with clearance between the rear wheels and > rear brake calipers…..I’m seeing some trucks with 150,000 > kilometres on them and the front brakes still have over > 50% left. > Ian

Response:

thats 60000 km or aprox. 37500 mi.

– Hide quoted text — Show quoted text -> must be nice for brakes to last that long…lol.. i have a 97 z71 truck has > 70,000 miles on it and front pads have been replaced 4-5 times already and > need a new set again. rears have never been touched. > Front brakes tend to lock early in the wet causing ABS to activate > (dangerous in heavy traffic bin there and done that) > I replaced the rear shoes on our Suburban after My wife tagged someone due > to above condition. > I went to a brake "reliner" and have much better overall brake balance > since > with less tendency for the front brakes to lock and ABS to activate. > The 2nd set of front pads are close to worn out in 4.5 years and 60,000 km > ,granted truck was used as momstaxi with high brake cycles/km. > One should see longer life with lower brake cycle/ km though parts are > cheap > and wear is expected anyway. > Rolf > > "Dave" wrote > > > I’ve got a ‘92 Sierra. I have 91,000 miles and I’m still on the > > > origional rear brakes. I Keep checking them, and they still have a > > > ton of pad left. I changed the fronts at 60,000. > > > a friend at work has the same truck (‘93) with 150,000 miles, and he > > > still has the origional rear brakes too. > > > Does this tell you something about GMC brakes. THE REARS DON’T WORK! > > > He has had his to the shop a few times asking about them, and he gets > > > the same dumb answers… "there’s nothing wrong with your brakes" > > > Anyone else have this problem? > > Yeah, most GM owners of trucks from that era. And your > > friend is not getting a dumb answer…there is nothing wrong > > with your rear brakes "as they were designed by GM". > > Now, I will agree with you that there is something wrong > > with GM brakes…has been for some years now. It’s pretty > > sad when you see vehicles going through 5 sets of front > > brakes and the rears are hardly worn at all…..as you have > > noticed. The TSB mentioned by others addresses some > > of the problem, but it’s mostly for Suburban style vehicles. > > The new style trucks are much better. Other then some > > problems with clearance between the rear wheels and > > rear brake calipers…..I’m seeing some trucks with 150,000 > > kilometres on them and the front brakes still have over > > 50% left. > > Ian

Response:

gm truck self adjusters in the rear drums are not good. even if you use the parking brake regulararly, it does not self adjust well.. you can manually do it [take tire, drum off and roll the star wheel] which works best, or get some speed driving backwards and tromp on the brakes good and hard, this will also adjust the brakes too, but not as well — nick leinonen markham, ontario, canada http://community.webshots.com/user/nickleinonen .