My 1998 GMC 2500 has had a bad rear brake squeak since right after I got it a couple months ago. It wasn't doing it when I first got it and then a couple weeks later it started. I pulled the rear drums and it looks like the brakes were just done even the harware looked new inside there. So with the drums off I cleaned them real good and even took some 200 grit sandpaper and lightly sanded the shoes and drums. I put it back together and it was good for a couple days when it started again. I didn't have time to mess with it before my monthly trip to Atlanta and it never did it once on the trip with the trailer connected. It was fine for a couple days after I got back and now it has started again and sounds horrible. It has a real high pitch squeel under about 5 MPH and right before you come to a complete stop it sounds like a garbage truck stopping. My thoughts are either the brake shoes are just cheap POS or is it possible, since these are the rear drums that have the bearings and seals built in which gets lubed by the same lube that is in the rear end, that one or both of the seals is letting a tiny bit of lube by which is getting on the shoes. The brakes feel great and stop, even with a loaded trailer, fine. What do you guys think?

 

My driver side rear did that exact same thing! The drums and shoes were bad so I redid the rear brakes and it stopped for a few days. I took everything back apart and cleaned it all off with brake cleaner and realized that my wheel cylinder was leaking pretty bad. It had a nice little hole in the seal. I replaced that and all of the brake line up to the T and it CONTINUED to squeak even after sanding down and cleaning off the drums and shoes real good. I ended up talking to the guy at NAPA and he warrantied my drum and shoes for me and gave me new ones for free considering how the others only had 200 miles on them. It's been 4000 miles and haven't heard a thing out of them since!

BTW, Don't be dumb like me and put the middle cross-brace thing on backwards... It makes for awkward stopping

 

Thanks for the input I guess I am going to tear them back apart tomorrow and replace everything. I hate to becasue those drums are not cheap. Are yours the ones where you have to pull the axles to get the drums off?

 

If it was leaking gear oil into drums it would start grabbing ect. These wearever brake shoes auto parts sells , junk . They will wear your drums , and disc out before they wear out. Usually here at slow speeds. I would just change shoes.

 

Nope mine just slipped right off--with a hammer and board and persistence. I don't have the full floating. Mine has the 13" drums with 2.5" shoes.

If your drum is somewhat decent I'm sure you could get it turned. They're steel so the fluid shouldn't penetrate. The shoes... they're probably toast. Let me know how it turns out?

I'm curious, are these wheel cylinders notorious for going bad? My 92 had both the rear wheel cylinders go out.

PS. I was able to adjust up my rear brakes real tight so that it almost gets rid of the soft pedal feel that you usually get with the 96-98 pickups. Those 13" rear drums over the 1/2 ton size really grab good. i tried adjusting up a 97 1500 and it didn't hardly make much of a difference. But I believe it had 9 or 10"

 

I finally felt up to tearing back into my garbage truck sounding rear brakes today. I have determined it to be the wheel seals leaking and letting fluid get on the brake drums and shoes. I had a thin layer of rear end lub on the inside of the drums and the shoes are saturated. This explains why it was quiet when I first put it back together after cleaning everything. I guess the only way for the rear end fluid to get into the drum area is from the wheel seals correct or should I be checking something else??? Thanks!

 

Ooh it is rear axle fluid and not simply brake fluid from the Wheel cylinders?? In that case, I really don't know... Sorry I can't be of more help

 

Your correct Shamrock . You will have to replace the seals. Make sure you clean all good
any least bit of oil be grabbing again.

 

Well this job turned into a mission, but I got it done today. I was a little nervous because the first time I stopped it squeaked like it did before, but then it was fine. I guess there was a little that I didn't get off. I took it on a long test ride and it never made another sound. Thank God - It was driving me crazy!!!!!
I got conflicting info on the torque of the adjusting nut. One mechanic told me to just tighten it down to take all the slack out, and another told me it had to be torqued. I found a service manual and according to it I needed to torque it to 50 ft lbs and then back it off 1/4 turn. That seems to have done the job.

 

Glad you got it fixed. Never did understand , when they tell you to torque it to so and so then back off. Seems you would just torque to maybe 45 leave it.
AHH HECK. It works i guess.lol