Resonating Brake Noise '99 Suburban

[wilkerson3]

Our '99 Suburban has a brake noise that isn't really a grinding nor a squeaking, but more of an auditory/resonating sound - like a vibrating noise. The noise is coming from the front brakes. The noise can usually be recreated when brakes are applied and we are braking at a decline (front end taking most of the weight of the vehicle). It seams to be only the last few feet of a complete stop. The noise doesn't happen on every stop. If the noise occurs upon stopping and we push the accelerator no noise will be heard when accelerating. If the noise occurs upon stopping and we idle from the stopped position there will be a pulsating noise/vibration for maybe 5 or 6 revoluions. No vibration or steering wheel wobble like a warped rotor.

During the hot summer the noise only occurred on the first and sometimes second braking after it had been sitting over night. Then never again. As the weather gets cooler and more humidity in the air the problem is now more persistent and could occur anytime throughout the day. This morning I heard another Chevy Truck - maybe a '96 Silverado brake and the same noise occurred with his truck. Thought maybe this might be a common problem with these years of trucks.

Brake pads were replaced in Spring (noise happened in cooler weather with brand new pads) and pads are still good (on front and back). Greased calipers when replaced pads. Rear drums were just inspected - still have plenty of pad and also had a ton of rust dust. Blew out dust. 80% of pads were shiny from contact and 20% still rough.

Questions - could a cheaper rotor have been installed and be the problem - replace the rotors? Front brakes taking on too much work and rear brakes not helping - replace the drums?

Obviously looking for cheaper solution. Brakes stop vehicle just fine. The noise is really, really loud sometimes and quite embarrassing - so would rather get rid of it.

Thanks

[gmtech1]

Sounds like maybe you are have a low speed ABS activation. If so, you can try and clean the front wheel speed sensors, and inspect the grease in the hub assy when the sensor is out. If its rusty looking the hub needs replaced. There is a recall out for some of these and much info in this forum if you seach " low speed ABS activation" in the suburban forum.
In the end you will probably end up replacing the front hubs.

[j cAT]

If you have good braking then the ABS WOULD NOT BE THE PROBLEM.

BRAKE noise is usually from the pads being made of low quality material. also the back of the brake pads require a high temp anti seize compound to reduce and eliminate noises. your braking noise only at the slow speed is when this normally occurs. the pads/retaining clips also may have not been installed properly as well.

the rear drums with 80% of the shoe being worn may indicate they need adjusting not a new drum. drums wear at a rapid rate with the use of non ASBESTOS brake material.

with your vehicle the rear drums do a good amount of the braking effort.

do not blow out this dust material. use a spray bottle with some dish soap water mix in it. place newspaper on the ground under the axle to collect the dust then rap it up and in the trash. you do not need chemicals/degreasers to do this. these solvents are bad for you and the rubber seals.

brake dust is not good .

[mishalah]

Also make sure your caliper pins are lubed/greased. If they stick the pads will vibrate against the rotor, wear out unevenly, and chew up your rotors.

[wilkerson3]

Here is what happened:

1) Took Suburban to local repair shop. They offered to change the rotors, front and back pads and rear drums. I told them if there is no safety issue I would pass on their expensive offer. They adjusted/tightened the rear brakes because I was told they weren't helping the front brakes.
For next two days noise was happening on every braking stop and even LOUDER than before.

2) Took Suburban into Chevy dealership because I thought it might be a common problem. They were surprised at the noise and how loud it was. Of course, my luck, it wasn't a common problem. Long story short after 2 1/2 hours of hunting they readjusted rear brakes back to correct setting and knocked the glaze off the rear pads. Charged me $34 and the best part...

No noise. It was almost surreal to drive off the lot because I was so used to the slightest braking making the horrific noise.

So if you've got a noise coming from your brakes that isn't a grinding noise and isn't a squeaking noise ask if there is a glaze that could be knocked off. Thank you for your suggestions here. I asked Chevy to look at your different suggestions you guys made as I kept asking/bugging the repair guy.

Thanks again and have a great weekend.

[mishalah]

Kudos to the dealership. Please post their name so others around you can consider using them.

[gmtech1]

Glad to hear it was a cheap and easy fix for you! Thanks for posting!

[j cAT]

Originally Posted by wilkerson3

Here is what happened:

1) Took Suburban to local repair shop. They offered to change the rotors, front and back pads and rear drums. I told them if there is no safety issue I would pass on their expensive offer. They adjusted/tightened the rear brakes because I was told they weren't helping the front brakes.
For next two days noise was happening on every braking stop and even LOUDER than before.

2) Took Suburban into Chevy dealership because I thought it might be a common problem. They were surprised at the noise and how loud it was. Of course, my luck, it wasn't a common problem. Long story short after 2 1/2 hours of hunting they readjusted rear brakes back to correct setting and knocked the glaze off the rear pads. Charged me $34 and the best part...

No noise. It was almost surreal to drive off the lot because I was so used to the slightest braking making the horrific noise.

So if you've got a noise coming from your brakes that isn't a grinding noise and isn't a squeaking noise ask if there is a glaze that could be knocked off. Thank you for your suggestions here. I asked Chevy to look at your different suggestions you guys made as I kept asking/bugging the repair guy.

Thanks again and have a great weekend.

the reason the rear shoes are glazed is from the rear brakes dragging. this is from not properly adjusting the park brake cable when new shoes and pads are installed. this is a common screw up. the park brake cable must have some slack in it,

[wilkerson3]

j cAT - thanks, will remember the slack next time brakes are replaced

Dealership who fixed the brakes is Van Chevrolet in Kansas City (Northland)