Rear Wheel Scraping Sound -- Brake Problem?

[dukbludvl]

My 2000 GMC Yukon 2wd with P265/70 R16 Michelin LTX/MS has 78,000 miles on it.

 

I recently noticed that the driver's rear wheel is producing a repetitive scraping sound. It can best be heard between 15-35 mph with the windows open (it finally got warm enough here in NC to open the windows). The faster I drive, the faster the repetition of the sound, and it is more pronounced on right-hand turns (no sound on left-hand turns, I don't think). It also does it when I'm going straight, but it's not as loud, and it does it when I brake, too.

 

I'm a novice mechanic and have fixed everything on this truck myself so far (with all of your help)... my initial thought is that it's something with the brakes... it definitely sounds like metal on metal, it's not screechy or high-pitched, but it is a definite scraping sound.

 

Can you guys help me try to figure out what it might be?

 

I did have my tires rotated 2 weeks ago, and I noticed it shortly after that. But, it may have been doing it for a while and I just couldn't hear it because the windows were closed. I'd say it has gotten noticeably worse over the course of the past few days, though, which makes me think it started recently. I hope the shop that does my rotations didn't mess something up. All seemed to be well before that.

 

Please help! Could it be time for new rear brakes? I had a good 33% pad left at the last tire rotation about 7,500 miles ago, according to the shop. I forgot to ask about them this last time, though.

 

Thanks guys, I really appreciate it.

[Bish]

Couple thoughts. First it could be the ebrake shoe. If the clip failed (like most do), it will allow the shoe to move and contact the drum (inside the rear rotor). $50 for a kit with updated clip and shoes and you could do it yourself.

 

I also had a similar but worse sound after 4 years Turned out to be the brake backing plates. Mine rusted so bad that they bubbled and expanded enough to contact the rotor under certain conditions. I initially bent the backing plate to pull it a little further away from the rotor but it came back. I finally replaced the backing plates and it went away. They must be the cheapest metal possible as mine were disintegrating after 4 years. If you live where they use salt, they rust very quickly.

 

Replacing the backing plates requires you to pull the axle. I ended up replacing the axle seals also (130K on my Tahoe) while I was in there. A little tricky at first but once I did one side, the other was cake

[Shawn T]

It sounds like they bent your dust cover when they rotated your tires. They are very thin and bend easily. I would remove your tire and check to see if it is rubbing against the rotor. I have had the exact same thing happen to me twice. It is also possible they over-torqued the lug nuts and warped the rotor. Highly unlikely though, they usually finish up with a torque wrench. It is also possible they droped a nut or something, and it is lodged between the dust cover and the rotor. Always try the simplest solutions first. If none of these are the problem, then start trouble shooting the brakes.

[dukbludvl]

what does the dust cover look like and where is it located? I've never done a brake job (although I probably need to do mine soon)...

 

Thanks for the tips guys. I'll check the possibility that it was something minor from the rotation, then I'll look at whether it is the ebrake clip. What does the ebrake clip look like? Does anyone have diagrams of this stuff? Does anyone know the part number for the ebrake clip kit that is $50?

 

I'd REALLY prefer not to have to take it to the dealer. So far, I've done all the repairs myself -- I'd rather not shell out the money and I want to make sure it's done right.

 

Thanks guys!

[Shawn T]

what does the dust cover look like and where is it located?  I've never done a brake job (although I probably need to do mine soon)...

 

Thanks for the tips guys.  I'll check the possibility that it was something minor from the rotation, then I'll look at whether it is the ebrake clip.  What does the ebrake clip look like?  Does anyone have diagrams of this stuff?  Does anyone know the part number for the ebrake clip kit that is $50?

 

I'd REALLY prefer not to have to take it to the dealer.  So far, I've done all the repairs myself -- I'd rather not shell out the money and I want to make sure it's done right.

 

Thanks guys!

 

<{POST_SNAPBACK}>

 

 

 

dukbludvl

Like Bish said check the ebrake. It is called a "hat brake". It just looks like a little anvil that makes contact against the rotor. The clip is what holds it away from the rotor. If this clip brakes or falls off the hat will drag against the rotor.

The dust cover is located directly behind the rotor mounted to the axle housing. It usually is only about a half of an inch away from the rotor. They are very thin and can bend easily. Just inspect it to see if there is any damage or if it is making contact with the rotor. It would be easier to block the front tires, put the tranny in neutral and jack the rear end up. Just make sure it is not going anywhere. That way you can remove the the tire and spin the axle and see where the contact is being made. Better yet, put it on a hoist. I would have the place that rotated it put it on their hoist. Make sure you are there to listen in with them. Technically it started when they rotated their tires.

[gnutruk]

There is a TSB out on that parking brake issue, if that's your problem. There may be an updated bulletin, but here's the most recent one I have.

 

gnutruk

 

 

 

Parking Brake TSB

 

 

Brakes - Scraping Noises From Rear of Vehicle

 

File In Section: 05 - Brakes

 

Bulletin No.: 02-05-26-002A

 

Date: February, 2003

 

TECHNICAL

 

Subject:

Scraping Noise From Rear Of Vehicle

(Replace Parking Brake Shoe Kit and Clean Drum In Hat Rotor)

 

Models:

2002-2003 Cadillac Escalade, Escalade EXT

1999-2003 Chevrolet Silverado 1500 Series Pickups

2000-2003 Chevrolet Suburban, Tahoe 1500 Series Models

2002-2003 Chevrolet Avalanche 1500 Series Models

1999-2003 GMC Sierra 1500 Series Pickups

2000-2003 GMC Yukon, Yukon XL 1500 Series Models

 

This bulletin is being revised to add Suburban and Yukon XL models. Please discard Corporate Bulletin Number 02-05-26-002 (Section 05 - Brakes).

 

Condition

 

Some customers may comment on a scraping noise from the rear of the vehicle while driving. The noise may be intermittent.

 

Cause

 

Condition may due to the parking brake shoe contacting the drum in hat rotor without the parking brake being applied, causing premature wear on the shoe lining.

 

Correction

 

Replace the parking brake shoe and install a new designed spring clip retainer. Follow the service procedure below to correct this condition.

 

1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in the General Information sub-section of the Service Information (SI Document ID # 639546).

 

2. Remove the tire and the wheel. Refer to Tire and Wheel Removal and Installation in the Tires and Wheels sub-section of the Service Information (SI Document ID # 656965).

 

3. Relieve the tension on the park brake cables by loosening the nut at the equalizer.

 

4. Mark the relationship of the rotor to the hub.

 

5. Remove the brake caliper bracket mounting bolts.

 

Notice : Support the brake caliper with heavy mechanic's wire, or equivalent, whenever it is separated from it's mount and the hydraulic flexible brake hose is still connected. Failure to support the caliper in this manner will cause the flexible brake hose to bear the weight of the caliper, which may cause damage to the brake hose and in turn may cause a brake fluid leak.

 

6. Remove the brake caliper and brake caliper bracket as an assembly and support with heavy mechanic's wire or equivalent. DO NOT disconnect the hydraulic brake flexible hose from the caliper.

 

7. Remove the rotor retaining push nuts from the wheel studs (if applicable).

 

Notice DO NOT use a hammer to remove the rotor from the hub; it may cause damage to the rotor.

 

Important :The rotor may not be easily removed from the hub due to a rust build up on the outside edge of the drum and hat portion of the rotor.

 

8. Remove the rotor from the hub. If the rotor cannot be removed from the hub by pulling on the rotor, use J 46277 rotor removal tool.

 

Notice :Place J 46277 between the rotor surfaces in the vent section of the rotor. DO NOT place J 46277 on the back side of the rotor surface, it may damage the rotor surface.

 

9. Using removal tool J 46277 on slide hammer J 6125B, remove the rotor by placing removal tool J 46277 in the vent section of the rotor at the twelve, three, six and nine o'clock positions, not necessarily in that order.

 

10. Clean the rust ridge from the drum portion of the rotor using a grinding stone and rotor resurfacing kit J 41013.

 

11. Remove the spring clip bolt (3) and retainer (2) and discard.

 

Important :Minimum thickness of the parking brake shoe lining in any given spot is 1.5 mm (0.06 in).

 

12. Measure the parking brake shoe thickness in multiple spots. Replace the parking brake shoe if the thickness is less than 1.5 mm (0.06 in). Continue with Step 14.

 

13. If the parking brake shoe lining is greater than 1.5 mm (0.06 in), continue with Step 19.

 

14. Rotate the parking brake shoe (1) out from the bottom and pull it out of the adjuster. Discard the shoe.

 

15. Remove the park brake shoe assembly from the vehicle by placing one of the open ends of the shoe over the axle flange and rotate the shoe until it has cleared the flange.

 

16. Turn the adjustment screw (1) to the fully home position in the notched adjustment nut.

 

17. Install the new park brake shoe assembly (1) from the parking brake shoe kit, P/N 88982875, to the vehicle by placing one of the open ends of the shoe over the axle flange and rotating the shoe until it is behind the flange.

 

18. Slide the shoe into the adjuster and position the shoe to the backing plate. Install the retaining spring clip (2) and bolt (3) from the parking brake shoe kit, P/N 88982875. If using parking brake service kit 88982875, SKIP Step 19.

 

19. Replace the retaining spring clip (2) and bolt (3) from the parking brake retaining spring clip kit, P/N 88982879.

 

Tighten

Tighten the bolt (3) to 5 N.m (44 lb in).

 

20. Set the J 21177-A so that it contacts the inside diameter of the rotor.

 

21. Position the J 21177-A over the shoe and the lining at the widest point.

 

Important :

 

^ The parking brake adjustment screw threads should not exceed 5 mm (0.2 in) of exposed thread.

 

^ The clearance between the park brake shoe and the rotor is 0.6604 mm (0.026 in).

 

22. The parking brake adjustment screw threads should not exceed 5 mm (0.2 inch) of exposed thread.

 

Notice : Whenever the brake rotor has been separated from the wheel bearing flange, clean any rust or foreign material from the mating surface of the rotor and flange with the J 42450 hub cleaning kit. Failure to do this may result in increased lateral runout of the rotor and brake pulsation.

 

23. Use the J 42450-A to clean all rust and contaminants from the mating surface of the hub flange.

 

24. Use the J 41013 to clean all rust and contaminants from the inside diameter of the hat section of the brake rotor to prevent any foreign material from getting between the brake rotor and the hub flange.

 

25. Align the mark on the rotor with the mark on the hub and install the rotor by slowly turning the rotor while pushing the rotor towards the axle.

 

26. Install the caliper and the bracket as an assembly to the vehicle.

 

27. Perform the following procedure before installing the caliper bracket mounting bolts.

 

^ Remove all traces of the original adhesive.

 

^ Clean the threads of the bolt with brake parts cleaner, P/N 12346139 (Canadian P/N 10953463), and allow to dry.

 

^ Apply threadlocker, GM P/N 12345493 (Canadian P/N 10953488), or Red LOCTITE™ # 272, to the threads of the bolt.

 

Notice :Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

 

28. Install the caliper bracket mounting bolts.

 

Tighten

Tighten the brake caliper bracket mounting bolts to 175 N.m (129 lb ft).

 

29. Repeat this procedure on the other side of the vehicle.

 

30. Tighten the nut to the intermediate cable at the equalizer.

 

Tighten

Tighten the nut to 3.5 N.m (31 lb in).

 

31. Install the tire and wheel assembly. Refer to Tire and Wheel Removal and Installation in the Tires and Wheels sub-section of the Service Information (SI Document ID # 656965).

 

32. Lower the vehicle.

 

33. Verify that the self adjuster lock-out pin has been removed.

 

34. Fully apply and release the park brake pedal three times.

[Taaaaaaahoe?]

Without a dobut it is your e-brake making the noise, as stated in above TSB

 

Mike

[dukbludvl]

how difficult is it to do the job indicated in the TSB above? what are the tools it's referring to? i've never worked on brakes before. what parts does this TSB require? is it just the kit mentioned in the post above?

 

thanks.

[RyanbabZ71]

I had the same noise in my silverado last summer. Only about 40K at the time. I changed the rear brakes (pads and turned rotors) and the noise was gone.

[dukbludvl]

Hi Guys,

 

Just wanted to let y'all know how this ended up for me. I ended up taking the truck to my local dealer to get the fix done. They replaced both ebrake shoes and had to replace one of the rotors because it was torn up. That work plus checking my brakes was $411... normally, I would have tackled this job myself, but I just don't have the time and I'm going on a couple of 400+ mile trips in the next few weeks, so I had to get it done.

 

Thanks to all of you for your help and for pointing me in the right direction. As always, you guys diagnosed my problem.

 

Thanks!

 

Jon