Mechanics

MODELS PERSISTENT SQUEAK FROM DRIVER'S SIDE

1999 Jeep Other

Brakes problem
1999 Other Jeep Models 6 cyl Four Wheel Drive Automatic 117000 miles

Hi folks.

I have had an issue with my Jeep Grand Cherokee LAredo for a while now, and think I may have zoned in on the issue.

I have a squaeaking noise coming from my driver's side rear wheel. The noise goes along with the truck moving, so as the weel's speed increases, so does the frequency of the noise.

The noise goes away the moment you apply the brakes, hence why I don't believe it is, say, a bearing issue.

I was thinking perhaps it is a stuck caliper, but not sure exactly at this point as I have yet to inspect and my jack just broke!

Thanks for any feedback.
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Swataz
August 30, 2010.



Hi swataz. Welcome to the forum. Do you know for sure that you have rear disc brakes? If so, the rotors will likely not be the vented design since they don't get very hot. A warped rotor may not be felt in the brake pedal but it will cause the caliper to slide back and forth on its mount as the wheel rotates. Machining the rotor will solve that problem, and the mounts should be lubed with high-temperature brake grease. If allowed to continue, the sliding caliper will wear notches in the mount that can impede its free movement in the future.

If you have drum brakes, an egg-shaped drum will cause the released shoes to move back and forth on the backing plate which can lead to a squeak. Again, machining the drum, and placing a light film of brake grease on the six " lands" or raised spots on the backing plate that the shoes rest on will solve that squeak.

Also look for the ball of metal on the end of the parking brake cable hitting the inside of the drum. That can cause a shiny spot that you can see where it was hitting. Check that both shoes, (drum brake, or parking brake shoes inside the rotor), are touching the anchor post on top of the backing plate. If one is held away, suspect a parking brake cable stuck partially applied.

If you do have disc brakes on the rear, jack up all four wheels off the ground, then run it in gear with the left rear wheel removed. If you can see the caliper moving sideways, the rotor is warped and must be machined. If you do not see any movement, you can use an inexpensive dial indicator placed against the spinning rotor to measure the amount of warpage. A few thousandths of an inch will not cause a squeak. It will be much more significant if the rotor is the problem.

Caradiodoc

Caradiodoc
Aug 30, 2010.
Wow, thanks! That was quick and very thorough!

I will definitely do as much investigating as my limited toolset will allow. I'd love to get it on a lift but even my jack somehow lost the pin that tightens and releases the hydraulics, so I have to get this to a friend's house.

I do have disc brakes on the rear, yes. So, assuming I am reading what you said correctly, the likelihood is more so that it may be either an out of round rotor or a partially stuck emergency brake at this point?

Thanks again for your response. Awesome job.

Tiny
Swataz
Aug 30, 2010.
My vote is for the rotor, but just to not overlook something stupid, use a torque wrench to double-check the lug nuts. A loose wheel can cause a squeaking noise but usually it will be a lot worse than that.

If you can't actually see the caliper moving sideways as the wheel rotates, and if you don't have a dial indicator, consider switching the rotors from side to side to see if the squeak stops or goes to the other side.

Caradiodoc
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Caradiodoc
Aug 30, 2010.
Thanks. I will check out the lug nuts but I am pretty certain they are snug. Sadly, the noise was present well before and now, after I jacked it up 2 weeks ago to see if I could determine anything by eyeballing the rotor and caliper assembly.

I am thinking that if it was a true " seized caliper" issue, I would be dealing with more than just a squeaky noise at this point. Probably superheated rotors and some kind of smell too I would imagine!

I'll give the rotors my primary scrutiny.

Thanks again, caradiodoc.

Tiny
Swataz
Aug 30, 2010.

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