Popping Noise At Slow Speed With Brake Applied

Gageraid · **Posted:** Sat Jun 21, 2014 11:50 am

Haven't heard it in about 2 weeks. I am always listening for it, though. I'm really hoping it was just something stuck and it worked itself loose. That would be best case scenario.
Luckily, there have been no physical signs of damage and it hasn't effected braking performance, not that I ever use my brakes anyways. :goink:

I'm gonna give her a bath this week and I'll be sure to wash the undercarriage and brakes well.

Gageraid · **Posted:** Mon Jun 30, 2014 9:55 am

Well the sound is still there. Now I'm almost positive it's only coming from the passenger side.
Maybe a boot is torn? Not sure if that would make the noise.

mawlkrawler · **Posted:** Mon Jun 30, 2014 11:27 am

If the boot was torn I'd assume you'd hear it anytime you depress/release the brakes. Do you hear the noise only while applying them at low speeds? How much pad is left on both the interior/exterior pads? Any variance between the pads from the same wheel would indicate an issue with the caliper because they should wear evenly. Check the caliper boot to make sure its moving right and check the caliper pins to make sure they have plenty of silicone grease.

Sent from my iPhone 5

Gageraid · **Posted:** Mon Jun 30, 2014 12:05 pm

mawlkrawler wrote:

If the boot was torn I'd assume you'd hear it anytime you depress/release the brakes. Do you hear the noise only while applying them at low speeds? How much pad is left on both the interior/exterior pads? Any variance between the pads from the same wheel would indicate an issue with the caliper because they should wear evenly. Check the caliper boot to make sure its moving right and check the caliper pins to make sure they have plenty of silicone grease.

Sent from my iPhone 5

The noise is random, but it's only when I apply the brakes at low speeds. It doesn't happen every time.
I feel like it's more prone to happen when I've been coasting to a red light/stop sign then apply. It's definitely only happening in 1st and 2nd gear.
Like I've said, it's hard to duplicate, some days is worse than others.
When I checked the brakes last month they looked perfect to me.
Thanks for checking this thread...

Gageraid · **Posted:** Tue Jul 01, 2014 12:40 pm

Tightened the lower bolt on the passenger side sway bar end link. We'll see if that solves anything.

Gageraid · **Posted:** Sat Jul 05, 2014 9:50 am

Haven't heard anything since I tightened the bolt. I can't say for sure if it's solved yet since I haven't had to come to many complete stops/slow creeps since then.

JeepinJarhead03 · **Posted:** Sat Jul 05, 2014 9:33 pm

first time i had popping under the situations you've described on my KJ, was an ebrake shoe that has separated from the backing .. someone had drove down the highway with the e-brake up for a bit

second time , tho it was a different category of popping, part of my ps rack bushing decided to stay somewhere between IL and OH. - that ones easy to diagnose because itll do it while sitting still

Gageraid · **Posted:** Sat Jul 05, 2014 10:45 pm

JeepinJarhead03 wrote:

first time i had popping under the situations you've described on my KJ, was an ebrake shoe that has separated from the backing .. someone had drove down the highway with the e-brake up for a bit

second time , tho it was a different category of popping, part of my ps rack bushing decided to stay somewhere between IL and OH. - that ones easy to diagnose because itll do it while sitting still

Thanks for some input.
Anyways... Of course the sound is back. I was able to make it happen twice tonight. Both times were when going 2 mph with my foot as light as possible on the brakes. I don't understand this anymore. If I go say 60 mph and apply the same extremely minimal brake pressure there is no sound. :dizzy:

I think I found a good way to explain the type of sound it is. It reminds me of the clicking sound that a torque wrench makes.
Next time I get a chance I'll see if maybe I can bend the brake dust shield back slightly even though I've checked it a thousand times.

Gageraid · **Posted:** Sun Jul 06, 2014 6:59 pm

Bent the brake dust shield a little with no luck...
I could be wrong, but I feel like the noise is more likely to happen when the Jeep is on an incline along with the light braking at crawling speeds.

Gageraid · **Posted:** Tue Jul 08, 2014 9:25 am

Think I'm going to take it to Midas on Saturday to see if they can find anything wrong. I wonder if the calipers are loose or something.

dgeist · **Posted:** Tue Jul 08, 2014 4:04 pm

Could be a drive shaft. It would make sense that if it's a ball loose in the CV (or similar) that you'd only hear it at low speed (as centripetal acceleration sometimes keeps things from rattling while spinnning). The brake actuation might be a reg herring, basically putting back-pressure on the drive system and causing the joints to smack around against themselves internally.

Assuming you can take off the front drive shaft in a KK like you can in a KJ, why not try dropping that out and seeing if the noise goes away?

Dan

Gageraid · **Posted:** Wed Jul 09, 2014 9:20 am

dgeist wrote:

Could be a drive shaft. It would make sense that if it's a ball loose in the CV (or similar) that you'd only hear it at low speed (as centripetal acceleration sometimes keeps things from rattling while spinnning). The brake actuation might be a reg herring, basically putting back-pressure on the drive system and causing the joints to smack around against themselves internally.

Assuming you can take off the front drive shaft in a KK like you can in a KJ, why not try dropping that out and seeing if the noise goes away?

Dan

Trying to upload a picture, but it doesn't want to show up in my email.
I think the part is called the axle boot... that's where the noise is coming from.
When I took off the tire and rotated the hub by hand I get the noise from this area.
I placed my hand on the boot and I can even "feel" the noise. It sounds like ripping rubber, but no signs of anything.
If this picture uploads, I want to clarify that's what the part is called.

What is this boot called? The tire was off and the Jeep was raised so that's why the angle looks extreme.

dgeist · **Posted:** Wed Jul 09, 2014 1:54 pm

It's called the inner CV axle boot (the one to the outside by the wheel is accordingly the "outer CV axle boot"). If you can feel it right there, I'd suspect it's your joint that's the culprit. A bad seal or small crack can let water/debris in and lubrication out. Also, putting on a lift does put more strain on them as they're moving through a more extreme range. You might try jacking up that side from under the control arm (so the joint is almost straight) and see if the noise/feel changes. If it does, that's almost definitely the problem.

Dan

Gageraid · **Posted:** Wed Jul 09, 2014 10:36 pm

dgeist wrote:

It's called the inner CV axle boot (the one to the outside by the wheel is accordingly the "outer CV axle boot"). If you can feel it right there, I'd suspect it's your joint that's the culprit. A bad seal or small crack can let water/debris in and lubrication out. Also, putting on a lift does put more strain on them as they're moving through a more extreme range. You might try jacking up that side from under the control arm (so the joint is almost straight) and see if the noise/feel changes. If it does, that's almost definitely the problem.

Dan

So if it's the joint, what needs to be replaced?
I can't really do too much work on the Jeep where I live now. Hoping not to spend an arm and a leg on the fix.
I've looked VERY closely for any cracks in the boot, and I see nothing. I'm sure if it's cracked it's going to be microscopic. No signs of any grease leaking.
Friday morning I'll have time to look at it again.
Thanks for taking the time to reply to my issue.

dgeist · **Posted:** Thu Jul 10, 2014 9:22 am

Gageraid wrote:

So if it's the joint, what needs to be replaced?
I can't really do too much work on the Jeep where I live now. Hoping not to spend an arm and a leg on the fix.
I've looked VERY closely for any cracks in the boot, and I see nothing. I'm sure if it's cracked it's going to be microscopic. No signs of any grease leaking.
Friday morning I'll have time to look at it again.
Thanks for taking the time to reply to my issue.

So, first of all, if it's on the passenger side (not sure from the photo), there's also a shaft that goes from the differential over to the inner suspension arm mount and the CV axle actually attaches to it. That short drive section has a bearing that it rides in right where the CV attaches.

If you want to diagnose it yourself, you're going to have to isolate things to see if the sound goes away. The CV axles aren't too hard to remove, but doing so requires some specific tools (like a large socket to remove the nut at the hub assembly, etc.). You could take a suspected CV axle out and the remaining one (and the driveshaft to the t-case) would spin freely, although probably not in such a way that would prevent that short axle section from spinning too. If you want to isolate THAT part while the vehicle is rolling, you'll need to take out BOTH CV axles and drive it a bit. Really trial and error and elimination of possibilities is about the only way to narrow things down unless you know exactly what the problem is. The alternative is throwing money at the problem and replacing things you THINK might be causing your issue, and unfortunately that's how a lot of shops operate, because they want to get you in and out and don't mind passing on the cost of parts that you may not have needed to replace.

If you don't have the time/tools to do this kind of thing yourself, you may consider talking with a driveline shop near you. They specialize in things like axles, differentials, CVs, etc. and often have the ability to troubleshoot those things much more effectively (and possibly faster and cheaper) than a regular service shop. At the very least, any decent business will listen to your symptoms and be able to at least estimate troubleshooting/repair based on what the problem turns out to be.

Dan

Gageraid · **Posted:** Thu Jul 10, 2014 10:45 pm

I didn't know there were specific driveline shops. Wonder if one is located anywhere near me.
*EDIT That's the passenger side in the photo.

dgeist · **Posted:** Fri Jul 11, 2014 6:39 am

Gageraid wrote:

I didn't know there were specific driveline shops. Wonder if one is located anywhere near me.
*EDIT That's the passenger side in the photo.

Don't know what part of jersey you're in, but google maps over your local city and the word "driveline" should tell you.

Gageraid · **Posted:** Fri Jul 11, 2014 10:02 am

I'm in the Central part of Jersey. Did a quick Google search last night and found a few shops.
Going outside right now to see if I can get a video of this sound real real quick.

Gageraid · **Posted:** Fri Jul 11, 2014 10:48 am

The ripping noise is what is really loud to me. The video captures it well. It's louder when I brake under the conditions I've previously described.

http://youtu.be/jcISVQcQYT4

dgeist · **Posted:** Fri Jul 11, 2014 4:44 pm

Sounds like something with bearings in it that should be greased have a distinct LACK of being greased...

Popping Noise At Slow Speed With Brake Applied

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