Poping sound in rear brakes in '98?

I have been having a popping sound coming from the rear brakes lately. I have newer shoes and drums. It seems to come only from the left side, and dosen't happen all the time. The popping or thumping sound slows down as the vehicle comes to a stop. Any ideas? Do I need to bleed my brakes maybe?

Thanks guys.

Burley

Does newer mean recently replaced or was there a design change along the way? Anyway, I have a '93. It that's different from '98 then just consider this a FYI to everyone.

I recently went to change by rear shoes and found one of the springs (the one that spans across the adjuster, not one of the main springs) laying in the bottom of the drum, between the shoes happily wearing a deep, round, smooth groove in the drum. It would have eventually sliced the drum clean off.

Aside from brakes, the noise could be an axle bearing. It would be worth it to find the source ASAP.

XJ Dreamin'
'93XJ stock, 4.0l HO, AW4, open D-35c rear, LT235/75R15 A/T's

The noise only happens when the brakes are applied. Does that eliminate the bearings? I don't hear it when I use the emergency brake to stop, but then again there isn't as much brake applied that way.

XJ Dreamin' said:

Does newer mean recently replaced or was there a design change along the way? Anyway, I have a '93. It that's different from '98 then just consider this a FYI to everyone.

I recently went to change by rear shoes and found one of the springs (the one that spans across the adjuster, not one of the main springs) laying in the bottom of the drum, between the shoes happily wearing a deep, round, smooth groove in the drum. It would have eventually sliced the drum clean off.

Aside from brakes, the noise could be an axle bearing. It would be worth it to find the source ASAP.

XJ Dreamin'
'93XJ stock, 4.0l HO, AW4, open D-35c rear, LT235/75R15 A/T's

Click to expand...

Hey! I pulled my rear left this afternoon because it was making a grinding/squeaking noise (I had just changed the shoes last week). My 3yo son was standing beside me as I pulled the drum and the entire self adjusting system rained out on the driveway. I'm sitting there with the drum in my lap and my son is scrambling to pick up the pieces. "Daddy! Put these back in the bowl!" He was very concerned that I not scatter pieces of the Jeep on the ground. My point? You never can tell with brakes.

Seriously, I've been fooled by both axle bearing and U-joint. When they are going out they can sound different under braking because of different loads between accel, coast, and braking. But you're talking about a sound only when braking. Does the '98 have ABS? Could the popping be a symtom of problems with ABS? I know that my experiences over the last week (and years and years with MOPAR brake systems) tell me there could be anything in there. Come to think of it: I had the entire lining separate from a shoe once. It got lodged under the other shoe and locked the wheel up solid at 55 mph. It was hades getting that drum off.

I say open it up and take a look before something else falls off.

Good Luck,
XJ Dreamin'
'93XJ stock, 40l HO, AW4, open D-35c, LT235/75R15 A/t's

Did you recently remove the wheels? Try reseating the brake drums again. I've found that if you remove the rear wheels with the parking brake on, the brake drum will "cock" itself on the wheel studs with the parking brake on. It will then no longer seat evenly, and be skewed a bit. The brake drum sits rather loose on the wheel studs without the parking brake on.

Secure your vechicle so it doesn't roll, and make sure the parking brake isn't on. Jack up the rear, remove the wheel, pull and reseat the brake drum so that it's not hanging up or binding on anything, reinstall the wheel. I'd do both sides just to make sure.

This has always worked for me on my '98....

Ivan

There Is A Tbs For Rear Brake Drum Movement
On 8 1/4 Rear Ends
Seems The Axle Shafts Do Not Have Proper Drum Pilots
Which Cause A Thumping From Movement On The Shaft When Stopping
Tbs 05-05-00
Replace Axle Shafts With Up Dated
05018393aa
So Check If The Drum Seemd Loose On The Shafts

I have had the rear wheels off twice. Once to look and once to put new drums on (i thought maybe they were warped). When I put new pads on a few months ago i bought the cheapies. Could that be the cause? I also put on a new hardware kit.

How can I tell if the drum is too loose on the lugs? I have always thought that most drums weren't on tight on most vehicles. Maybe I am misunderstanding something.

Burley

Burley said:

I have had the rear wheels off twice. Once to look and once to put new drums on (i thought maybe they were warped). When I put new pads on a few months ago i bought the cheapies. Could that be the cause? I also put on a new hardware kit.

How can I tell if the drum is too loose on the lugs? I have always thought that most drums weren't on tight on most vehicles. Maybe I am misunderstanding something.

Burley

Click to expand...

The drums are normally loose fitting around the lugs bolts by nature. That's nothing to be concerned about. The problem I mentioned arises when you remove the rear wheels while the parking brake is on. Once the wheel is removed, the inhernet looseness of the brake drum cause it to "cock" a bit on the lug nuts because pressure from the brakes is still being applied. When you reinstall the wheel in this situation, the brake drum is still "cocked" and your wheel / drum assembly will be slightly loose once you remove the park brake. This is what cause your popping noises when you just about come to a stop.

If you remove the wheels with the parking brake off, that brake pressure is non existant, and the wheel / drum will seat properly on the lug nuts when you go to tighten everything back up.

Just for grins, apply the parking brake, then remove your wheel. Check out the drum and notice how much it "cocks" over on the lug bolts, while you remove the wheel. Now, have someone take off the parking brake while you keep an eye on the drum. Notice how much it moves once the pressure is released....

Ivan