Turbo X_J

The drag & release when turning the drum by hand is completely normal due to the fact the drums float on the wheel studs and axle hub. This would only be when turning the drum by hand, in operation the fact the drums are secured and and then centered, the momentum of the vehicle would make this unnoticeable. "Backing off" the shoes isn't really possible because the brake pedal would simply go all the way to the floor. A hydraulic system can't function with a hole in it.
First thing I would check are the rotors for run out, then insure that neither the pads or calipers are seized. After that I would check that the wheels and tires are true. What toque are you applying to the lug nuts and how are they tightened? If there is still a pulsation in the brake system I would suspect the pivot pin on one of the backing plates is loose or somehow damaged or the surface that the shoe slides on is not allowing the shoe to move and retract freely allowing the entire brake assembly to malfunction.

ntrabbit

Thanks for the detailed inputs! I'll address these notes:

-> When I'm turning the drums by hand, I have the wheels on and torqued, so I hope that they are centered and secured
-> I always torque my lug nuts in a star pattern after removing wheels: 100ft/lbs, and I use anti-seize on the studs
-> Front brake pads and rotors are new, and I had the rotors checked for warpage. All good.
-> When I rebuilt the rear drums, I greased all the contact points on the backing plate for the shoes, so I hope they aren't sticking
-> Tires are relatively new michelins and I just had them rebalanced earlier this summer. I just rotated them as well.

I'm not sure about the pivot pin on the backing plate: I'm not familiar with this. Can you elaborate? Do you mean the spring loaded pins that hold the shoes on?

ntrabbit

Just a quick update: When I removed & inspected the drums over the weekend, I gave them a thorough cleaning (brakleen), reassembled, and tried to really get a nice adjustment that was just barely rubbing while spinning the wheels. All-in-all, everything feels pretty good right now. BUT... I only have to drive 7 miles to work each way, so they don't get hot. In the past, this would happen, until I had to drive a long way and get heat in to the drums, in which the pulsation would return.

I have to drive about 100 miles this weekend (through Denver), so i'll be able to get some good heat in to the brakes. I'll post back if the problem amplifies as it has in the past. But right now, they are working pretty well (hardly noticeable pulsation). So odd.

Turbo X_J

Anchor/pivot pin


100 ft lbs with never-seize is bad juju. Torque specs are almost always given for clean, dry threads.

Anony

Rock Auto current Bendix drums (which are fair quality) BENDIX PDR0570 for $21.79 each

http://www.rockauto.com/en/catalog/j...+hub,drum,1744

Rock Auto also has closeout deals some of which may be brake parts. To view their current closeouts for a 2000 Jeep Cherokee

http://www.rockauto.com/RSS/vehiclef...l=en&html=true

To find closeout deals for other vehicles go to your year vehicle and engine, from the main rockauto index. At the end of this url for your vehicle will be a number such as "1363384" for 2000 Cherokee XJ with 4.0 engine.

Take this number and replace "xxxxxxx" after carcode= with your own number.

www.rockauto.com / RSS/ vehiclefeeds.php ?carcode=xxxxxxx&m=wc&l=en&html=true

You many need to click a few more times, and a Rockauto closeout parts page will eventually be displayed.

I always pic up spare drums and brake pads as drums don't seem to last the same as they once did.

If you find drums manufactured in the USA they usually are going to cost two to four times more than China made drums which aren't too terrible, some of the USA manus now have factories they use that are located in China with Chinese workers.

China and some other countries don't have as strict pollution laws and regulations for manufacturing. A smelter or foundry in China could not exist in the USA because of these regulations, so US products of this type are normally more expensive as the factories need to pass certain standards and anti-pollution regulations.

Other countries such as China can used older manufacturing methods which don't necessarily produce lesser quality automotive products (unless they cut corners, etc.) but products that produce more pollution during manufacturing.

Though countries such as China have started to re-write and enforce more anti-pollution laws some of which can be sort of strange as I remember reading one polluter in china was give the death penalty. I can't remember the exact pollution crime but the punishment is death by hanging or something similar.

Here in the US they just fine the company which many just pay the fines and then keep polluting anyway.

ntrabbit

For $22/ea. it would be hard NOT to try those drums. That's a steal - thanks for the link!

ntrabbit

Gah! Ok.

When I was a mechanic, the only time I ever saw rotors/drums warped from incorrect torquing was when the lug torques were varying. ie: Two are SUPER tight, and three are correct. So hopefully the consistent torquing, that is somewhat close to spec, won't be an issue. Thanks for the heads up though.