Rear drum knocking while driving (not braking)

[djchoragos]

Hey all

I recently attempted to replace the rear brake shoes on my 01 Accord. Everything seemed to go reasonably well, but now when the brakes heat up I get a loud knocking and vibration while driving that goes away while braking. I popped the drum off last night and backed off the adjustment as the drum was hanging on one spot during rotation. This seemed to make it worse (though some nimnal did stop suddenly in front of me, so I had to emergency brake and heat everything up). It has the original drums. I've ordered a new set of drums to pop on and see if that helps, but I would appreciate any suggestions. I'm totally self-taught on these kinds of things so feel free to talk to me like a child--I might have done something really stupid (you never know). Thanks!

As a second, related question, there was no problem on my little test drive last night so I drove to work this morning. About 3/4 of the way there was when this started, and kept getting progressively worse. Understanding that you don't know exactly what the problem is, do you think it's reasonably ok to drive home (about 10 miles and I can stay off the highway)?

Problem:
Knocking and vibration from rear passenger drum brake after replacing brake shoes, only while driving.
Car:
2001 Accord LX 4 cylinder
What I did:
Took the drum off, backed down the tension on the adjustment screws.
Other:
Drives and feels fine until the brakes heat up.

[jeffcoslacker]

Usually that particular sound from a drum brake is associated with a broken or stretched shoe return spring....

What happens is the shoes is not being held tightly to the post that it sits on at rest, and so the drum grabs it, pulls it outward, this rotates the whole shoe assembly and makes it release, and it snaps back against the post and makes that loud knocking sound. This happens over and over all the time unless the brakes are applied, in which case it's being pressed firmly into the drum constantly, so no noise.

Other than that, the parking brake cable link can sometimes be assembled in a way that makes the secondary shoe try to stand up off the post....if that happened, you'll get the same effect....if it seemed like it didn't want to lay down easily against the post when it went back together, I'd suspect this may be the cause...

[djchoragos]

Thanks! The shoe return spring is definitely not broken, but could well be stretched. Could a similar scenario arise if I have the tension too low on the adjustment?

I'll do a disassembly tonight and post what I find for others that may have this problem. I don't recall an issue getting the other shoe to sit on the post, but possibly. The whole thing was a pain in the rear so I may just not have noticed.

[djchoragos]

OK, well I isolated and fixed the problem. I'm posting it here in case anyone else has the same issue, but I have to admit, I'm horribly embarrassed.

I was changing the shoes on the driver's side when the load point for the jack on my chassis failed (yeah, no bueno). Thankfully I always have a spare stand slightly forward, so no huge deal. However, I put everything back quickly, and somewhat in a panic...aaaaand never tightened the lugs all the way down (just the initial tightening while it was in the air). The knocking sounded like it came from the passenger side, so I missed it entirely. Tightened everything back up and it's all fine now.

Like I said...horribly embarrassing. Thanks for the help.

[dderolph]

Originally Posted by djchoragos

I was changing the shoes on the driver's side when the load point for the jack on my chassis failed ...

Can you explain in more detail what happened? Did it just sort of collapse? In the future, how will you jack up that corner of the car?

[djchoragos]

The jack point bent outwards, allowing the jack to slide towards the outside of the car. It didn't come completely off, but now there is no level jacking surface. The jack stand was there to catch it on a non-reinforced part.

I guess when it comes time to jack it up again, I'll have to use a hydraulic jack under the tow point in the rear. It's either that or move the jack forward on the chassis.

[jeffcoslacker]

If you're talking about the loops under the body you might not wanna lift under those...they aren't really structural. I used to tow and we were advised to never try to pull a car by them because they'll tear right off....their only function was to secure the car in transport when being shipped.

Most unibody cars if you get a jack up under the box channels in the front floorboard they'll take the weight just fine. With my floor jack I can just keep going up until both wheels on that side are off the ground...

Trailing arm to body brackets are pretty safe too for lifting the rear, but put a thin block of wood between the jack pad and the bracket...or since your hoist point already crushed, just continue to use that spot with a block of wood....it's not gonna crush any more, unless it failed from rust or something...