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-   -   VX Drum Brake Troubleshooting (https://www.fuelly.com/forums/f10/vx-drum-brake-troubleshooting-6078.html)

wombosi 09-14-2007 04:58 PM

VX Drum Brake Troubleshooting
 
Hi Everyone,
I'm the guy who helped "93CivicVx" overhaul his rear brakes last weekend.

We're still having some issues. I'll explain:

For the past few days it's been making a bad grinding noise, combined with a rhythmic clacking noise - both clearly coming from the rear brakes.

We took off the drums today. On side there was an obvious "oh ****!" moment when I saw that the clevis had fallen out of it's groove on one side and was grinding against the axle, or whatever that part is. Was starting to grind a crescent shape into it. We popped off the top spring, reset the clevis, manually tightened it enough to hold itself in place.

On the other side, nothing was visually off at all. After straightening out the clevis, both sides looked perfect, with both shoes seated properly in their grooves on the cylinder, all springs connected properly, ebrake cable seated properly and lubricated, all contact spots greased.

We took it for a spin and did the several hardish brakes to reset the adjuster, both forward and in reverse. The car had NO noise for a few minutes and the pedal action was perfect. We had also adjusted the ebrake tension, and the ebrake engages and disengages perfectly.

After about 4 miles of driving, the clacking noise came back. This is a noise that happens when braking to a stop. It's not really audible when cruising at 50 and applying light brake. It seems to be a noise that happens per every revolution of the wheel, and it happens at the same speed as the revolution (ie when braking to a stop doing 45 it will be faster and then slow as the car slows).

I am totally baffled as to what's going. When I changed my girlfriend's brakes ('96 civic DX) in the back, hers was making the EXACT SAME noise BEFORE my job. Nothing was visually off. I simply replaced the shoes and hardware and the noise went away.

Here my only thoughts on what could be going:

1) I think the only thing that can really go wrong in the drum brakes is the adjuster mechanism and the clevis. Assuming everything is in the right position, all the springs are in, etc... Nothing else moves dynamically when applying brake, right?

2) We had mixed up the parts for Left and Right. It took us awhile to figure out which side needed which clevis, but I'm nearly positive I got this right.
On the back right brake, if you tighten the clevis as with a normal screw going into a board, the clevis goes in and shortens its length.
On the back left brake, if you tighten the clevis as with a screw, it EXPANDS.

I tested this with a screwdriver and this is how it works. It's the same way on my civic, tested the same way.

3) We also mixed the hardware for both sides and at first were not sure which long spring to put on top. It seems fairly obvious though that the long spring on top can really only go a certain way, or it either smacks the cylinder or impedes the adjuster, right?

4) Just visually, it almost looks like we were sold the wrong hardware. The top spring is squashed against both the bottom of the cylinder and along the clevis, and the adjuster is barely touching the little cutout in the spring. It seems like it has room to do its thing, though.

5) The drums are brand new and fit perfectly.

I have no idea what could be producing this noise! It's definitely not a metal grinding noise. It sounds like a spring/tension/tapping/clanking noise.

I'm losing sleep over this. I've done this job on two other civics and both are driving beautifully. Why can't I can't this right?

Am I overlooking something really simple? We've had the drums off so many times, compared them to the two other civics. Nothing looks amiss at all.

Thanks for any help. I sincerely appreciate it.

(we're happy at least that the ebrake cables were salvaged and working so beautifully. we saved my friend about $375 so far. i'd really like to get this noise to go away, though.)

THANK YOU.
Ben

mrmad 09-14-2007 06:32 PM

Could it be the wheel bearing?

wombosi 09-14-2007 07:49 PM

well, i doubt it, but that's why i'm asking you guys.

based on the fact that it only happens when applying brake, and that the same thing happened on my girlfriend's car and went away with new shoes and hardware, i can't imagine it's anything other than some part of the brake system.

the car makes no noise when rolling freely, no strange noise when turning.

hmph.

wombosi 09-14-2007 08:03 PM

could it be something silly like it needs more grease on the contact points or something?

should i try taking it all apart again, cleaning everything nicely, relubing, putting back together with new hardware?

it is pretty dirty in there...

Danronian 09-14-2007 08:08 PM

I would take a picture of the odd looking/noisy drum brake, and someone should be able to give you a pointer about what looks wrong. I have already been sold a hardware kit that contained springs that weren't the right size, so I wouldnt rule that out.

If the wheel bearing is bad, I would replace that now since it's good to eliminate every possibility, especially ones you know need to be fixed.

Did you clean the threads of the adjuster and lube it so that it easily spins?

Good luck.

psyshack 09-14-2007 09:24 PM

Your going to have to flip one of the brake adjusters. If I read your post right. BUT Ive been known not to read right.

2) We had mixed up the parts for Left and Right. It took us awhile to figure out which side needed which clevis, but I'm nearly positive I got this right.
On the back right brake, if you tighten the clevis as with a normal screw going into a board, the clevis goes in and shortens its length.
On the back left brake, if you tighten the clevis as with a screw, it EXPANDS.

I tested this with a screwdriver and this is how it works. It's the same way on my civic, tested the same way.

Also look to make sure the adjusting arm is hitting the star wheel right. A buddy of mine had the adjusting lever on the bottom side of a old GM drum brake once and it loosened the brakes while the other tightened the brake. It drove him nuts for a year. One rear drum would loosen up and the other would lock up....

wombosi 09-15-2007 06:03 AM

Quote:

Originally Posted by psyshack (Post 72360)
Your going to have to flip one of the brake adjusters. If I read your post right. BUT Ive been known not to read right.

2) We had mixed up the parts for Left and Right. It took us awhile to figure out which side needed which clevis, but I'm nearly positive I got this right.
On the back right brake, if you tighten the clevis as with a normal screw going into a board, the clevis goes in and shortens its length.
On the back left brake, if you tighten the clevis as with a screw, it EXPANDS.

I tested this with a screwdriver and this is how it works. It's the same way on my civic, tested the same way.

Also look to make sure the adjusting arm is hitting the star wheel right. A buddy of mine had the adjusting lever on the bottom side of a old GM drum brake once and it loosened the brakes while the other tightened the brake. It drove him nuts for a year. One rear drum would loosen up and the other would lock up....

thanks. hehe. wouldn't the adjusters either BOTH be right, or BOTH be wrong?
the adjuster arm is sitting on the tooth of the star wheel perfectly on both sides. on the right back side of the car, w hen the brakes expand, the adjuster arm presses down on the star wheel and expands the clevis, thereby pushing the shoes out further as the pads wear. isn't this how it should be?
otherwise, if it were reversed, it would compress the clevis and after a few weeks the brakes wouldn't be making contact with the drum.
or do i have things completely backwards?

having the clevises swapped would certainly account for one of them having fallen out, but why wouldn't both of them?

the noise IS only coming from one wheel, i'm pretty sure.

i'll try to get a picture of it all this weekend and upload it for you guys to see.

thanks so much,
ben

wombosi 09-15-2007 06:34 AM

Quote:

Originally Posted by Danronian (Post 72355)
I would take a picture of the odd looking/noisy drum brake, and someone should be able to give you a pointer about what looks wrong. I have already been sold a hardware kit that contained springs that weren't the right size, so I wouldnt rule that out.

If the wheel bearing is bad, I would replace that now since it's good to eliminate every possibility, especially ones you know need to be fixed.

Did you clean the threads of the adjuster and lube it so that it easily spins?

Good luck.


yes. the threads of the adjusters were cleaned well with brake cleaner, followed by pb blaster and maybe some silicone grease. i don't remember but they both spin easily.

thanks.

how easy is the wheel bearing job? i don't think i have the energy to do that job as it's not even my car. would love to help my pal out, but getting to the point where i'm laying in bed twitching with visions of brake dust, bent springs, leaking cylinders, misaligned adjuster arms, etc...

VetteOwner 09-15-2007 07:46 AM

if it were wheel bearings i would belive it would make the noise all the time.

sometimes those star wheels have left handed threads(meaning thier the exact opposite tight/loosen as a regular screw)

is the drum smooth(where the pads ride) and not cracked/warped?

wombosi 09-15-2007 07:50 AM

Quote:

Originally Posted by VetteOwner (Post 72397)
if it were wheel bearings i would belive it would make the noise all the time.

sometimes those star wheels have left handed threads(meaning thier the exact opposite tight/loosen as a regular screw)

is the drum smooth(where the pads ride) and not cracked/warped?

yeah, i'm pretty sure the wheel bearings are fine.

the star wheels are working fine. they may be swapped side to side, but i doubt it.

the drums are BRAND NEW, so yes, totally smooth.

the pads on the shoes don't look like they've completed contacted the drum though, as part of the pad is "used" and another part looks like it's never touched anything.

should i try switching the clevises around and see what happens? worst case scenario they fall out and/or jam up?

thanks,
ben


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