Drum brake problem

A year ago I replaced the rear drum brakes on my (wifes) '99 Taurus. I put in new shoes, drums, spring hardware and wheel cylinders. Lately there's been a lot of grinding/squeaking from the rear brakes when they're applied. It doesn't do it when I apply the parking brake when the car is moving (about 10-15mph). I pulled off the drums (look OK), the shoes look new, nothing is leaking, etc. I lightly sanded the drums and shoes and cleaned them up with brake cleaner. The sound went away for a few weeks and then returned. There wasn't any noise for at least a few months after I replaced everything. I don't drive this car much, but I do all the maintenance on it. The only thing I can think of is that I got a bad batch of shoes and or drums. I bought them from Carquest Auto Parts. Any ideas? Thanks!

Sometimes brakes will vibrate when applied. Not a thing wrong with it, but when you hear something back there, you think it's not right. If that's all it is, then take off the shoes and with a coarse file, file down the leading and trailing edges of the braking material at an angle. In fact, some shoes come already made this way. On brake pads, often there are antirattle shims and you can also use an antisqueal/antirattle compound for this problem. If it is only a one time thing, sometimes gravel can do that, but if it is still there after clearing out the drum and back plate, then its something else.

From there I'd be sure that all of your brake hardware is installed correctly. Is any of it being rubbed on? Did you lube all the contact points? Are the wheel cylinder bolts tight? Is the hub seated all the way? Could something be vibrating on your wheel, hubcap, etc?

I'm pretty sure I installed and lubed everything correctly (one side at a time, plus I've done them before on other vehicles). All the bolts are tight. The shoes came with a bit of an edge on them. It almost sounds like when disc brakes are a little rusty from sitting outside for a while and you first hit them the pads are contacting the rusty areas of the rotors it creates a slight grinding sound. I'm going to pull everything again and see if any weird wear patterns are developing. Otherwise I'm stumped.

Also, in some cases, the leading shoe is shorter than the trailing shoe. Take both drums off and compare the amount of friction material on all four brake shoes. If two are shorter (along the circumference) than the other two, the forward shoe on each side should be the shorter shoe. If not, that could be contributing to your noise and explain why it keeps coming back.

-Rod

Also, in some cases, the leading shoe is shorter than the trailing shoe. Take both drums off and compare the amount of friction material on all four brake shoes. If two are shorter (along the circumference) than the other two, the forward shoe on each side should be the shorter shoe. If not, that could be contributing to your noise and explain why it keeps coming back.

-Rod
Did they change this Rod? Back in the day, when cars were cars, the shoes with the shorter lining went on the rearmost position.

OK- I was wrong about a few things:

1) The shoes and drums came from 2 different parts stores (shoes are Raybestos PG Plus from Checker Auto/Parts America and the drums were from Carquest. Maybe a compatibility problem?

2) The leading and trailing edges of the shoes don't have an edge on them. So like tripletdaddy mentioned maybe I should file a sloped edge on them. But looking back at the photos I have taken, the original shoes didn't have that sloped edge, and neither do the rear shoes on my van (old and new shoes).

It looks like you can only install the shoes a certain way, as the leading shoe has a nub for the adjusting lever and the trailing shoe had the attachment points for the parking brake lever.

Did they change this Rod? Back in the day, when cars were cars, the shoes with the shorter lining went on the rearmost position.

I don't believe they changed this, I'm going off memory here as I haven't had a car with drum brakes for a long time. Dangit, you've got me questioning my memory now....

-Rod

From http://autorepair.about.com/cs/doityourself/a/aa031701a_2.htm

"NOTE: In many cases the primary shoe material is longer than the secondary shoe material. The longer shoe always goes towards the rear of the car and the short shoe towards the front."

And this (http://www.g503.com/forums/viewtopic.php?t=110655&highlight=&sid=3e8dee54d64ab24f43367320060e58b8) site would suggest we're both right, in certain cases. ;)

-Rod

Three more monkeys to throw a wrench:

When replacing your shoes, did they have a different lining material?

Was the new brake hardware a cheap aftermarket or Bendix/oem? Doing my brakes on my Escort, I noticed a subtle difference in the parts. If you still have the originals, you may be able to figure out if it's enough to be not "right". I noticed the aftermarket set I had also did not seem to be made of as high a quality spring steel as it was more fatigued than the original, ie. easier to stretch. Enough so, I put back some of the original springs which were still in good condition.

I'm sure you checked them for looseness, but for imperceptable looseness, you need to tap them on the backing plate on a hard suface or a hammer to listen for a buzz or off sound.

Have you considered swapping the brake shoes side to side to see if the sound moves with them? If you want to do the drums too, just swap them separately from the shoe swap.

Would love to hear what ails them or is it you? :)

The spring hardware and shoes are Raybestos PG Plus brand and the drums were just an OEM type from Carquest (the receipt doesn't show a brand name but I remember the parts guy stating these were OEM or better). It will be a couple of weeks before I can take a look at the brakes as my heated garage at work is a mess. I'll try swapping sides with the drums and see if that makes a difference. Otherwise I'm going to replace the drums and shoes again with a different brand.

UPDATE: Here's what I found out about the rear drum setup on my car. Apparantly the noise I'm hearing is the shoes not making 100% contact with the drum. I spoke to one of our fleet mechanics and he said that the best way to get the drums/shoes to mate exactly is to have the shoes arced. He stated that the fleet shop used to do them years ago but stopped due to asbestoes dust. Looking up the process on web showed that not a lot of shops do this anymore. Since everything else seems to be working except for the noise I'm just going to leave it alone. Thanks for all the suggestions.

thats a good idea road & if that is your problem the noise should go away as brakes wear in. Good Luck + let us no!!!!

UPDATE: I ended up replacing the drums and the shoes. The noise is gone and so is a constant vibration above 70mph. I think the drums were out of round or machined wrong. Wife is no happy that there's no more noise. Now if I can only figure out the damned cruise control...