Brake shoe rattling noise?

First clue is in.  

With the front end off the ground and wheels still on, I used a rubber mallet to gently tap the disc brake assembly as shown in the photo.  

There was nothing odd, all seemed OK.  It sounded like a rubber mallet tapping against something solid.   I then took my free hand to spin the wheel while using the mallet to continue taping.  As soon as the wheel rotated a little bit - I’m sure too slow for a speedo to even register - the tapping produced a sound as if something is loose.  And if I imagine the sound was more pronounced, it could be what I’ve been hearing - it seems to have a similar signature.  

Slight edit…

I tried the right side, same thing.

Is this normal, or am I on to something?

Ok I realize I titled this post ‘brake shoe’.  I’ve got disc brakes, and brake pads, at all corners.  

I grabbed the caliper by hand and tried to move it around to see how much play exists about the slide pins.  There is a tiny amount of play on the driver’s side, a bit more on the passenger’s side.  I don’t know what normal is, but it did not strike me as abnormal play to me, unless the goal is zero or near zero play.

I then looked at the brake pads from directly above.  There is no noticeable gap between the disc and inboard pad, and only the slightest of gap between the disc and outboard pad.  What is normal?  I can spin the hub and it doesn’t sound like the pad is dragging.  By the way, both ends of both pads appear to have a healthy chamfer.

I then repeated my rubber mallet tap to see if I could better pinpoint the rattling sound I was able to produce earlier.  I think I found the culprit.  The inboard brake pads on both the driver’s and passenger’s side have room to slide just a bit up and down.  The pads have ears (tangs?) that stick proud of the caliper, I assume that is how the pads are held in place.  I could see the ears of the pad vibrate a tiny bit with mallet tapping when simultaneously spinning the hub.   With the hub stationary and mallet put away, I could grab either the upper or lower ear of the inboard pad and I could move the pad up and down.  When the pad reached the end of the small allowable travel, it clanked to a stop.  The outboard pads seem to be held in place better, I was not able to move it.  I made a 4 second video with sound, but it does not appear I can post here.  

In the photo below my finger is pointing to the upper ear of the inboard pad (driver’s side).  I estimate the pad moves up and down maybe 3/16” give or take by pushing or pulling on the ear.

I don’t see anything that looks like an anti-rattle clip.  Perhaps if present they would attach to these ears I played with?  A closer look at the ears appears to show a small clearance on the inside edge of the ear, as if to make room for a clip to mount.  Is there anything else I can adjust to better retain the inner brake pads?

Thanks - Jon

If you have a YouTube account post the video to your YT account then post the link here. You're a supporting member so you should be able to post a video here since you're a supporting member.

Kind of hard to tell from the angle of your pictures, but if your brakes are the typical AC Industries  disk brake kits... it looks.like you are missing the anti-rattle clips in the area where your finger is pointing to.

See attached sample pics of calioer with anti-rattle clip I stalled.

And if indeed they are AC Industries, thise are likely late 1980s VW Rabbit brake pads and antu-rattle clips,  which can be found at most auto-supply stores ( .i.e.- Napa, Autozone), or SoCal iImports who manufactures/sells  those kits and replacement pads.

Thise clips have a tendency to fall off. ( or sometimes.people forget to install them).

Hope this helps

Thanks @Lfepardo. I have seen the clips you are using during my online searches.  I certainly don’t have them installed.  I will be looking to find some.  

@Lfepardo wrote- "...or sometimes people forget to install them"

I'm always amazed at the parts people have left over and think, "well, it works so it must not be needed".  Sometimes WHOLE COOLING SYSTEMS!

Like their backyard engineering is smarter than the factory that designed it...

@ALB posted:

@Lfepardo wrote- "...or sometimes people forget to install them"

I'm always amazed at the parts people have left over and think, "well, it works so it must not be needed".  Sometimes WHOLE COOLING SYSTEMS!

Like their backyard engineering is smarter than the factory that designed it...

.. and sorry for all the typos.  Walking, typing, and being on a call is a dangerous combination ;-)

Sounds like the majority of your noise is caused by the lack of anti-rattle clips.  The clips that are supplied with some kits (I believe AC supplies, EMPI does not) are fair at best.  They are thin spring steel/stainless and are deformed easily.  Order the spring bar style of clip for this pad, they work much better.  Sometimes they require filing the notch out slightly due to manufacturing inconsistencies in the pads and caliper castings (thank you China).  If you want to verify the theory that your noise is pad rattle, drive at a speed and on a road that is noisy and hold gentle pressure with your left foot not he brake.  Noise goes away with slight pressure then pads are the issue.  FYI: it is a very common issue with these particular wide five calipers.

Thanks Carey.  Yesterday I found a post from several years ago that discussed squeezing and rattling brake pads that included a response from you lamenting the difficulty finding a source for clips.  The thread was helpful.  I ordered some of the type shown in a few sample photos above, and as shown below.  Is this the type you recommend?  I saw examples of the spring wire type on GTI forums and they look like they could be more effective, but the calipers looked just a little different than mine.

By the way I do run drum skinz so there isn’t much room between the ear of the outboard brake pad and the drum skin.  I think the spring bar may fit better than the spring wire.

I will try left footing the brake pedal next time I’m out, I suspect I will get the same results as I did using my right foot while coasting.

Thanks - Jon

Dorman started making the spring wire type, which is what I prefer and there is no interference with drumskins.  The type you posted also work, but they are the ones that seem to fatigue and eventually stop working, at least in my experience.   If they don't work for you, or stop working, let me know and I'll have parts dig up the Dorman number.

I love it when a plan comes together.

Search results lead me to believe this is the shape of the wire type that might work (the 117.33999 part number on the bag appears to be a Summit Racing part no longer available).  It just looks like it has a better chance of working.

I found someone who has 5 sets of these anti-rattle clips in stock, for about ten bucks.  For that price I would gladly order a set or two while I wait to receive the strip type clips I already have on order.

Not surprisingly, shipping cost from the Netherlands is more than $100, which is similar to the cost (including shipping) for four used spring clips I found on eBay.  Nee.

I did send a note to Dorman asking if they provide these clips as Carey indicated.

While waiting for the strip type anti-rattle clips that I ordered to arrive, I kept searching for a source for the spring wire type for a reasonable price.  A week ago I found a source so I ordered two sets of four clips at $7 a set.  

The spring wire clips arrived yesterday, I got them installed today and I’m happy to report that during a 15 minute drive this evening I did not hear one bit of brake pad rattle.  I’m happier to report that my car stopped when directed to do so.

A big thanks to you, the fine folks on this forum for all of your helpful advice.

I love it when a plan comes together.

Fabulous!

Excellent!

For future member reference, could you post the source where you found/sourced the wire clips?

Many thanks, and happy motoring!!!

Certainly.  The clips I found are a Centric part number: 117.33016.

I tried the ‘where to buy’ button, that pointed me to a wholesale parts store with a location very near me, but they were not responsive.

I then searched by the part number and found a few potential sources.  I bought them from Summit.  They were $7/set.  The image showed four clips but the description didn’t specify if a set was comprised of two or four clips.  Shipping was $12 whether I ordered one set or two, so for an extra $7 I ordered two sets.  According to Carey, only one clip per caliper is needed to solve the rattling problem, so now that I know these clips actually fit, 8 clips effectively gives me four sets.  

At the time I ordered my sets, the Summit page indicated their inventory was ‘more than 10.’  After I ordered my two sets, I now notice their inventory shows as only nine.  Order soon!

For completeness, here are a few other search results in case this helps anyone searching our forum in the future.

By the way, with a little finagling the clip can be installed without removing the caliper.

By coincidence, yesterday I also received the flat bar/tab clips that I ordered first.  By inspection they can’t be installed without removing the caliper.

Jon

Thank you for the info.   As it turns out I lost a clip this weekend...  so great time to order a  set !

Happy motoring!

Glad this worked out. And thanks for the clip source. The wire ones do get lost/misplaced.