I have a 2011 outback with about 130,000 miles on it.  I had new front pads, rotors and hardware installed a while ago.  I live on a dirt road and lately I have been hearing a rattling sound coming form the driver’s side front wheel when I hit bumps, there are a lot of bumps.  If I apply the brakes the rattling stops so I suspect something in the brakes.  The parts were from Rock Auto, a Power Stop kit with pads (shims preinstalled) rotors and hardware.  I purchased the parts and had them installed at a local shop as I recovering from a twisted knee.  Any ideas would be much appreciated.

More than likely it is the caliper bracket mounting bolts not tight or the caliper guide pins loose or worn.

Check it out soon. You don't want the caliper popping up and lock the wheel from turning. That may not happen, but you know about murphy's law.

Our 95 acts the same way on bumps. It is the hole in the caliper for the guide pins is worn and lets the caliper bounce up and down only a little, but it is noisy.

I finally got a nice day and was able to look into the brakes.  All the bolts were tight so that was not the problem.  On the driver's side, there was some play as I pushed on the caliper with my hand. The passenger side was tight, no play.    I removed the caliper and saw that all shims and hardware were in place.   I put the caliper back in place and did a test drive on my bumpy road.  The noise was gone.  But over the next few days, the noise started to come back, not as loud as it was before but there.    I would assume that since it stopped for a while that the cause would not be worn holes for the guide pins.  Is it possible that the piston is going back into the caliper too far and causing the play?  If so what would cause that?  Would it be worth bleeding the brakes but the pedal feels firm.

Maybe it's not brakes but balljoints or some other suspension bits? Could be that braking puts load on the suspension and stops the rattling.

Oh just saw the part where you found some caliper play by hand.  Could be a worn wheel bearing causing pad knockback as the rotor wobbles when you go through bumps.

Edited December 29, 20196 yr by nvu

Pry the outer side of the caliper away from the rotor just a little to push the piston in about an eighth inch. If you can wiggle or move the caliper up and down, the guide pins a worn.

I have a big C-clamp to do that.

Thanks for the replies.  I will try Rampage suggestion when I get another decent day.  Still wonder if it was worn guide pins why it got quiet for a couple of days but certainly worth a try. Will post how it goes.

Caliper slide pin rubber sleeves. Just buy new slide pins from Subaru. 

GD

Slide pin bushings.  They can swell/stretch and hang the one side of the caliper. 
 

using old school generic grease is often problematic with the bushings. If that’s the case then address all of them now,  or just the one problematic one.  Use something silicon based appropriate for pins with bushings.  I use Sil Glyde. Older Subaru’s and vehicles never had bushing and it didn’t matter   

Replace, or just throw them away and run them with no bushings. I do it all the time for hundreds of thousands of miles.  They’re not necessary at al. 

I'm not sure what these bushings are.  Are they inside the holes the guide pins go through?  Is there an exploded diagram of the caliper that I can see them on?

 

 

You have to buy the whole pin anyway. Just follow my advice. Buy new pins, slam them in. Done. 

GD

thanks for the diagram, a big help, and all the other advice.  I have to work outdoors  so when I get a nice day I will try what has been suggested.

I finally got a nice day here and installed new guide pins, aftermarket pins.  I did not replace the bushing.  No change still have the noise.  When I had the caliper off I noticed that the pads could move up and down quite a bit inside the hardware.   The noise I hear sounds heavier than that sound to me but would it make sense to replace the hardware or maybe just buy a new caliper with bracket?  I don't think this is dangerous but it is annoying, I drive the road every day so I hear it all the time.

1 hour ago, bluebird said:

When I had the caliper off I noticed that the pads could move up and down quite a bit inside the hardware

The caliper bracket should have shims top and bottom that make the pad fit tight. All the good pads come with them.

Sometimes you have to clean rust off the bracket so the pad is not too tight with the shims.

Ok here is an update.  My bad knee behaving better and some good weather allowed me to continue to try to solve this problem.  Today I installed a reman caliper and bracket.  Noise is still there.  But as in the past when I have had the caliper off when everything is put back together the noise is gone for about the first 1/2 mile down my dirt road Then it comes back.  I talked to a mechanic about it today and he said it is likely the sway bar links. Remember when I touch the brakes the noise goes away.  He said that happens with bad sway bar links as well.  Does anyone have an opinion about this?  How bad a job is replacing the links?

depends on how rusty things are.

sway bar links are pretty easy as long as the bolts aren't rusted real bad

 

To find out if it is the sway bar links, remove both of them and go for a ride.

What shape are the bushings in where the sway bar mounts to the frame? I've seen them wear and the bar hits metal.

Are the inner and outer tie rod ends tight? When you apply the brakes the front wheels want to turn outwards which would tighten up a loose tie rod end.

Subaru Technical service bulletin 05-49-10R

Replace the strut spring

Thanks for all the replies, I think I will try Rampage's suggestion first and see what that reveals.  I'm thinking that what might account for the temporary quiet right after putting everything back together would be that the wheels were hanging free and that might have stretched out the links for a short time.  Can the links be removed with the wheels not hanging free?  I like to work under the car with it up on my ramps.  

22 minutes ago, bluebird said:

Can the links be removed with the wheels not hanging free?

Yes. Both wheels up or down.

On 3/6/2020 at 8:42 AM, idosubaru said:

Replace the strut spring

I'm curious, how would applying the brakes stop the rattle if it was caused by the strut spring?

I'll have to find that bulletin.

The bulletin is talking about a squeak not a rattle.

Edited March 9, 20206 yr by Rampage

I tried to remove the driver's side link could not get it off.  The problem was my 6mm hex wrench would not fit into the end of the threaded shaft.  It did fit right into the replacement link I had on had to use if needed.  The next size down that I had was too small. I tried to hold the shaft with channel locks and got the bottom link nut about 1/3 of the way off before it tightened up and the shaft turned in the ball joint.  Hope this makes sense.   is 6mm the correct hex wretch?  If I can get the old link off is it OK to drive the car with just the driver's side link removed?  The noise is definitely on the driver's side.  I' m about ready to take it a shop.

Try some PB Blaster or Freeze Off to get the nuts off. I have a Dremel tool with a wire brush wheel and it works wonders on rusty threads. I also bought an induction heater. It works good.

I don't know about the wrench size.

I wonder if the ball joints are loose on the drivers side sway bar link.

freeze off is some good stuff - not cheap, but it does work about 99% of the time when used as directed

try pb blaster, then tighten a little, then loosen....