New Disc Brakes Squealing...Dumbfounded

[coolwind57]

Hey guys, let  me run something past you before I go throwing money at this problem.  By the way, I read maybe 10 topics on this issue here at the forum and couldn't really find a solution specific to what I'm experiencing.

 

Two weeks ago, I replaced my rotors, calipers and pads.  Calipers came with new, well-greased slider pins and pin cover boots.  I did reuse the anti-rattle retainer clips for the pads, as they appeared to be in fine, serviceable condition.  Here's the symptoms:  After the vehicle is driven and warmed up, I usually always get a metal-to-metal "ringing" squealing sound at low speeds.  It instantly disappears when brakes are applied.   

 

I had my wife drive at a creep while I walked along side the vehicle in an attempt to pinpoint the sound source.  I never was able to pinpoint with absolute certainty, but my guess was passenger-side front.  

 

So the other day, I took the front brakes apart, seeking for anything obvious.  I checked for debris--all clean (again, most are all new parts).  Slider pins were clean and still lubed.  Took pads off, re-sanded the backs and applied anti-squeal spray.  Lightly sanded the braking surface a bit while I was at it, thinking that there might be some "extra" metal in the pads.  Inspected and lubed the contact surface where the pads notch onto the knuckle.  No excessive wear there either, by the way.  Inspected the anti-rattle retainer clips for the pads.  Looked for shiny wear spots, nothing.  Inspected them to see if they were making contact anywhere once they were installed.  Nothing--we've got good clearances there.     

 

I'd read that pads can be installed backwards, but I'm quite sure my pads were installed with the correct orientation.  

 

Anyhow, I put the brakes back together, assuring all was clean and went back together.  I even took my rear drums off, checking them, knocking dust out and reinstalling.  Those shoes were replaced one year ago.  All looked good in there.   To my disappointment, once I was back rolling down the road, none of this killed the squeal.  

 

My new pads are Wearever SILVER Semi-metallic, $15.99 from Advance Auto which are not the super premium pads.  It was all they had in stock at the time. 

 

I'd really like to see if there is anything else I can check before I go buy premium Duralast Golds at $19.95 or even Duralast Max from Autozone at $47.99.  The noise does immediately go away the moment I step on the brake pedal and returns the  moment I let off.  This seems to tell me that its likely a brake issue, but perhaps not.   Either it goes away at highway speeds or my aggressive tire noise covers it, but I do hear it faintly at 0-20mph--enough to drive me nuts.

 

What else should I check?  This does seem to be a brake-related issue, right?  can't think of anything else that would create metal-to-metal noise that goes away when one applies the brakes.

 

[yxmj]

Any chance the dust shield is rubbing on the rotor?

[HOrnbrod]

3 hours ago, coolwind57 said:

I'd read that pads can be installed backwards, but I'm quite sure my pads were installed with the correct orientation.

 

I went through this years ago on my 2WD front calipers. Your sig doesn't say if you are 2WD or 4WD. The inboard and outboard pads are different, and they will install backwards. I know, I did it, and the squealing drove me nuts until I finally figured out what happened. Don't know if this pertains to the 4WD calipers or not:

 

From 3-30-2010

"Okay, I'm dragging this up yet once more because I FINALLY GOT THE DAMN THING FIXED!! YAAAA!

 

I'm gonna tell you all what it was in the hopes that it will save my 2WD MJ brothers the aggravation I've gone through tracking down the damn brake squeal. :fs1:

 

First off, the inboard and outboard front disk brake pads LOOK identical, but they are not. The inboard pad has the smaller pad liner, about 3/8" difference in length. BUT they will fit on either way. The last brake pad set I got had three outboard pads and one inboard. I missed it and stuck the two inboard pads on the right front wheel. The problem occurs when you mount up the caliper after fitting the pads and anti-rattle clips (more on these later). When you tighten down the two slide pins that the caliper rides on, the top pin bottoms out just enough to C#*@ the caliper so that it will not ride squarely on the caliper bracket sliding surfaces, thus creating squeal. It bottomed out because I had two of the longer outboard pads on and the extra material on the inboard pad causes the caliper pin to bottom out. Of course, there's nothing in the FSM telling you this, just a fuzzy picture that shows the material difference between the inboard and outboard shoes.

 

Second problem was the anti-rattle clips. They are shaped like an elongated "C". The open part of the "C" must face AWAY from the rotor, otherwise the pad will rattle around in the caliper. Of course, these clips will go on 180 degrees out too with the open part of the "C" facing TOWARD the rotor (I installed one of them on each side this way) which causes even more squeal. :fs1: The FSM does say to install the bottom clip with the open end facing away from the rotor, but says nothing about the top clip. Naturally I put them in backwards. :wall:

 

The cause of the squeal was painfully obvious when I pulled everything down to change out the pads yet again with some new ceramic pads. There were bright shiny spots on the caliper and caliper bracket sliding surfaces. Luckily there was no permanent damage done though. Anyhow, hope this helps y'all next time you change front pads on your 2WD. :cheers:"

 

 

 

 

 

 

 

[coolwind57]

14 hours ago, yxmj said:

Any chance the dust shield is rubbing on the rotor?

 

Certainly was what I imagined the problem as being, but it wasn't.  I have some advance corrosion on the driver's side and removed anything close to touching the rotor.  Afterwards, both sides were well away from the rotors.

 

12 hours ago, HOrnbrod said:

I went through this years ago on my 2WD front calipers. Your sig doesn't say if you are 2WD or 4WD. The inboard and outboard pads are different, and they will install backwards. I know, I did it, and the squealing drove me nuts until I finally figured out what happened. Don't know if this pertains to the 4WD calipers or not:

 

I'm anxious to open her up again and check for this stuff.  I'm hoping you're on to something despite mine being 4WD vs your 2WD.  

 

12 hours ago, HOrnbrod said:

The last brake pad set I got had three outboard pads and one inboard.

 

Oh, my Lord....I would be PISSED!  haha  Nothing more infuriating than discovering that you'd gotten wrong parts in the middle of a job.

[coolwind57]

I think this is mystery solved:

 

I am frustrated that I did not see this before the install.  I am quite sure that it is a factory defect as there is no other sign of damage caused by any improper installation.  I did confirm that the pads were installed correctly before I removed them, with the shorter pad installed inboard and the anti-rattle clips installed right.  It was after I removed them that I noticed that the pad on one was jacked up.  

 

It was easier to overlook this flaw in person than in my closeup pictures, but I should had better inspected them before the install, hands down.  Dumb mistake on my part.  Advance Auto replaced them with no arguments.   

 

Learn from my mistake, fellas.  Thoroughly inspect your parts before the purchase!!

 

New replacement brake pads are great, no noise.  Copper color you see in the pics is anti-seize paste.  I prefer it over grease for this particular application.   

 

I am relieved. 

[HOrnbrod]

Glad you found it.    Looks like another example of C.R.A.P.'s.

[Strokermjcomanche]

I always try to get pads that have chamfers at the ends of the lining , I've never had that type of pad squeal .... Granted I see that really wasn't your issue , but something to consider in the future. 

 

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