I have been having a problem with front disc brake squeal last year and now this year. The brakes have been on for 2 years. Pads are in good shape(only about 20% used). Should I replace pads with a different material or could there be something else making noise?

 

Have you used copper slip on the pad backs and all metal to metal contact points?

 

Your pads are probably dragging due to rust , dust and lack of lube at contact points

 

Wouldn't hurt to run some light sandpaper over the pads themselves - sometimes they get a glaze on them that produces noise.
Ken

 

I'd inspect the mating surfaces for glazing, oxidation, debris, oil/brake fluid contamination or anything else that shouldn't be.

Before I install new pads, I have my local source do a "glaze-cut" on rotors which isn't a deep cut unless it needs it to be to restore lateral run-out. I've had good luck with Permatex "Disc Brake Quiet" but noise can come from other issues after the pads are cushioned / adhered.

Some pads are slotted in the middle to offload debris and break up surface area resonance. I've seen people cut a slot with a hacksaw. Some folks die-grind a small bevel on all of the pad edges. In respect to new pads, I've heard that some of the newer, harder, metallic composites are prone to noise. Never hurts to pick up the horn and chat with a Bendix or other tech-support source regarding pad material.

Good Luck,

Dawg-a-roo

 

I've gone round and round with noisy pads on my non Ford trucks. Tried several different brands and types of pads. Got tired of having to frequently clean them up to stop being so damn noisy. Went to factory (Toyota) and no more noise.

I also had noise problems with my kids 66 Mustangs that had Granada disc conversions. The cheap organic pads ended up being the quietest and work as well as the semi-metallic or ceramic pads.

Just some food for thought.

 

Thanks everyone for all your input. All good thing to consider. I will check with a brake company to se what they have to say.

 

Many years ago I worked for Midas. 68% brake market share, entire U.S. - we did a LOT of brakes. There are a number of things you can try - bevel the leading edge of the pads, a light smear of silicone grease on the back of the pads, anti-rattle shims on the back of the pads, etc. But what it all boils down to is the pads are vibrating against the metal contact points so fast that the frequency of the sound becomes a squeal. Friction materials can be made of a plethora of different substances - walnut shells, aramids, carbons, binding resins, yadda, yadda, yadda. The softer yet longer lasting ingredients are more expensive. Add in dinky rotors and drums which save the OE money yet heat up fast (smaller swept area equals more heat generated.) Then there's the trade-offs - dusting and short life...

So, how do you reduce the noise? (I'm always hesitant to say 'eliminate' as under some circumstances even the best driver's have to endure conditions that will end up causing noise) First and foremost, don't buy the economy or mid-grade friction. False economy. While it may work for a few it's almost always a guarantee for noise down the road. Wagner ThermoQuiet pads are my aftermarket favorites, I have used them on all my cars since they were introduced. A good balance between no/minimal noise and pad life. There may be better stopping pads out there but you'll be opening yourself up to the trade-offs. Rotors don't always need to be machined. A GM TSB form many, many years ago broached the subject and their take is if the rotor has grooves less than .060" (don't shoot me if my memory isn't exact) and has no other deficiencies (basically, not below minimum spec, lateral run-out within tolerance) there is no way resurfacing can provide the mirror finish that the polishing the previous set of pads provided. Mirror finish equals less chance to cause vibration and create noise. Keep this in mind when having drums and rotors resurfaced. Pay attention to how smooth the finished machining is. Always wash a freshly resurfaced drum or rotor prior to installing. No reason to embed hard iron filings in your premium friction...

Always replace the hardware with each set of new pads. Dust boots, caliper slides, etc. are exposed not only to the elements but also to extreme pressures and temperature. Make certain that the pads fit well and slide easily but not so loose that they will swim around in their brackets. Older GM pads (as an example) had outer pads that needed to have the outer pads' 'ears' folded to hold them tightly to the caliper. Loose pads equal clicking which in itself is annoying but also that clicking is the precursor to squealing.

Clean all mounting points - caliper brackets to knuckles, pad slip-ways, etc. Lubricate where required. Use a good brake lube. I'm not a big fan of the stuff that comes in the tiny tubes included with some parts. I can give them props for trying but that stuff will wash away in the first puddle. Use this:http://tinyurl.com/hdzpf32 or:http://tinyurl.com/zx7p7qa The first one can be used on just about anything. It won't attack rubber or plastic, water doesn't bother it and I also use it as a dielectric grease - inside spark boots to keep them from sticking, water leaking in, put it in the little well in a HEI distributor rotor, under the blade, to prevent arc-through. The second product is great for brakes only but can't be used as widely (especially not as dielectric.) Anyway, a thin smear of the lube should be placed in the grooves where the pad ends slide, on the back of the pads where the caliper piston/bracket ride. Also use in any pin/bolt boots, hardware leaf springs, etc.

If those calipers haven't been rebuilt in years, do it! The only thing that retracts the pistons from the pads is that little square-cut 'o'-ring inside. As pressure is applied the piston ***** that 'o'-ring as it extends and when pressure is removed the 'o'-ring will want to relax to its normal state, 'somewhat' effectively pulling the piston slightly back. 'Somewhat' meaning that crud build-up in the caliper will inhibit that action, the pads will continue to drag as the piston can't retract and the pads will continue to do the slow cooker thing. Picture this: bake some cookies until done, yet soft. Now slide one across the kitchen counter. Now burn the heck out of a batch and slide one of those. Notice any difference in the noise they make?

Never, NEVER, use a 'disc brake quiet' type substance. They never, ever work. If someone tells you they do it's only because they didn't have a problem to begin. What WILL happen is that crap will turn hard as a rock, melt through at the exact places it is supposed to be working and will stick to the piston boot which will cause you to rip it the next time you remove the pads.

Long post, simple things. Can't begin to tell you how many peeps don't do these simple things and then ask, "Why..." I've made a darn good living by just doing the things others don't. And if you still have a squeal consider this: try the OE friction. It's expensive for a reason. And if all this doesn't work you are probably one of those drivers that have a challenging drive or you're just tough on brakes.