Rick's Free Auto Repair Advice

brakes squealing

How to stop brakes from squealing or making noise

Brakes squealing noise is the most common complaint from drivers. If you’ve recently replace the brakes yourself and now the brakes squeal, or you’ve had them replaced at a shop and now have brake noise, chances are the brake job wasn’t done properly. Here are the steps you can take eliminate the problem.

In the automotive industry, brakes squeal is common referred to as NVH, Noise, Vibration, Harshness

Step 1: Buy high quality brake pads. Economy, “no-name,” and many

assortment of brake pads

Brake pads come in different quality levels

private labeled store brands are made with older less expensive friction materials that are pretty much guaranteed to make brakes squeal. High quality pads come with new noise reducing shims and new anti-rattle clips (where factory equipped). If you buy a set of pads and they don’t come with shims or clips, buy them separately.

You CANNOT reuse old shims or clips—well, unless you want to hear your brakes squeal.

economy and premium brake pads

Read this post on brake pads and brake jobs

 

 

 

Step 2: Clean everything. When cast iron and steel come in contact with water and humidity, they form rust. Since rust expands as it forms, it can cause brake parts to bind. The most common example of this is between the hub and the rotor hat area, and between the brake abutment or caliper bracket and the anti-rattle clips. This phenomenon is called “rust jacking.” When it occurs between the hub and rotor hat, it cocks the rotor, causing lateral runout and disc thickness variation. Read this post to learn more about brake pedal vibration and pulsation.

disc brake hardware

Anti-rattle clips

However, when rust jacking occurs between the abutment and the anti-rattle clips, the decreased clearance causes the pad ears to bind against the clips. That causes uneven pad wear, brakes squeal, vibration, overheating, and premature failure.

So wire brush the abutment areas and apply a thin coating of high temperature brake grease before installing the anti-rattle clips. Do NOT lube the clips. That’ll just accumulate brake and road dirt.

Step 3: Install new shims. Brakes squeal is caused by vibration betweenbrake pad shims the rotor and pads. The rotor acts like an LP record and the pads act as the stylus. Wherever the brake pad backing plate comes in contact with the caliper there’s the opportunity to transmit the vibration. Noise reduction shims act as insulators. Many companies recommend applying high temperature brake grease to the shims where they come in contact with the caliper.

Several aftermarket manufacturers also sell disc quieting products that act to glue the brake pad backing plate to the caliper surface. Use these products ONLY if your vehicle was designed without noise reduction shims. Do NOT apply these products to noise reduction shims. See this quote from the April ’15 issue of Motor Magazine.

“Disc brake quiet is a gluelike product that’s marketed by several manufacturers. Its purpose is to stop brake squeal and noise by dampening vibration at the caliper/brake pad interface. Manufacturers also claim it provides a tighter fit, allows for easier disassembly and protects against corrosion. The important thing to be aware of is that this product contains an elastomeric polymer and is designed for use with brake pads that do not have antisqueal pad shims. Use of this product with pad shims may actually be detrimental.”
— Karl Seyfert Motor Magazine, April 2015

Step 4: Clean the caliper slide pins/bolts and lube with fresh high temp brake grease

©, 2015 Rick Muscoplat

Posted on by Rick Muscoplat

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