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Lexus IS: Why Do My Brakes Squeak?

There are a few reasons as to why your breaking system is squeaking. Use this guide to locate the source of the squeak and learn how to fix it.

By James Karuga - November 20, 2014

This article applies to the Lexus IS (2005-2014).

Squeaking brakes are not just a source of annoyance; they're also the first major sign that the braking system needs to be examined. Squeaks happen for a few reasons. The first and most likely cause is worn down brake pads. Cold conditions will also make brakes squeal, as will driving a Lexus IS that has been static for a while. The good news is that diagnosing and fixing most causes of brake squeal can be done at home. It's worth it to visit the mechanic for help if they're troublesome. This guide provides some causes of brake squeaks and their solutions, including the basic DIY fixes available.

Step 1 - Are the brake pads or insulation shims worn out?

Every new vehicle comes with insulation shims placed against the steel side of the pad to insulate it from the brake caliper. The shims eventually wear out due to braking. When changing brake pads, don't forget to replace the shims with new ones and to coat them with anti-squeal grease. Incorrect brake pads will also squeak and make noise as they move around in the caliper. Neglecting to change the pads can result in long term wear on the brake rotors.

Figure 1. The pad on the left was removed when it started squealing.

Step 2 - Are the rotors rusty?

Those living in cold, wet, or snowy locations are likely familiar with the sight of rust on brake rotors. That accumulated coat of rust causes annoying squeaks. However, using the brakes as you drive the Lexus IS wears off the small rust layer and restores the brakes to normal quietness.

Figure 2. This rotor has accumulated rust.

Step 3 - Are the anti-rattle clips broken?

Brake pads are held in place on the caliper by pad stays. An anti-rattle clip secures the pad to stop it from vibrating while braking. If clips are worn out, the pad vibration will result in a squeak. When that happens, have the clips replaced and the squeal and rattle will be history. Most anti-rattle clips for Lexus IS vehicles cost less than $50.

Figure 3. This anti-rattle clip is intact.

Step 4 - Are the rotors worn out?

An uneven rotor surface causes the brake pads to ride roughly on the rotor. Uneven rotors will squeal when braking lightly, but they'll also shudder when braking heavily. Uneven rotors can also damage the anti-rattle clips and caliper pins if left untouched. The rotors can be smoothed if they're thick enough. Once the rotor is smoothed, the pads will glide seamlessly on the surface.

Figure 4. Check the rotors for extensive wear.

Pro Tip

Generally, it's best to just replace the rotors instead of resurfacing them. Resurfacing removes material which makes them more prone to cracks and breaking.

Featured Video: Why Do My Brakes Squeak in Lexus IS?

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