Mechanics CornerTips

How To Fix Squeaky Car Brakes – Why Do My Brakes Squeal?

Brake disc and pads closeup

Got a headache from squeaky car brakes? If like me, you can’t even stand that plastic on plastic dashboard squeak then having any kind of brake noise can immediately cause fury. Here are a few common types of noises that come from the brakes and tips on how to fix them.

 

  1. Vibration of the brake pads (squealing)

One of the most common causes for brake squeal is vibrating pads. The first thing to check is the anti-rattle springs and also make sure the anti-squeal shims are located correctly. Then add some copper grease in-between the rear of the pads and the piston whilst trying to avoid getting any on the piston seals, as this can cause the rubber to swell that can eventually lead to leaking seals.

 

2. Seized caliper slider/guide pins (binding, scraping and squealing)

The caliper slider pins are a crucial part of the braking system, the idea of these is so even pressure is applied from the pads to the disc. If one pin is seized, uneven wear will occur on one end of the pad. If both pins are seized the pads could effectively be stuck against the rotor disc because the pads cannot fully retract from the disc (much in the same way to when the caliper piston has seized slightly). When new pads are installed the caliper guide pins on floating calipers should always be cleaned in solvent, then new grease should be applied. This grease is under extreme heat so always use a high temperature type of grease.

 

2. Rust on the rotors after a lengthy stationary period (scraping and squealing)

Ever noticed your brake discs looking rusty in the morning? This is due to moisture from rain, condensation or high humidity which causes a formation of rust to appear on the rotors. It’s perfectly normal and nothing to worry about, however if the vehicles left stand-still for a long amount of time, large amounts of rust can build up on the leading edges of the brake pads. This build up can cause squealing, we recommend to use brake cleaner to diagnose if the squealing is from a build up of rust / brake dust first. If you still find they’re still squeaking try some of the other methods on this page.

 

3. Budget branded pads (squealing)

Cheap and ‘cheerful’ semi-metallic pads may look good from the outset, but in the composite resin lies the very reason why they’re cheaper. These brake pads are comprised of metal shavings, which include copper, steel, graphite, and brass bonded with resin. Brake pad brands with a higher amount of metal content in them than original equipment can cause various noises after some wear. If you think your brake noises are because of this, try out some pads that are advertised as ‘organic’. They’re typically far quieter and are in the form of cellulose, aramid, PAN, and sintered glass. They tend to have a shorter lifespan but the gains in performance are far better.

 

 4. Worn out brake pads – The pad wear indicator (scraping)

Scraping noises can occur when the pad wear indicator tabs (which are made from hardened steel) start scraping on the rotor disc. They’re used as a guide for general pad wear and are attached to the pads in different ways depending on the brand. If you notice this type of sound, get those brake pads checked ASAP.

 




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