What Causes Caliper Bolts to Break?

The brake caliper bolt, also known as the caliper bracket bolt or the caliper mounting bolt, secures the brake calipers to the steering knuckle brackets. It’s a bad idea to drive with broken caliper bolts because they compromise your ride’s ability to slow down.

But what exactly causes caliper bolts to break in the first place?

Common Causes of Brake Caliper Bolt Problems

Caliper bolts are crucial to the braking system, so there’s a lot of merit in knowing what causes them to break down. You can prevent or avoid them to prolong your bolt’s lifespan. Here are some of the most common causes of broken caliper bolts.

Bad Brake Pads

Brake pads press against the rotor to generate friction that slows the vehicle down. If the pads wear down, they won’t make as much contact with the rotor, making it difficult for them to create friction.

When this happens, the caliper stiffens, causing damage to the caliper bolts that keep the mechanism in place. If this problem is left unaddressed for too long, your vehicle’s caliper bolts might break entirely.

Caliper Bolts Are Too Loose or Too Tight

Every vehicle has a unique torque specification for caliper bolts detailed in the owner’s manual.

When a caliper bolt is too loose, your vehicle will vibrate and shake roughly when braking. On the other hand, when a caliper bolt is too tight, it gets extra strain, making it more brittle and likely to break apart. It can also misalign, becoming more prone to breakage.

Corrosion

Corrosion is inevitable for some parts of the braking system. The heat-up and cool-down cycles the system goes through regularly can cause the brake calipers to corrode. The issue can also affect their bolts.

On average, brake calipers and their components should last roughly 100,000 miles or around 10 years. Of course, these numbers could change depending on your driving habits. Abusing the brakes or driving your vehicle through challenging terrain and conditions can shorten the lifespan of your caliper bolts.

Insufficient Lubrication

The braking system needs regular lubrication to prevent excessive friction in the parts that rub against each other. Besides low brake fluid levels, one of the other reasons insufficient lubrication occurs is due to a torn-out rain boot.

Every bolt has a rubber component called a rain boot that maintains the grease and keeps the bolt lubricated. If this rain boot breaks, the bolt that secures the caliper to the bracket becomes firm and more likely to break.

Stuck Brake Calipers

Brake calipers can get stuck when they corrode or when dirt and other debris build up inside them. These issues cause the caliper bolts to accumulate obstructive gunk that could lock them in place. While locked, the brakes could remain engaged even when the brake pedal isn’t being pressed due to clogged components.

This is also brought about by the slide or the piston in the caliper getting stuck. Brakes that are constantly engaged will place extra strain on the caliper bolts. This added stress makes the bolts more prone to damage and eventual breakage.

Unaligned or Stuck Piston

Brake calipers need pistons to apply pressure to the brake pads, pushing them forward to create the friction necessary to stop the vehicle.

When the pistons fail to align with the rest of the calipers or brake pads, it can get stuck. The piston getting stuck due to dirt and debris in the caliper can cause similar issues.

If you’re replacing your brake calipers, make sure they’re installed correctly and that there isn’t any gunk preventing the piston from moving. Make sure the replacements are compatible with your vehicle to ensure alignment.

You can also check out these videos for more tips on how to replace your brake caliper:

Worn Brake Hose

If a brake hose is damaged, your vehicle’s brake fluid might fail to cycle the fluid back to the master cylinder. The brakes might feel stiffer and less responsive as a result. If left unresolved for too long, the brake calipers’ condition will worsen to the point of breaking.

Symptoms of Damaged Caliper Bolts

Here are some of the most prominent signs and symptoms of damaged caliper bolts to watch out for.

Brake Fluid Leak

If the master cylinder is constantly leaking, it might be worth investigating the caliper bolts to see if they’re screwed on properly or if they’re damaged.

Clunky Grinding Noises

Harsh grinding noises could indicate that your vehicle’s brake cushions are wearing out. The worn brake cushions might be putting a lot of strain on the caliper bolts.

Soft Brake Pedal

Brakes should be responsive, not floaty. If your brake pedal feels soft when you step on it, there’s a chance your brake calipers are damaged. Floaty brake pedals mean you’ll need to exert more force to slow the vehicle down.

Unevenly Worn Brake Pads

If one brake pad wears down faster than the other, or if both brake pads tend to erode quicker than usual, you might be dealing with a clogged or damaged brake caliper. This issue can be due to bad caliper bolts or bolts with damaged rain boots.

Vehicle Pulls to One Side

If your vehicle veers to one side when you hit the brakes, it might be because only one of the brake calipers is doing its job properly. It might be a good idea to check out the brake calipers and the bolts used to attach them to the bracket.