Brake Caliper

The Definitive Guide

Brake CaliperA brake caliper forms the heart of a disc brake system. It enables the braking action to happen, something that enhances safety and drivability.

With vehicle manufacturers today preferring disc to drum brakes, these components are bound to be more common than before. But how do brake calipers work and what is their function in an automobile. Also, how can you tell a faulty one to carry out repairs or replacement?

That is why we compiled this brake caliper guide; to answer the questions you might have concerning this essential auto part. In the guide is information about the working principle of the brake caliper, its purpose in the braking system of a vehicle, and the different types of these calipers. You will also learn about how to troubleshoot a brake caliper. And if you find it damaged, how to fix or replace it. Read on.

Chapter 1

What is a Brake Caliper

automotive-brake-caliper-1

What is a Brake Caliper?

 

A brake caliper is the part in a vehicle that pushes the brake pads onto the rotor when you apply the brakes. It’s a hydraulic actuator, which means it uses fluid pressure to cause movement.

Usually a clamp-like assembly, a brake caliper partially frames the brake rotor. It forms the hydraulic output of a disc brake system and houses the necessary parts such as the pistons and brake pads.

Brake calipers can be said to be the heart of the braking systems of vehicles that use disc brakes. Because disc brakes are the most common, you will find brake calipers in virtually every modern automobile.

Brake calipers mainly come in two types, as we shall see later. The two caliper types operate in a way that’s only slightly different- the basic working principle and structure remain the same.

Each caliper type has its up and downsides, and a car will have one or the other depending on the vehicle application. The type of brake caliper used on a vehicle also depends on the model or make.

What purpose do these components serve?

 

Brake Caliper Function

car caliperIn every motor vehicle, there’s the motion of the wheels that needs to be controlled. This is usually done by the use of brakes, which can be either drum or disc (rotor) brakes. Brake calipers form part of a disc brake system, which also happens to be the most common in today’s automotive.

Brake calipers have two functions in a motor vehicle:

One, they house and guide the brake pads. That ensures every time you apply the brakes, the brake pads are in the right position to move onto the rotor. Brake calipers usually feature a design that ensures compensation for the wear on the brake pads. As a result, the pads are always within the right distance from the rotor for efficient and reliable braking.

Two, brake calipers provide the hydraulic actuation that converts brake fluid pressure into mechanical movement. It’s this movement that enables the braking action in motor vehicles. We can, therefore, say that a brake caliper is a stoppage device that helps to ensure safe driving. Without it, your disc brake system would be of no use.

How do brake calipers work? Let’s see.

 

Brake Caliper Operation

Brake calipers play a significant role in slowing down or stopping a moving motor vehicle. But how does the assembly achieve that when what you apply on the foot pedal is only a slight force? The operating principle of this component is fairly simple and straightforward. This is how a brake caliper works:

Image source: wikipedia.com

  • When you apply the brakes, a piston moves and produces pressure on the brake fluid in the master cylinder. This pressure transmits to the brake lines, through the hoses, and to the brake caliper piston or pistons
  • The fluid pressure causes the caliper pistons to move out of their bore. As a result, the brake pads push forward to make contact with the rotor or brake disc
  • The squeezing action of the brake pads on the brake rotor causes immense friction that opposes the motion of its spin
  • Depending on the amount and duration of pressure at the foot pedal, the brake rotor either slows down or stops altogether
  • The brake disc (rotor) attaches to the wheel, so the action of the calipers on either side of the axle causes the car to stop or decelerate
  • As soon as you release the brake pedal, the hydraulic fluid returns into the master cylinder and out of the brake caliper pistons.
  • The resulting drop in pressure causes the pistons to move back and the brake pads to release the rotor. The piston rubber seals pull the pistons back into their bores.
  • The caliper is then ready for another actuation to stop or slow down the spin of the brake rotor and, therefore, the moving vehicle.

This YouTube video explains the working of a brake caliper

When you step on the brake pedal, fluid pressure transmits equally in all the brake lines and hoses. That means the brake caliper pistons on every wheel experience the same amount force. The result is balanced braking that ensures safety.

Brake calipers will also have a varying number of pistons. It can be a single piston for the lighter automobile or several for the heavy trucks that require higher stoppage power. The number usually depends on caliper type, application, and to some extent, design.

 

Brake Caliper Location

Where Do You Find Brake Calipers? Well, brake Caliper Location usually depends on the make and application of a vehicle. Generally, you will find these assemblies at the wheels and on the front axle. The calipers typically attach to a car’s steering knuckles.

Brake calipers mount on the steering knuckle in two different ways. It can be directly, supported by bolts and pins. Or, it can be with the help of a mounting bracket that holds the assembly onto the knuckle.

Though not often, there are vehicles that have brake calipers on both the front and rear axles. These are the cars that utilize disc brakes on all the wheels. When brake calipers are installed on the rear wheels, they are usually mounted on the rear spindles by means of bolts.

Now, let’s have a look a how a brake caliper looks like.

Disc brake assembly

Source: lesschwab.com

As you can see from the brake caliper diagram, the device looks like a C-clamp and strides the brake rotor. This allows it to squeeze the brake pads on the disc powerfully and with greater precision. Most calipers feature these major parts:

  • The piston(s)- these are what move when pushed by the brake fluid to close the gap between the brake pads and the brake disc. The pistons can be steel, plastic, or even aluminum. They can also be one or several of them
  • Brake pads- the pads press against the brake rotor to cause the frictional force that stops or slows down the spin. Brake pads feature different materials each with own advantages and disadvantages
  • A dust boot- prevents contaminants such as dust and debris from entering the piston cylinder. This is essential since the low position  and open mounting of the caliper subjects it to all sorts of contaminants on the road
  • A Bleeder screw- lets you remove air from the brake lines ( bleed) when replacing the braking fluid or carrying out other caliper servicing tasks
  • Piston rubber seal- serves two purposes: one, it prevents the brake fluid from leaking and two, retracts the piston too its original position when you release the brake pedal

 

Brake Caliper Torque Specs

You may have heard about brake caliper torque specs and how knowledge about them is essential. Also, how even mechanics find it hard to determine the values when installing or servicing brake calipers.Why is that so?Brake calipers are typically identical in construction and working principle. However, there exist some few differences. One of them is in the bolt torque specifications. These are different from one manufacturer to another, and essential when dealing with brake calipers.

When installing a new caliper, it’s always advisable to obtain the exact torque specs to ensure correct tightening pressure. That’s because over-tightening or under-tightening can have bad results.

You can find brake caliper torque specs in the service manual of the specific vehicle. Alternatively, you can contact the manufacturer to obtain the information from them. It’s much better than having to guess the values.

Chapter 2

Brake Caliper Type

2-brake-caliper-types

Brake calipers come in two major types: fixed and floating.

How can you tell one from the other? The calipers mostly differ in terms of design, mounting, and operation.

Let’s look at each type in detail.

disc-brake-in-the-car

Source: Wikimedia Commons

 

Fixed Calipers

These are often large, heavy, and powerful. As the name implies, a fixed caliper doesn’t move but bolts solidly to the caliper bracket. During the braking action, the piston or pistons on both sides move with equal force to clamp on the rotor.

Fixed calipers feature pistons on either side of the brake disc. Because they come in pairs, the number of pistons range from 2, 4, to 6. Some will even have a total of 8 pistons. However, that is when immense braking power is required such in high-speed or heavy vehicles.

 

Floating Calipers

Floating calipers are compact, lightweight, and not as powerful. They don’t mount rigidly and instead, slide freely on lubricated pins and bushings. Floating calipers come with either one or two pistons. Both pistons are located on the inboard side of the brake disc.

A floating caliper uses a slightly different method to move brake pads to the rotor. Pistons and brake fluid are involved though, just like in the fixed caliper. This is what happens.

When you step on the brake pedal, the fluid pressure moves the piston(s) which then squeezes the inboard brake pad against the brake disc. Now, the rotor is fixed and the caliper free to move.

As a result, the force of the piston pressing against the rotor causes the caliper to move backwards. This makes the brake pad on the other side to move towards the brake disc. The clamping action of the two pads then slows down the disc.

The sliding brake caliper is a variant of the floating caliper type. It works in the same way, the only difference being in the mounting. Instead of having pins and bushings to

Each brake caliper types comes with its own pros and cons

Fixed calipers feature multiple pistons. That makes them more powerful than the floating type, and suitable when a lot of power is required to stop a vehicle. They’re often used in racing cars, high-speed bikes, and heavy vehicles that need a lot of force to stop.

When it comes to braking force distribution, fixed calipers perform the best. The multiple pistons on a single caliper also allow for brakes with longer pads. Another advantage of fixed calipers is the feel they produce at the brake pedal. They produce a quick,  firm and powerful grip of the rotor, which transmits all the way to the driver’s foot.

Fixed calipers are not without disadvantages. They have more than one piston, which makes them heavier than the floating type. They are also usually large, especially when the number of pistons exceeds four.

heavyduty-caliper

Source: semashow.com

Because fixed calipers require precision machining, they are more expensive to make. The many pistons also contribute to the increased manufacturing costs. Another downside of these caliper types is their reduced tolerance to the rotor imperfections. They are rigidly mounted, which makes them to pulsate to the rotor runout.

Floating calipers are the most common in today’s motor vehicle. There are many reasons for this. First, floating calipers usually feature not more than 2 pistons which makes them compact and lightweight. They are, therefore, suitable when not much braking power is needed such as in everyday cars, passenger vehicles, or light trucks.

The fewer parts (pistons) also makes floating calipers inexpensive and easy to mass produce. Unlike the fixed caliper, this type tolerates rotor imperfections or runout better. That’s because it moves freely and cancels out the resulting vibrations.

The disadvantage of the floating caliper include the lower braking power that makes them not ideal for certain applications. For example, this type of caliper cannot be used in the braking systems of heavy motor vehicles.

These caliper types are also prone to sticking when the pins corrode to make sliding difficult. Floating calipers can cause uneven wear on the brake pads. That happens due to the almost inevitable delayed movement of the outboard pad when braking.

 

Fixed Caliper Vs Floating Caliper

 

Brake Caliper Design Differences

 

Brake calipers can be other monobloc or two-piece.

Monobloc calipers, as the name hints, are cast from a one-piece metal. They are stronger, and can last a long time. The strength and durability come at a price, though, because the calipers are expensive to manufacture.

Two-piece calipers, on the other hand, are made from two metal pieces that are joined by means of bolts. These caliper types are not as strong as the monobloc caliper. However, they are easier and less costly to make.

 

Construction Material Differences

 

Brake calipers can be either cast iron or aluminum. The calipers in the older vehicles are mostly cast iron while newer ones feature aluminum calipers. There are the advantages and disadvantages of each construction material.

Cast iron brake calipers are sturdy, less costly to make and better at dissipating heat. Those that are made from aluminum are loved for being lightweight.

When it comes to the caliper pistons, the materials to make them are more varied. The pistons can be chrome plated steel, plastic or aluminum.

caliper-pistons

Source: ftoaustralia.com

Using aluminum to make caliper pistons reduces their weight. However, aluminum is prone to corroding. It also transmits heat to the braking fluid easily, which can be a disadvantage.

Steel pistons are stronger, and chrome plating them minimizes the chances or rust or any other form of corrosion. But steel transmits heat easily, and can cause hydraulic fluid boil and other problems.

Plastic pistons are lightweight and corrosion-resistant. They don’t conduct heat to cause fluid boil or brake fade. But the plastic can absorb moisture and swell up, causing the pistons to stick and present braking problems. Steel and aluminum pistons can experience sticking problem too, but only when the material has corroded severely.

Chapter 3

When to Replace Brake Caliper

when-to-replace-brake-caliper

A newly installed brake caliper

Source: flickr.com

Brake calipers are built to be sturdy, hard-wearing, and resistant to various forms of damage. However, they eventually give in to the effects of time and show signs of aging. If the calipers are not replaced or rebuilt on time, wear and damage can significantly affect braking.

To ensure safe driving, reliable brakes are absolutely necessary. That means ensuring every part of the braking system is working perfectly. Among the components to keep an eye on are the brake calipers. You need to know when to install new ones.

 

How long do brake calipers last and how can you tell when it’s time to replace or rebuild them?

It’s not easy to recommend exact timelines. The reason?

Brake calipers wear out differently from one vehicle to another. That’s because the rate of wear depends on your driving habits, driving conditions, and the climate of your place. The wear rate also depends on caliper type, design, and quality.

A worn out brake caliper

Source: flickr.com

Here is what happens:

Too much braking causes intense heat to generate at the calipers, the brake pads, and the brake disc. Although the heat quickly dissipates into the air, the constant heating and cooling can have a detrimental effect on the caliper.

Rough road conditions compel you to use the brakes too often. That affects not only the pads and the rotor but also the calipers, accelerating its wear. Such roads may also produce other corrosive elements such as dust and cause caliper wear to show up too soon

Moisture is also a culprit when it comes to the rate of wear of the calipers. It causes the pistons, the piston bore, the caliper body, and other parts to corrode and wear out quickly. And if it’s floating calipers that your car uses, moisture can cause them to rust and the caliper to stick.

Floating calipers are more prone to damage or wear. They feature more moving parts which can fail at any time. Besides the pistons that may freeze from corrosion, there are slides and pins that easily rust and halt the sliding action.

That said, brake calipers in a typical modern car can last 100,000 miles or more. In terms of time, that could translate to around 10 years of normal driving. But as we have seen, that varies and depends on different factors.

 

How do you know when the calipers need to be changed?

It’s advisable to check the condition of the calipers from time to time. That can be whenever you inspect other brake parts such as the pads and rotors. You can also take advantage of the times when other parts of the vehicle. An example is when working on the wheel hubs, axles, and related components.

 

A rusty brake caliper

A rusty brake caliper

A simple observation can reveal wear and damage, and give you an idea of its extent. These include signs of corrosion, braking fluid leaks as a result of worn piston seals, corroded pistons that could stick in their bores and more.

If yours are floating calipers, you may need to examine the slides, bushings, pins, and the pistons. Fixed calipers do not have many moving parts and are easier to maintain. You would still have to inspect them for wear still.

Should you find any signs of damage (which we will learn about later) it’s necessary to take action. The last thing you want is a faulty braking system due to a worn caliper.

Corroded pins or slides may require a lubricant or if too much damaged, new ones. For that, you may choose to have the entire caliper replaced, especially if the other parts are badly worn out as well.

 

Corroded caliper guide pin

Source: safebraking.com

You may also opt to rebuild the caliper. A brake caliper rebuild comes with its advantages and disadvantages of course. You would need to weigh between the two and select the option that suits you the best.

 

Do Brake Calipers Need to Be Replaced in Pairs?

This is a question that many car owners ask. Your mechanic may suggest that you install new calipers on either side of the front or back wheels. And that even when it’s evident that only one of the calipers is faulty. Is it the right thing to do?

The answer is, it depends.

Generally, you only replace the damaged caliper. Doing so makes economic sense, plus there may be no need to change a component that has not failed or shown signs of doing so soon.

But that is not always the case. There are several instances where you would need to replace the caliper on the other side as well. They include:

  • If the other caliper is nearing its end of life. While it may look to be working perfectly, chances are that it’s not currently as powerful as the new one. That different braking forces could cause brake pulls, something you wouldn’t want to experience. It could also result in uneven pad wear and inconsistent braking.
  • If the other caliper shows signs of wear or damage, it may not be long before you need to replace it, too. Besides, the damage could cause sticking of the pistons or slides and your car pulling to one side during braking. It could also be a case of worn pistons that quickly worsen to cause fluid leaks and lost braking power on one side of your car.
  • If the new one is made from a different material or design- while not likely to happen, the new caliper could be sightly different in certain specifications. That could cause braking and pad wear that is not uniform. Also, brake pulls when you step on the pedal or lift your foot off.

To sum it up, the time to replace brake calipers depends on many factors. Because driving conditions and habits are different, there’s not really a set time or lifespan of a brake caliper. That means you change them when they start to operate inefficiently.

Replacing only one caliper may not affect braking too much. However, if the two calipers were installed on the same day, changing them at the same time is more advisable. Why? The lifespan of the pair is bound to be almost similar, and it may not be long before the other one fails.

Chapter 4

Bad Brake Caliper Syptoms

 

bad-brake-caliper-syptoms

Brake calipers are crucial components of the disc brake systems.

Their failure can mean a car that won’t stop normally, which is not desirable when cruising down a road at high speed.

Apart from checking the calipers for damage from time to time, knowing the signs to look out for is highly essential.

It helps to ensure safe braking and comfortable driving.

 

What are the Symptoms of a Bad Brake Caliper?

They are several and include the following:

 

1. Brake Pull

Have you ever felt your car sway to one side when you stepped on or released the brake pedal?  That’s known as a brake pull. It happens when the wheel on one side rotates faster than the other during braking. Brake pulling is common when the brake caliper on one side of the wheel axle doesn’t work. There are different reasons for that.

The main cause for that is a brake caliper sticking and failing to move toward or away from the brake disc. The piston could have pressed against the rotor on applying the brakes, but failed to retract on releasing the pedal. A brake or vehicle pull can also result from a piston that freezes before it squeezes the brake disc.

There are different causes for a stuck caliper.  It could be debris that found its way into the cylinder to cause seizing. Or, it could be a situation where the caliper or piston corrodes from the action of moisture and other elements. Both will cause the piston to wear and its movement to become less efficient. The heat that braking generates could also cause a brake caliper to stick.

 

2. Brakes that are Less Powerful

Reduced braking force means a brake caliper not working at its optimum. Several components or mechanisms could be the culprit in such situations. There could be a leak in the brake lines or at the pistons on the caliper. A leak lowers the fluid pressure. As a result, the force with which the piston pushes the brake pads reduces.

If one of the pistons freezes in its bore from the effects of grime, corrosion or debris, a problem arises. The piston cannot move to the brake pad powerfully. The clamping force of the calipers reduces, and you feel the results when driving the vehicle.

You can easily tell if the brakes are not as powerful as before. If you need more effort to stop the car, it could mean you have lost some fluid pressure. It could also be a piston that’s not working properly. You may want to take your vehicle to a professional so they can correct the problem.

Or if possible, you can choose to check the calipers yourself. If they are badly damaged, you may need to replace them to restore the braking efficiency. The right braking power is essential. If the vehicle is heavy, a slight loss of the force to stop it could cause dangerous situations.

 

3. Uneven Wear of the Brake Pads

Under normal conditions, the brake pads should wear uniformly. But sometimes that doesn’t happen, and you may notice one side thinner than the other. In such cases, a bad caliper is often the cause. The caliper assembly holds the mechanism the presses the pads against the brake disc, and uneven wear can mean a caliper malfunction.

Although uneven brake pad wearing is one of the signs of caliper problems, self-diagnosis of the imperfection can be difficult. It requires a professional to inspect the pads to troubleshoot this symptom. That’s because there are other causes besides a bad caliper.

 

4. Squealing Noise

This noise occurs when you have not pressed the brake pedal. It’s different from the noise that indicates worn out brake pads, which comes up only when the brakes are engaged. The noise indicates a brake caliper that has seized. Brake caliper sticking noise may sound like metal rubbing against metal. It can also be a screech that’s high-pitched.

Brakes shouldn’t produce sounds regardless of whether you’ve stepped in the pedal or not. Should that happen, it’s advisable to have them examined as soon as you can. Often, the problem of a brake caliper sticking while driving can be remedied easily- either through repairs or caliper replacement.

 

5. Clunking Noise

In the worst of situations, a brake caliper bracket can break free from its holding bracket.  This can render the caliper unusable and present danger to the other vehicle components. Although rare to have a snapped caliper, it can- and does- happen.

A broken caliper will not stop your vehicle and there’s no need to continue driving if it occurs while on the road. Always listen out to a clunking sound or thud that occurs when you apply the brakes. It’s often sign that the caliper no longer securely bolts to the bracket.

Pull up, and have the problem fixed before proceeding. You don’t want to drive with one side of your braking system not working. Apart from the reduced braking force, it can mean dangerous sways whenever you step on the brake pedal.

 

6. Leaking Braking Fluid

The braking fluid reaching the caliper is always held in by rubber seals and boots. Over time, these seals weaken from the action of debris, exposure to heat, and other elements. Eventually, a leak or leaks develop and decreases the braking pressure.Pressing on the brake pedal then doesn’t produce enough force to clamp the rotor tightly, and your car or truck takes longer to stop. That’s a dangerous situation that requires immediate action, usually by referring the problem to a professional.

Leaking Braking Fluid Piston

Source: jeeps.com

You can spot a leak by observing the areas along the brake lines and hoses. In the case of a faulty brake caliper, you can look at the area just beneath the caliper position at the wheel.  If there’s a spot or puddle of a liquid that’s oily, the piston seals are broken and leaking of brake fluid. The smell of burnt rubber can also indicate a leak.

 

7. Brakes that Feel Like they Are Engaged All the Time

A simple sign of this caliper problem is the feeling that the vehicle you’re driving struggles to move forward. You might also feel that the speed keeps reducing drastically than normal, or that the parking brake is engaged when it isn’t.

All these problems indicate a stuck caliper. The rubber seal that pulls the piston(s) back may be old and no longer effective. Or, grime could be halting the pistons and causing the brake pads to remain pressed against the rotor.

If it’s a floating caliper, we could be talking about slides that have lost lubrication or corroded badly to prevent free movement. Should you notice these sticking brake caliper symptoms, it means the assembly needs prompt checking. That would enable you to carry out repairs or replace the whole assembly.

 

8. Dashboard Brake Light

brake-warn-lightA dashboard brake light can come on for various reasons, one of them being leaking of the brake fluid. Because leaking can occur at the caliper piston from a worn out rubber seal, the light can be a sign of failed caliper.

A skilled mechanic can check for this caliper problem to rule out any other cause for the brake light. Alternatively, you can check the piston leak yourself. As we saw earlier, an oily spot near where the caliper is situated can signal a broken piston seal.

Chapter 5

Brake Caliper Diagnosis and Troubleshooting

brake-caliper-troubleshooting-diagnosis

troubleshooting-the-different-caliper-parts

Source: ricksfreeautorepairadvice.com

Checking and maintaining brake calipers isn’t reserved for the mechanics only. Some of the diagnostic or troubleshooting tasks are simple, and you can conduct them on your own.

Check out this YouTube video

To find what the problem is with a caliper, you need a few skills. These include knowing how to check brake caliper operation. Not only that but also how to do it like an expert. That’s what this chapter is all about.

Let’s start by looking at the major issues and caliper parts that require checking. They include:

Brake caliper sticking

Brake caliper assembly- the sliding pins and bushings, pistons, and mounting brackets.

Now, a look at how to troubleshoot each problem.

 

Brake Caliper Sticking

Reasons for a sticking caliper are;

  • Corroded caliper assembly as a result of moisture, debris, salts and other elements
  • A contaminated braking fluid that causes the pistons  and other inner surfaces to corrode
  • Lost lubrication on the sliding pins that hinders caliper movement
  • An inefficient master braking cylinder that results in low braking pressure
  • Corroded piston or pistons that cause sticking in the bore
  • Not using a vehicle for long and the brake pads sticking to the rotor as a result

 

a-neglected-brake-caliper-is-prone-to-sticking

Source: alloyandgrit.com

 

How do You Detect Caliper Sticking?

The signs of a frozen caliper include;

  • A vehicle that cannot maintain speed for long
  • Brakes not pressing or releasing smoothly when you place your foot on and off the brake pedal
  • A car vehicle that pulls sideways on applying the brakes.
  • Extreme heat at the wheels where you find the calipers
  • The smell of burning rubber

To locate the sticking caliper, place the hand next to each wheel without making any physical contact with it. If warm air reaches your hand to indicate a hot wheel, that’s where the caliper in question is situated.

Try to rotate the wheel using your hand. If it doesn’t spin freely, you may need to take it out and examine the brake pads and the caliper. If the pads show uneven wear, a sticking caliper could be the fault. You can also observe the rotor to see if it has heat marks on the surface.

If a stuck caliper is not repaired or changed, it can cause overheating. Also quick and irregular pad and rotor wear, reduced acceleration, and a stressed transmission. In general, a sticking caliper reduces the effectiveness and lifespan of the brakes.

 

How to Fix a Sticking Brake Caliper

sticking-brake-caliper

You can opt to either change the affected part or the whole assembly. It depends on your budget and the condition of the other parts of the caliper. That’s why a careful examination of the entire device is essential and highly advised.

Also, you may want to use the DIY approach or seek a mechanic’s help. Whichever method you choose, here is the procedure to service your car’s brake calipers.

To inspect the caliper assembly, you would need to remove.

  • Using a wrench loosen the nuts on the wheel
  • Next, jack up the body of the vehicle
  • Remove the wheel to expose the caliper
  • Remove and plug the brake hose
  • Unbolt the caliper and take out the brake pads.

 

Checking the Brake Caliper Assembly

You may need to determine what caliper type your car uses first.

brake-caliper-assembly-diagramIf it’s the floating type, the pistons will be located on one side only. The pistons should also number not more than two. Additionally, you’ll notice the slide pins, which also attach the caliper assembly to the mounting plate.

A fixed caliper features pistons on either side and which can be as few as two to as many as eight. There are no slide pins, and the assembly mounts solidly on the caliper bracket at the steering knuckle.

Next, disassemble the caliper. The process for this differs from one vehicle type or manufacturer to another. If your car’s manual is available, it’s advisable that you consult it.

Here are the steps to inspect the assembly

  • Check the brake pads for wear and determine if it’s uniform. Also, if the pads are too worn and require to be replaced
  • Examine the sliding pins. These allow the caliper to move back and forth, and it’s essential to have them adequately lubricated. If there’s isn’t enough lubricant, apply one that’s high-temperature and appropriate for the use. If there are signs of corrosion on the bushings and pins, you may use a brush to or age to clean it
  • Inspect the brake caliper pistons. Check for signs of corrosion and other forms of wear. Also if the rubber seals are broken or too worn to be of any use if the caliper is used for a little longer.
  • Lastly, check the mounting bracket for wear and damage. A broken caliper can cause noise when driving. Loose brake caliper noise, usually occurs whenever you apply the brakes, and you should notice that easily.

If the brake caliper shows signs of severe wear or corrosion, it would be better if you replaced it. That’s because fixing specific parts doesn’t guarantee a correctly working caliper for long. You might find yourself having to carry out another repair soon.

While repairs might seem less costly, they’re not in the long run. Besides, not many mechanics advocate for that. And if you’re doing it yourself, you will find installing a new caliper more preferable. It’s easier, quicker, and guarantees better results.

After you’re through with inspecting and fixing or replacing a brake caliper, there’s the need to do a test. Drive the car for a few minutes and get a feel of the brake pedal. It should provide all the signs of a firm, efficient and powerful braking system.

The brake pedal should not depress fully but should leave a slight clearance. It should also feel firm and not spongy. If you notice otherwise, you may need to have a professional inspect the caliper. Ensure too, that there are no strange sounds such as bad brake caliper noise when you depress the brake pedal.

Chapter 6

Brake Caliper Replacement

brake-calipers-replacement

a-car-brake-caliper-need-to-be-replacedA brake caliper that has served its life needs to be changed

Brake calipers, although made to be strong, cannot last forever. You eventually have to replace them. When that time comes, the dilemma is often whether to do it yourself or involve a professional.

The DIY approach is a popular option-and for various reasons. The cost to change a worn brake caliper can be quite high, running into a hundred dollars or more. If you have a pair to replace (and which is often the case), it can mean having to part with a lot of money.

That’s why many car owners choose to carry out the installation themselves. It lowers the brake caliper replacement cost plus it provides the chance to learn a skill. The only expense then is the amount you spend to buy the caliper.

Although the procedure to replace a brake caliper may look intimidating, it shouldn’t. The task is straightforward and mostly doesn’t require any prior experience. Should you decide to go the DIY way, here is the process to follow.

 

How to Replace a Brake Caliper

You will need these installation tools. A car jack, wrench, screwdrivers, torque wrench, socket set, pliers, drop light, braking fluid, gloves and a pair of googles. Ensure, too, that you have your car’s service manual with you for reference purposes.

 

15 Steps to replace a brake caliper:

  1. Loosen the wheel nuts but not entirely.
  2. Lift the vehicle body using the jack, but safely.
  3. Now, loosen the nuts fully and take out the lugs and bolts.
  4. Remove the wheel to enable access of the brake caliper. You need enough clearance to make the task easier.
  5. Push the caliper piston away and into its bore. You can use a C-clamp for that or any other tool that’s designed specifically for this job.
  6. Position an oil pan to hold the brake fluid. Next, remove the hose that brings brake fluid to the caliper. Plug the hose using a rubber plug.
  7. Using a wrench, loosen up the caliper then remove the bolts that mount it.
  8. Lift the caliper until it no longer covers the rotor and then simply slide it off.
  9. Remove the brake pads, taking care not to drop them. Check for and clean any corroded surfaces.
  10. Insert the brake pads into the new brake caliper assembly.
  11. Place the new caliper on its mount and over the rotor as necessary.
  12. Bolt it up, taking great care not to under torque or over torque it. Under tightening the bolts could result in a loose brake caliper that doesn’t produce reliable braking. Overtightening can cause breakages.
  13. Next, attach the brake hose to the caliper.
  14. Bleed the brakes until all air leaves and the pedal feels firm.
  15. Return the wheel and reattach the tire.

This video takes you through the procedure to replace a brake caliper

Your new brake caliper is now ready to start working. Test it by driving around to ensure firm braking. If you cannot achieve proper braking power, there’s a step in the process that didn’t go well. Get the help of a mechanic.

 

Brake Caliper Replacement Tips

brake-caliper-replacement-before-and-after

To ensure proper installation of the caliper assembly, here are the tips to follow.

  • Always use new mounting parts if possible. Old material can cause a rattling noise when driving and accelerate the rate of damage to the caliper
  • Ensure proper torque when mounting your new caliper. These are specific to the caliper design and model. You may need to consult the user manual to know the right torque for the caliper you are installing
  • Mounting a caliper the wrong way up is a common mistake. Avoid it by checking and rechecking every step of the caliper replacement process
  • Clean the older parts that don’t need to be replaced before slamming in the new caliper
  • Guide pins allow a floating caliper to slide freely. Lubricate them adequately and with the right caliper grease. Only ensure that you clean them up using a solvent before applying the grease
  • The front and rear brake caliper replacement process may differ in some ways. Ensure you understand the procedure for the caliper you happen to be installing. Mount the assembly appropriately.
  • Brake fluid is corrosive. If by any chance it spills on a painted surface, wash it clean with soapy water
  • Always flush and bleed the brake system after you have performed a caliper installation. Moisture buildup in the line can lead to corroding while air causes the brakes to function less powerfully
  • The instructions by the manufacturer to install a new caliper may differ from the procedure explained here. Should that be the case, it’s more advisable to follow that of the manufacturer

When looking to replace your car’s brake calipers, you might be faced with two options. Some people may advise you to rebuild it instead. While each choice has its up and downsides, a majority of car owners prefer brake caliper replacement to rebuilding.

Why is that so? That forms the subject of our next chapter.

Chapter 7

Brake Caliper Rebuild

When brake calipers age, they lose the ability to provide powerful and reliable braking. It’s at this point that car owners face the inevitable dilemma: whether to buy a new caliper or replace the worn out parts only.

Many motor vehicle owners today choose the installation of new calipers. Mechanic too, seem to offer the same piece of advice; that replacing is better than rebuilding. What are the reasons for that line of thought? Let’s have a look at the options in detail.

brake-caliper-rebuilding

Source: popularmechanics.com

Brake Caliper Rebuilding

Rebuilding a brake caliper involves repairing parts of the assembly. Instead of installing a new unit, you only replace the worn or damaged components. The idea is to restore the caliper’s efficiency by fixing new parts to the old assembly. Often, the brake caliper rebuild kit comes complete with the necessary tools and materials. Even the instruction manual.

 

Brake Caliper Replacement

Replacing a brake caliper, on the other hand, means removing the old assembly entirely. In its place, you mount a new one. Often you replace a brake caliper for different reasons. It can be that the caliper has been on the vehicle for far too long and its performance has dropped. Or, it could be a situation where the caliper doesn’t produce powerful or reliable braking. Safety when driving is then what would compel you to carry out a replacement.

 

Brake Caliper Rebuild Vs Replace

Each option comes with benefits and disadvantages.

Brake caliper rebuild is an inexpensive way to keep your disc brakes going. Usually a DIY process, brake rebuild is worth considering when on a tight budget. It’s also suitable if the caliper that requires repairs isn’t severely damaged. In such situations, replacing would only cause you unnecessary expenses.

Sometimes, a caliper will fail due to slight problems such as sliding pins that have. Because it’s only one part of the whole assembly that’s faulty, you can avoid the extra costs of buying a new caliper assembly. A modern brake caliper rebuild kit usually comes with everything that you need even as a DIYer.

 

a-rebuilt-brake-caliperCaliper rebuild has its disadvantages. First, it’s a messy procedure that involves cleaning corroded or oily surfaces. The process is also tiresome. Besides that, you cannot be sure that the reassembled parts are in their right positions. Also, you could repair a worn out caliper only for it to malfunction soon after.

Brake caliper replacement can cost you a lot. Apart from the cost to purchase the unit, there are the installation costs. That’s if you decide to hire a mechanic for the task. But that may not be a problem since you can always go the DIY way. In any case, the procedure to Mount a new caliper shouldn’t present any challenge.

Replacing a brake caliper instead of rebuilding it comes with several advantages. First, is by far the easiest and cleanest way to restore your brakes. Despite the costs involved, replacing a caliper guarantees you of a better performing device in place. You’re assured of many years more before you need to replace the caliper. It’s more cost effective in the long term.

For one reason or another, you may choose to rebuild the brake caliper on your car instead of installing a new one. Should that happen, this is the procedure to do it.

 

How to Build a Brake Caliper

The caliper parts that may need replacing during a rebuild Source: popularmechanics.comThese are the tools you will need: brake caliper repair kit, jack and axle stands, drip bowl or tray, socket set, brake fluid, and screwdrivers.

The steps to follow:

  1. Loosen the nuts but only slightly then lift the car using the jack and the axle stands. Ensure safety, and don’t depend on the jack alone to prop the car.
  2. Loosen the other bit of the wheel nuts. Remove the wheel so you can work on the caliper unhindered.  Place the drip tray underneath to tap any brake fluid that might spill.
  3. Remove the caliper assembly by loosening and taking out the mounting bolts. Ensure care since you don’t want to damage the brake line. Cap the brake hose with a rubber plug.
  4. Take out the brake pads. These are easy to remove.
  5. Use the brake pedal to pump pressure into the brake system so the pistons can come out. You can also use any other means to remove the piston.
  6. Use the screwdriver to remove the rubber seals. Ensure utmost care during this part of the process. The screwdriver can easily prick the rubber seals and cause brake fluid to leak.
  7. Insert the new pistons together with the new seals. Lube the parts of the caliper adequately and using the right lubricant.
  8. Bleed the braking system to rid it of all the air.
  9. If there are other parts that need changing, carry out the replacement during this step.
  10. Once you’re through, you can now return the caliper to its mounting brackets and test-drive the car

You could also check out this brake caliper rebuild video

https://youtu.be/VxME8Ayk7qY

Conlusion

We have come to the end of this brake caliper guide. Hopefully, you gained valuable information to help you take care of this crucial vehicle component. That is, from troubleshooting for issues to carrying out repairs and replacements.

Brake Calipers determine the reliability of your braking system. If they’re in bad condition, it can mean driving that’s not safe enough. For that reason, its advisable that you always keep checking the calipers to ensure they’re working properly.

Always be alert for the symptoms of a bad brake caliper. Inspect the assembly from time to time, especially during the times when you carry out routine maintenance. If you notice a problem such as a sticking caliper, move swiftly to correct it.

You could choose to replace the faulty part or parts in what’s known as caliper rebuilding. Better still, you can choose to bear the cost and install a new caliper. In summary, always ensure that the brake calipers on your car or truck are working correctly.

 

Put it all together:

 

Chapter 1 What Is A Brake Caliper

 

Chapter 2 Brake Caliper Type

 

Chapter 3 When to Replace Brake Caliper

 

Chapter 4 Bad Brake Caliper Symptoms

  1. Brake Pull
  2. Brakes That Are Less Powerful
  3. Uneven Wear Of The Brake Pads
  4. Squealing Noise
  5. Clunking Noise
  6. Leaking Braking Fluid
  7. Brakes That Feel Like They Are Engaged All The Time
  8. Dashboard Brake Light

 

Chapter 5 Caliper Diagnosis and Troubleshooting

 

Chapter 6 Brake Caliper Replacement

 

Chapter7 Brake Caliper Rebuild

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