Applications:
Universal joints are commonly used in vehicles to connect the transmission to the drive shaft and in steering systems to transmit power between the steering column and the wheels. They are also found in industrial machinery, agricultural equipment, and even in some household appliances.

Construction and Function:
Brake rotors are typically made of cast iron or sometimes carbon ceramic materials. They are mounted directly onto the wheel hub and rotate along with the wheel. When the brake pedal is pressed, brake pads are clamped onto the rotor, creating friction that slows down the rotation of the rotor and wheel, thus bringing the vehicle to a stop.

Coolant is a liquid substance that is commonly a mixture of water and ethylene glycol or propylene glycol. Its primary function is to regulate the temperature of the engine by absorbing heat generated during the combustion process and transferring it to the radiator, where it is cooled. By doing so, coolant prevents the engine from overheating, which can lead to serious damage such as warping of engine components or a complete engine failure.

In conclusion, the crankshaft is a critical component of an internal combustion engine that converts linear motion into rotational motion to propel a vehicle. Its design and function are essential to the overall performance and efficiency of the engine. Understanding the operation and maintenance of the crankshaft can help ensure the smooth operation of the engine and prolong its lifespan.

Maintenance and Repair:
Regular maintenance and timely repairs are essential for ensuring the proper functioning of brake calipers. It is recommended to have your brakes inspected by a qualified mechanic during routine service intervals to catch any issues early on. If you suspect a problem with your brake calipers, it is crucial to have them inspected and repaired promptly to avoid potential safety hazards on the road.

When replacing brake rotors, it is recommended to replace them in pairs to ensure balanced braking performance. Additionally, it is crucial to follow the manufacturer's recommendations regarding rotor specifications and installation procedures to maintain the integrity and safety of the braking system.

Design and Functionality:
A universal joint typically consists of two yokes connected by a cross-shaped or spherical mechanism, known as the joint itself. Each yoke attaches to one of the two shafts that need to be connected, and the joint allows for movement in multiple directions. This design enables the shafts to rotate at different angles and speeds without losing rotational power or torque.

Signs of Brake Caliper Issues:
It is essential to recognize the signs of potential brake caliper problems to ensure the safety and performance of your vehicle. Here are some common indicators that your brake calipers may be failing:
- Uneven brake pad wear: If you notice that one brake pad is more worn down than the others, it could be a sign that the caliper is sticking.
- Squealing or grinding noise: Unusual noises when applying the brakes could indicate worn-out brake pads or a malfunctioning caliper.
- Pulling to one side: If your Vehicle Emissions Control pulls to one side when braking, it may be due to a stuck or seized caliper.
- Brake fluid leaks: Visible brake fluid leaks around the caliper could suggest a seal or piston failure.

Additionally, coolant helps prevent corrosion and rust formation within the engine by lubricating and protecting metal surfaces. It also contains additives that prevent the growth of algae, fungi, and bacteria, which can clog the cooling system.

Function:
The primary function of a crankshaft is to convert the reciprocating motion of the pistons into rotational motion. This process is crucial for transferring power from the burning fuel mixture in the cylinders to the wheels of the vehicle. As the pistons move up and down in the cylinders, the connecting rods attached to them push and pull on the crankshaft, causing it to rotate. This rotational motion is then transferred to the transmission and ultimately to the wheels, propelling the vehicle forward.

Performance and Maintenance:
Proper maintenance of brake rotors is essential for optimal braking performance and safety. Over time, brake rotors can wear out due to heat, friction, and general wear and tear. Common signs of worn-out brake rotors include vibration or pulsation when braking, squealing noises, and decreased braking efficiency. It is crucial to have the brake system inspected regularly and replace or resurface the rotors when necessary.

Proper maintenance of coolant is crucial for the overall health and longevity of a vehicle's engine. Using the correct type of coolant and maintaining the proper coolant levels is essential to prevent overheating and costly repairs. Improper coolant levels or neglected coolant maintenance can lead to engine overheating, inefficient cooling system performance, and potential engine damage.