Hydraulic lash adjusters

Types of hydraulic lash adjusters

HLA are small yet essential components fitted in the internal combustion engine's valve train system. They help maintain optimal clearance between the engine's moving parts, ensuring smooth and efficient operation. In a nutshell, HLA keep the engine running quietly and help it last longer. There are two main types of hydraulic lash adjusters: roller and ball-tip.

• Roller HLA

  Roller HLA are designed with a roller tip that resembles a small wheel. The roller tip allows the HLA to slide over the camshaft gently and precisely, reducing wear and tear on the engine parts. As a result, the engine runs smoothly, and the HLA last longer. Roller hydraulic lash adjusters are mainly used in high-performance vehicles and V6 and V8 engines.

• Ball-tip hydraulic lash adjusters

  Ball-tip hydraulic lash adjusters have a rounded ball tip. This design allows the HLA to make direct contact with the camshaft lobes. The ball tip designs make the ball HLA more affordable and less complex compared to their roller counterparts. However, the wear and tear on the engine parts is slightly higher than roller hydraulic lash adjusters. For this reason, ball-tip HLA are widely used in small cars and affordable vehicles.

HLA also come in different sizes and designs to suit various vehicle models and engine types. For instance, some hydraulic lash adjusters may have a one-piece or split-body construction. One-piece HLA are more common and widely used in most vehicle models. On the other hand, split-body hydraulic lash adjusters are complex and suitable for high-performance vehicles.

Specifications and maintenance of hydraulic lash adjusters

Specifications of hydraulic lash adjusters vary from one model to the next. Here are some of the most common ones:

• Size

  The size of the lash adjuster is determined by the diameter of the body. It ranges from 7.9 mm to 16 mm. The size must be compatible with the engine valve train system.

• Travel

  Travel refers to the maximum distance the plunger can move. It is measured in mm. The travel distance accommodates thermal expansion and tolerates manufacturing variations.

• Load capacity

  Load capacity refers to the force that the lash adjuster can generate to open and close the engine valves. It is measured in Newtons. The load capacity must be compatible with the engine's spring force and cam profiles.

• Material

  Hydraulic lash adjusters are made from durable, corrosion-resistant materials. Common material options include steel, aluminum, and plastic. Steel is often used for the hydraulic lash adjuster body and other internal components. Aluminum is lightweight, making it suitable for the plunger and other moving parts. Plastic is used for the seal and other external components.

• Seal performance

  The seal performance of the hydraulic lash adjuster is crucial in preventing oil leaks and ensuring effective lash adjustment. The adjuster seal must be compatible with the engine oil and other system fluids.

• Pressure range

  The pressure range specifies the operating pressure and the tolerable variations. The lash adjuster pressure must be consistent with the engine oil pump pressure.

• Flow rate

  Flow rate refers to the volume of oil transferred through the lash adjuster per unit time. It ensures even distribution of oil to all adjusters, maintaining consistent valve operation. The flow rate must match the engine's oil pump flow capacity.

Like any other mechanical component, hydraulic lash adjusters require regular maintenance to operate efficiently. Here are some tips on how to maintain hydraulic lash adjusters:

• 1. Use quality motor oil recommended by the manufacturer to ensure smooth operation.
• 2. Keep the valve train clean by following the manufacturer's cleaning recommendations.
• 3. Avoid overloading the engine by adhering to weight limits for vehicles and equipment.
• 4. Follow the manufacturer's maintenance schedule and recommended service intervals.

How to choose hydraulic lash adjusters

Before buying HLA, it is important to understand the factors that affect their performance. Below is a guide to help choose the right hydraulic lash adjusters.

• Engine type

  Consider the type of engine when buying HLA. Some engines require more precise valve timing to optimize performance. Such engines need HLAs that can handle high-pressure situations. For instance, choosing a thicker HLA can be a good idea.

• Driving conditions

  Driving conditions such as road and weather conditions affect the choice of hydraulic adjusters. If the roads are mostly paved and the weather is moderate, a standard HLA is sufficient. However, when driving on unpaved roads with extreme weather conditions, one should opt for HLAs with better wear resistance and durability.

• Maintenance

  Maintenance is an important factor to consider when choosing hydraulic lash adjusters. Choosing the right engine oil is crucial, as oil with the wrong viscosity can damage the HLA. Additionally, regular oil changes are necessary to ensure the HLA lasts longer.

• Brand and quality

  It is important to consider the brand and quality of the hydraulic lash adjuster. Well-known brands are usually of high quality and increase the HLA's reliability. One can also ask for recommendations from a trusted mechanic.

How to DIY and replace hydraulic lash adjusters

Before attempting to replace an HLA, it’s essential to read the car’s repair manual. The manual provides the necessary steps to take when replacing the HLA. Here are some general steps to follow when replacing the hydraulic lash adjusters.

Car owners will need the following tools to replace the hydraulic lash adjusters successfully.

• Socket set
• Wrench set
• Torque wrench
• New hydraulic lash adjusters
• Engine oil
• Oil filter
• Oiling wrench

It’s advisable to wear safety glasses and gloves. After preparing the work area, the next step is to disconnect the battery.

• 1. Remove the engine cover: The engine cover is removed using a socket or wrench. After this, the air intake hose is disconnected from the engine. This step allows access to the valve cover.
• 2. Remove the valve cover: The valve cover is removed after loosening the bolts. Doing this provides access to the HLAs.
• 3. Remove the rocker arm assembly: The rocker arm assembly is removed after disconnecting the push rods. It’s important to note that the assembly may be connected using bolts or nuts.
• 4. Remove the old hydraulic lash adjusters: The old hydraulic lash adjusters are removed carefully. This process is done using a suitable wrench or socket.
• 5. Install new hydraulic lash adjusters: The new HLAs are lubricated using fresh engine oil. They are then positioned into their respective locations. It’s crucial to ensure that the HLA’s seating surface is clean and free from debris before installing the new adjusters.
• 6. Reassemble the engine: The process of reassembling the engine is done in reverse order. First, the rocker arm assembly is reinstalled. After this, the valve cover is reinstalled and the engine is started. The battery is reconnected after the valve cover, and the HLA’s have been successfully replaced.
• 7. Check for any leaks or unusual noises: After starting the engine, the battery is reconnected. The HLA's and the valve cover are checked for any leaks. The hydraulic lash adjusters are also checked for unusual noises.

Q and A

Q1: What are the benefits of using new hydraulic lash adjusters?

A1: New hydraulic lash adjusters provide several benefits. They help maintain proper valve clearance, improving engine performance. This can result in better fuel efficiency and reduced emissions. Furthermore, they contribute to quieter engine operation by minimizing noise and tapping. Overall, the hydraulic lash adjusters enhance the engine's performance, efficiency, and longevity.

Q2: Can one clean and reuse hydraulic lash adjusters?

A2: Reusing hydraulic lash adjusters is not generally recommended. While it may be possible to clean them, ensuring they function like new ones is challenging. Over time, hydraulic lash adjusters can wear out and lose their ability to maintain proper valve clearance. This can lead to engine performance issues. Therefore, replacing the hydraulic lash adjusters with new ones is advisable to ensure optimal engine performance and reliability.

Q3: What is the expected lifespan of hydraulic lash adjusters?

A3: The lifespan of hydraulic lash adjusters can vary based on factors such as maintenance, engine condition, and driving habits. However, replacing them every 50,000 to 100,000 miles or as recommended is generally advisable. Checking the hydraulic lash adjusters regularly is essential to ensure they function correctly and maintain proper valve clearance. This can help prevent engine performance issues and extend the engine's lifespan.

Q4: Are there any specific signs of a failing hydraulic lash adjuster?

A4: Yes, there are several signs that can indicate a failing hydraulic lash adjuster. These include a tapping or ticking noise from the engine, especially during operation. Other signs include a rough or uneven engine performance, a decrease in engine power, and an increase in engine vibration. If any of these symptoms are noticed, it is advisable to check the hydraulic lash adjusters and replace them if necessary to ensure optimal engine performance and reliability.

Q5: Can hydraulic lash adjusters be repaired?

A5: Repairing hydraulic lash adjusters is generally not recommended. These components are precision-engineered to maintain proper valve clearance in the engine. If they become faulty or worn out, their performance cannot be guaranteed, even with repairs. Moreover, repairing hydraulic lash adjusters can be costly and time-consuming. Therefore, replacing them with new ones is advisable to ensure optimal engine performance and reliability.