How do I know if my hood struts are bad?

Hood struts that are failing typically cause the hood to drift or fall, fail to stay up, or show signs of leakage or damage. If you notice one or more of these issues, the hood struts are likely worn and should be replaced.

Hood gas struts are designed to hold the hood open and guide its movement. Over time, their seals wear out, the gas pressure diminishes, and the struts can become stiff, sluggish, or leak oil. Problems usually develop gradually, but a failing hood strut can pose a safety risk if the hood suddenly drops while you’re working under it. This guide explains how to recognize the symptoms, how to test them safely, and what to expect if you replace them.

Understanding hood struts and why they fail

The hood struts (often called gas springs or lift supports) are compact hydraulic cylinders mounted on each side of the engine bay. They use pressurized gas sealed inside a cylinder to provide upward force, making it easier to lift the hood and keep it open. Common reasons for failure include seal wear, internal gas leakage, rust or corrosion, and mounting point wear. If one strut fails, the other may still work, but the hood will tilt or feel unbalanced.

Common warning signs

These are the most frequently reported indicators that a hood strut may be failing. If you notice one or more of these, it’s worth inspecting the struts or having them checked by a mechanic.

• The hood no longer stays up on its own and slowly sags or falls open.


• The hood slams shut or feels heavy to lift, requiring extra effort to hold it up.


• One side looks visibly weaker than the other or the hood tilts to one side when opened.


• Visibly damaged struts, bent rods, or corrosion on the mounting points.


• Oil or hydraulic fluid leakage around the ends of the struts or on the piston shaft.


• Unusual noises like creaking, popping, or hissing when opening or closing the hood.


• Slower or inconsistent operation—retains less resistance and moves more freely than normal.

A single failed strut can affect hood alignment and safety, so undiagnosed signs are worth a professional check, especially if you drive a car with a heavy hood or newer electronics bays near the hinges.

How to test hood struts safely

Use these steps to confirm suspected weakness at home. Always prioritize safety and consider enlisting a helper when handling a heavy hood.

1. Open the hood to its full height and, with both hands, gently push the hood upward and then let go. It should stay in place or require a little resistance to move. If it slides downward on its own, the struts are weak.


2. With the hood still open, try lifting the hood from a mid-range position and release it. A healthy strut will resist collapsing and hold its position; a failing one will let the hood drop more quickly than usual.


3. Inspect the visible portions of both struts for oil leakage, corrosion, or bent, damaged, or misaligned mounting points.


4. Check the mounting hardware (bolts or brackets) for looseness. Tighten only if you know the correct torque for your vehicle, as overtightening can strip threads.


5. Repeat the test on both sides to see if both struts perform similarly. If one side is markedly weaker, plan to replace both to maintain even hood support.

Testing provides a baseline assessment. If you notice a significant difference between the two sides or any leakage, consult a mechanic for a precise diagnosis and replacement guidance.

Cost and replacement options

Costs vary by vehicle and part quality, but here is a general guide to what you can expect when replacing hood struts. Replacing both sides is common for balanced performance.

• Parts: Aftermarket hood struts typically range from $20 to $70 per strut; OEM or high-end variants can run $50 to $120 each. Buying a matched pair is common to ensure even operation.


• Labor: If you use a shop, expect roughly $60 to $150 per hour for installation, with 0.5 to 2 hours of labor depending on access and vehicle model. DIY replacement usually takes 30 minutes to an hour per strut for a basic job on many cars.


• Total cost estimate: Replacing both sides can run roughly $100 to $300+ in parts and $40 to $300 in labor, depending on parts choice and whether you DIY or hire a pro.

Prices vary by region and vehicle, so check current parts catalogs and local labor rates. If you’re unsure, a quick diagnostic at a shop can confirm whether you need one strut or a full pair.

DIY tips and safety

If you decide to replace hood struts yourself, follow these practical tips to stay safe and get a reliable result.

• Work with the hood fully supported and supported by a second person or a proper prop when needed to prevent sudden closures.


• Buy a matched pair of struts designed for your exact vehicle model and hood weight.


• Handle struts gently; they are under pressure and can be dangerous if damaged or punctured.


• Follow the manufacturer’s installation orientation and torque specifications for mounting bolts.


• Dispose of old struts according to local regulations; many auto shops will recycle or dispose of them properly.

If you’re unsure about the process, or your hood has an unusual mounting arrangement, it’s wise to have a pro perform the replacement to avoid misalignment or hood damage.

When to call a professional

Consider professional service if you notice any of the following besides the basic symptoms above:

• One or both struts show signs of leakage or corrosion that you cannot repair at home.


• Hood alignment is visibly off, or the hood rubs against the fenders or seals when opening or closing.


• Struts require disassembly near electrical components or aftermarket lines that demand specialist handling.


• You’re unsure about diagnosing, removing, or installing the struts safely.

A professional can confirm whether you need one or both struts replaced and ensure proper alignment of the hood mechanism.

Summary

Hood struts are essential for safe and easy hood operation. Signs of failure include a hood that won’t stay open, slow or uneven movement, visible leaks or damage, and unusual noises. You can test them safely at home by checking how the hood behaves when you release it at open height and by inspecting for leakage and mounting wear. Replacement costs vary, but most people replace both struts to maintain balanced performance, whether DIY or through a shop. If you’re not confident performing the replacement, seek professional help to ensure proper alignment and safety.

Why do hood struts fail?

Hood struts fail primarily due to wear and tear over time, causing seals to degrade and leak the internal pressurized gas and hydraulic fluid. Other causes include physical damage like corrosion or bending from impact, and environmental factors like temperature changes, which can degrade seals and reduce gas pressure.
 
Reasons for failure

• Seal and gas leakage: The seals that contain the pressurized gas and hydraulic fluid will eventually wear out. As the seals fail, gas leaks out, causing the strut to lose its ability to hold the hood up. 
• Physical damage:
  • Corrosion: Moisture and road salt can cause rust on the piston rod. The resulting rough surface can damage the seal, leading to leaks. 
  • Impact: Forcing the hood shut, incorrect installation, or other physical impacts can bend or damage the strut, preventing it from working smoothly. 
• Age and usage: Even without obvious damage, normal wear and tear from repeated opening and closing, combined with temperature fluctuations, will cause the internal components to fatigue and the struts to lose pressure over time. 

You can watch this video to learn how to replace hood struts: 59sJack FletcherYouTube · Jan 8, 2023
Consequences of failure

• Sinking hood: A failing strut may cause the hood to slowly lower on its own, and eventually, it will not stay open at all. 
• Sudden failure: In some cases, a strut can fail suddenly, causing the hood to crash down, which can lead to injury or damage to the vehicle. 

What are the symptoms of bad struts?

Symptoms of bad struts include a bouncy or overly harsh ride, nose-diving when braking or squatting during acceleration, excessive body roll in corners, and unusual noises like clunking or squeaking. Other signs include uneven tire wear, leaking fluid on the struts, and a shaking steering wheel.
 
Handling and ride quality 

• Bouncy or bumpy ride: The vehicle continues to bounce multiple times after hitting a bump instead of settling down quickly. 
• Excessive body roll: The car sways or leans more than usual when turning corners. 
• Nose-diving: The front end dips excessively during hard braking. 
• Rear squat: The rear of the vehicle sags or squats when you accelerate. 
• Decreased steering control: You may feel less stable or have a harder time steering, especially during sharp turns or in windy conditions. 

Noises

• Clunking or knocking: A hollow sound that can happen when going over bumps or when the suspension moves suddenly.
• Squeaking or grinding: Can indicate worn-out strut mounts or bearings, especially when turning.
• Creaking or groaning: A sign of worn-out bushings within the strut assembly. 

Other indicators

• Fluid leaks: Leaking hydraulic fluid on the outside of the strut or in the wheel well is a clear sign of failure. 
• Uneven tire wear: Look for "cupping" or "scalloping" on your tires, which happens when they aren't making even contact with the road. 
• Vibration: A shaking or vibrating steering wheel, especially on smooth roads, can point to worn struts or shocks. 
• Longer stopping distances: Worn struts reduce your car's ability to stop efficiently. 

How to tell if hood struts are bad?

Here are three signs of bad hood struts so you know to swap them out promptly.

1. You were one of the first hood strut lift kit adopters (struts are getting old!)
2. You hear squeaking or other noises when you open and close the hood.
3. The hood fails to stay open, whether it slowly closes or falls quickly.

How to maintain hood struts?

To maintain hood struts, regularly wipe down the strut shafts with a damp cloth, apply a silicone or other suitable lubricant to the shafts and pivot points, and clean the ball joints with a degreaser before re-lubricating them. However, since gas struts are sealed units, maintenance primarily focuses on cleaning and lubrication; ultimately, they will need to be replaced when they can no longer hold the hood open. 
Step 1: Clean the struts

• Support the hood securely with a prop rod before you begin. 
• Wipe down the strut shafts with a damp cloth to remove any dirt or dust. 
• Use a degreaser to clean the ball joint and pivot points on both the strut and the vehicle body to remove old grease and debris. 

Step 2: Lubricate the struts 

• Apply a light oil or silicone spray to the strut shafts. Some recommend dry lubricant for hinges to prevent dirt from sticking. 
• Lubricate the ball joints with a suitable grease after they have been cleaned. 

You can watch this video to learn how to clean and lubricate hood struts: 1m4DIYersYouTube · Aug 9, 2019
Step 3: Check for and address issues

• Inspect regularly: Periodically check the struts for any signs of leaks or damage. 
• Listen for noises: If the struts make squeaking noises when the hood is opened, cleaning and lubrication may help. A dry lubricant on the hinges might be especially helpful for this. 
• Test the lift: After maintenance, carefully lower the hood and then open it to ensure the struts are working correctly. 

This video demonstrates how to replace a worn-out hood strut: 56sJack FletcherYouTube · Jan 8, 2023
Step 4: Replace the struts if necessary 

• If the struts are leaking, difficulty holding the hood open, or are otherwise damaged, they should be replaced. 
• Do not attempt to recharge the gas inside the struts yourself, as this requires special equipment and training. 
• When replacing the struts, it's best to do both at the same time.