Steering & suspension

Oily residue leaking from strut

An oily film on the strut body means the internal seal has failed and it's lost hydraulic fluid, which means it's no longer damping properly and should be replaced.

Difficulty
Moderate
Time
1–2 hours per side
Pro cost
$300–$700 for a pair

Symptoms

  • Visible oily wetness on the strut body, usually near the top
  • Reduced ride quality or excessive bouncing on that corner
  • Sometimes visible on both struts if they're the same age

Likely causes

  • CommonWorn strut sealSeals wear out with age and mileage, letting the internal fluid seep out.
  • Less commonImpact damage to the strut bodyA hard hit can damage the strut housing and cause a leak.

What to do

  1. Wipe the strut body clean and check again after driving to confirm it's actively leaking versus old residue.
  2. Do a bounce test on that corner; a leaking strut usually bounces excessively since it's lost its damping ability.
  3. Check the other struts too, since they're often the same age and may be close to failing as well.
  4. Replace the leaking strut, and consider replacing the matching one on the other side for even handling.
  5. Have an alignment done after strut replacement, since it can slightly affect suspension geometry.

Tools and parts

Replacement strut assemblySearch: “strut assembly for [your car model]”

When to call a pro

Struts are generally replaced by a shop, especially since coil spring compression is required and can be dangerous without the right tools.

Safety

Generally low risk

Generally low risk for a careful person. Stop if anything looks different from what this guide describes.

Related guides

Operator provides AI-generated troubleshooting information. It can be wrong. For safety-critical, electrical, gas, structural, medical, automotive safety, or other high-risk problems, consult a qualified professional.