What parameters define a bad strut?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by MrPete, Jun 24, 2025 at 7:25 PM.

  1. MrPete

    MrPete Active Member

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    Doing my first DIY shocks/strut replace...

    ...and I am beginning to wonder if the typical "quick and easy" diagnostics are sufficient.

    Lots of people say either or both of:

    A) Does the car bounce if jostled or goes over a big bump?

    B) Is there evidence of a fluid leak from the strut?

    The ride on our 2011 has just felt off a bit. No obvious issues.

    I just pulled a rear strut and compared to a brand new one.

    The primary difference is in how long it takes to re-expand of I manually push in the piston while out of the car. Obviously not an in-car test

    New: around 10 sec
    Old: around two minutes

    Other than that, the old one displays no failure symptoms.

    Thoughts?
     
    #1 MrPete, Jun 24, 2025 at 7:25 PM
  2. Tombukt2

    Tombukt2 Senior Member

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    Look at sites like Monroe and kyb depending on tube designs you can read all about what happens to has as seals wear internally the stuff don't move thru the valve like it's sposed to gas and oil loss affect rebound all that good stuff.
     
    #2 Tombukt2, Jun 24, 2025 at 7:40 PM
  3. MrPete

    MrPete Active Member

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    .
     
    #3 MrPete, Jun 24, 2025 at 8:05 PM
    Last edited: Jun 24, 2025 at 11:04 PM
  4. tweedle99

    tweedle99 Member

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    My OE never developed any leak but had a lot of mileage and "felt off" like how you felt. The OE rear shocks never rebound when pushed in which meant that the springs were doing all the rebound.

    My replacement was Gabriel which later developed visible leak on one side and mfr warranty me the pair.

    I would recommend installing the rear sway bar. Makes the car less "squirrelly" on the freeway, especially on curves.
     
    #4 tweedle99, Jun 25, 2025 at 2:46 AM
  5. Tombukt2

    Tombukt2 Senior Member

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    A larger sway ? Ones they're already is it not on the 3?
     
    #5 Tombukt2, Jun 25, 2025 at 8:10 AM
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