The Great Steel Seal Question Revisited

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by 6079smithw, May 27, 2026 at 1:44 PM.

  1. 6079smithw

    6079smithw Junior Member

    Joined:
    Jan 12, 2024
    15
    5
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    Location:
    N. Nevada
    Vehicle:
    2009 Prius
    Model:
    Base
    Hello all, looking for advice. I have a 2009 just 18 miles short of 330,000 miles. In the past month it's
    developed a minor head gasket leak; I say minor as although there are tiny bubbles in the coolant that
    pressurize it to the point it pushes the coolant out of the expansion tank there is no sign of contamination
    of either the oil or coolant (nothing on the dipstick/oil filler cap, no white smoke from the exhaust etc.)
    Ive replaced the water pump, thermostat and radiator within the last 1500 miles.


    I know replacing the head gasket is the proper fix, however, given the age and the mileage on the engine, in addition to cost, it’s not the most practical solution. I don’t want to get rid of the car because it is in excellent condition otherwise, so I have decided to throw a Hail Mary and look at some chemical solutions before I wave
    the white flag.


    From what I’ve researched it seems that Steel Seal, although expensive, seems to do the best job. I’m asking for your opinions, experience, pros, cons, caveats. i.e. input Has anybody done this? How did it work for you? Do you have any other suggestions? Any experiences, positive and negative will be appreciated.

    Thanks In Advance, Frank in Reno NV
     
  2. PriusCamper

    PriusCamper Senior Member

    Joined:
    Mar 3, 2012
    13,265
    5,358
    0
    Location:
    Pacific Northwest, USA
    Vehicle:
    2007 Prius
    Model:
    Two
    Can you explain how a headgasket failure pumps air into the coolant system? Not exhaust, not oil, but air? Not clear on how this would work?