Fork Oil Turned Black

Discussion in 'Wheels' started by BigEd, Jun 8, 2008.

  1. BigEd

    BigEd Member

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    OK...I just finished doing a Stage 1 upgrade on my 04 RK Custom. While I had it up I thought I would do a fork oil change. I have been experiencing an occasional unstable feeling in the front end. Only thing I could find was the front forks seemed awfully easy to compress and the right lower fork had a scratch on the outside rear just below the slider. May not be related. Anyway, I changed the oil to the SE heavy duty. The left oil was the color of red wine, clean and slightly viscous, but the right was thin, cloudy and black like used motor oil. It appeard to have the correct amount and I haven't noticed any leaking at all. Bike has 3000 miles on it 500 of which I have put on since I bought it. Any thoughts? Internal problem? Thanks.

    BigEd
     
  2. glider

    glider Veteran Member

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    Ed

    Possible it was serviced because of a leak or something else on one side and the cause for the clean oil in one side. Some dealers would leave a lot to be desired and only service one side if doing a repair.
    Usually the oil does come out black with shiny particles like a metallic paint would look. The 15 wt SE oil you used will firm up the front end quite a bit for you, the stock oil is a 5 wt.that was in there from the factory.

    I would just ride it and if you are suspicious of a problem, service it again after putting some miles on it and measure what comes out on both sides and compare the oil in both sides.
    The unstable feeling could have been unequal amounts of oil the the two sides before you drained it, I've seen that too.

    I have seen people use a wide variety of oils including transmission fluid in front ends.

    Here's some info oil the fork oil weights.

    Fork Oil Weights - Harley Davidson Community
     
  3. BigEd

    BigEd Member

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    Thanks Glider! That really puts my mind at ease. It will be interesting to see if there is a change. One side looked like black water and the other like hydraulic fluid. Wish me luck....going out to start it up for 1st time since finishing the Stage One last night.
     
  4. glider

    glider Veteran Member

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    Good luck and let us know how it goes.:s