I have just replaced the standard fork springs on my 2007 Dyna with progressive suspension springs. I decided to change the fork oil at the same time and discovered that the oil in the right hand fork was light brown in colour and slightly dirty looking. The oil in the other fork was bright red and clear. The bike has done 8000 miles. Any clues to what may have caused this ?

 

I would guess that moisture is getting in. Stop riding in the rain! Must be awful weather in Surrey.....

 

The harley fork oil is crap. I've no changed it out of 2 harleys that had original fork oil in it and it was plain nasty and stinky.

Watch the seals on the newer dyna's. I had mine replaced under warranty at 3k miles. They also found one of the fork tubes had a slight tweek to it and would have caused 1 of the seals to wear out quick

 

Yes a mate said it might be water getting in. Not in Surrey though, New Zealand. South pacific styles haha

 

Put NZ in your location, there's a good chap. We have three Redhills over here and it also helps emphasis how International HDF is.

Best of luck sorting your forks!