Contaminated fork oil?

**Pumba** · 18th January 2009, 17:17

Just drained the forks on my bucket (GSXR250 front end). Now the fork oil isint that old (6 months max) but one fork legs oil was significantly more cloudy than the other, which was of a colour and consistancy I would expect.

Any idea what would have caused this? or what it is telling me about how my forks are operating?

**riffer** · 18th January 2009, 18:32

The fork seals aren't a perfect seal and air gets in.

When air gets in, it brings in contaminants. Sometimes one seal is better than another.

Perfectly normal, I reckon.

**Pumba** · 18th January 2009, 19:08

That was my first thought as well, but my second thought was I would throw it out to the masses and see if I could learn smothing new today, just in case I was wrong.

**Blackbird** · 18th January 2009, 19:20

When I fitted some performance springs and valves to the 'bird late last year, mine contained pretty much low viscosity grey sludge. The forks hadn't been apart in 60000 km. Simon's right about seal leakage but internal friction and consequential metal wear debris also contributes to discolouration. Amazing how clean oil helps!

**Pixie** · 19th January 2009, 17:39

Most of the contaminants that collect in fork oil are due to the spring rubbing against the inside wall of the fork tube and this may differ from one leg to the next.
Some quality springs,such as Traxxion, come with a guide that sits in the centre of the spring to prevent it touching the tube wall.

**Robert Taylor** · 20th January 2009, 12:10

Originally Posted by Pixie

Most of the contaminants that collect in fork oil are due to the spring rubbing against the inside wall of the fork tube and this may differ from one leg to the next.
Some quality springs,such as Traxxion, come with a guide that sits in the centre of the spring to prevent it touching the tube wall.

Correct and some oils break down much faster than others. Also if there is a significant amount of virgin ( non anodised ) alloy in the forks it reacts with the oil and junks it real quick.

**Shaun** · 22nd January 2009, 05:49

Originally Posted by Robert Taylor

Correct and some oils break down much faster than others. Also if there is a significant amount of virgin ( non anodised ) alloy in the forks it reacts with the oil and junks it real quick.

As well as, if the forks are not completely stripped and thouroughly cleaned out, a lot of junk still stays in the fork internals as well, causing the oil to pollute quickly.

**Pumba** · 22nd January 2009, 07:23

Thanks guys, really alot of what I thought it was telling me but it is nice to have it confirmed by those with far more experience.

**elevenhundred** · 3rd February 2009, 14:39

A friend of mine took his bike into a shop to have the front forks checked out and have the oil replaced. A couple years later I bought the bike off him, I didn't like how the forks felt so I checked them out myself, one leg was fine and had clean oil at the correct level in it but the other had a thin, murky liquid in it which had a strong petrol smell to it. Me thinks they were still cleaning it when it was put back together and given to the customer.
I guess my point is you never know what you're gonna find

**motorbyclist** · 4th February 2009, 10:37

my mate bought a 250 bandit from colemans

took it back under warranty when a fork seal went

a few months later, a fork seal goes again. so we buy a pair of seals and pull the forks apart. interestingly, one fork had the spacers and springs in a different order to the other, one had a new seal while the other was obviously years old, yet both had very murky oil. one fork was also much more difficult to disassemble than the other.

what exactly colemans did with the oil is unclear, but the fact they only replaced the leaking seal and then reassembled it incorrectly is a very bad look. what exactly are they going to do with the left over seal? rip another customer off, perhaps?