M600 Fork Oil Capacity and Level?

[Samurai]

I've replaced fork seals on several Ducatis in the past but have never had this particular problem.

Going by both an official Ducati workshop manual and the Haynes version, the capacity is 380ml per leg, with an air gap of 90mm to the top of the slider.

However, having duly stripped, cleaned and completely drained the first fork, I measured out the correct quantity, poured it in and measured an air gap of about 180mm!

I've pumped the damper rod numerous times to ensure there is on air in there, rechecked the level and still the same. I was expecting to add or subtract maybe 20 or 30ml, but to actually get the 90mm gap I've had to almost double the quantity of oil in the leg.

What makes me think that something is seriously wrong with the info in the manuals is that when I then put the spring and tube back in, the oil level is right at the top of the slider!

The fork is fully collapsed and the damper rod pushed fully home when I'm measuring and the spring etc is not in.

Can anyone advise me as to what I'm doing wrong or if the measurements in the manuals are incorrect?

[Flip]

What make forks do you have fitted as there is a difference between Showa and Marzocchi specs.

[Samurai]

Good point well made!
Now that I check the mauals more carefully, the specs they are both giving are for Marzocchi but I've got Showa ones!

Any ideas as to the capacity and air gaps on those?

Any help much appreciated.

[Flip]

The only information I can find for oil capacity on the Showa forks is GD031 and GD041 is fill with 457ml giving an oil level (measured from the top of the tube without the spring and the leg compressed fully) of 79.5mm.

[Samurai]

Thanks mate, the oil capacity is much nearer to what I had to put in to achieve the 90mm air gap. Though once I put the spring and preload tube in the oil level was pretty much at the very top. Can this be right?

[Flip]

Yes but the 90mm gap was for the Marzocchi's remember.

I only have information for Showa which says 79.5mm gap with 457ml of oil or 108mm gap with 440ml of oil but I think the latter is for the SS models with the adjusters on the top of the forks.

I'm sure there must be someone here that has a 600 Monster with Showa forks that knows the correct quantity and level measurement??

[DrD]

Flips's figures are standard numbers for M900.
Presumably you are adding oil with the forks compressed and doing the pumping action on the damper to dispel the air.
Once this is done, if you extend the forks for springs and rest you should not be topping out the oil.
Haynes manual does cover that.
Ducati EU manual for M600 is at: http://www.duc.nu/?model=monster

[Mr Gazza]

My (Ducati) manual for 900ie concurs with DrD.

I para phrase...Add half the oil with the fork leg in a vertical attitude. Then give the rod and slider 10 pumps of at least 100mm stroke.
Then move the rod and slider to the end of thier travel...It doesn't say which end, but the picture shows the rod level with the top of the tube...So I'm guessing that's extended.

Air gap is 80mm for standard Showas and 108 for Sie adjustable Showas.

A quantity of 0.44 litres is given but does not differenciate between standard and Sie..So I would guess you would keep adding till the air gap is correct after having pumped the air out as described.

[Samurai]

Ok, hands up been a bit dumb in part! If course when you extend the forks after having measured the level, it won't be at the top of the forks even with the springs in . . . Doh!!

However, there's a bit more to this. Whilst cleaning up the fork legs I find the small stamped model numbers at the bottom inside edge. They say that the forks are GD051-50's which, from what I can find in the interweb were fitted to the last carbed models (mine is a 2000 model year). They are non-adjustable and none of the Monster manuals I've got, or even the original owners handbook mention them!

Soooo, it's the oil level for these that I need if anyone has it. Oh, and don't say measure the one you've not worked on yet as we had a bit of a spillage last night whilst trying that :-(

[slob]

I can probably comfirm for you tonight, when I get home.

[Samurai]

Cheer Slob, that would be much appreciated.

[slob]

MY02 620/750ie, which I believe uses the same non-adjustable Showa fork:

0.440 litre Shell Advance 7.5 fork oil or Dontax TA per leg.
The factory manual doesn't give an air gap.
... and somewhat confusingly says 0.410 litre elsewhere (so I'm assuming that's for a oil change rather than a rebuild)

Pour in approx. half the oil, to cover the damper holes and pump the damper ten or more times, at least 150mm per stroke, then pour in the remaining quantity.

[Samurai]

Slob you're a Gent!

The volume you give would pretty much coincide with what I managed to catch when I drained the second leg. I caught 350ml and would hazard a guess that about 50ml or more ended up on the garage floor.

Too tip, if you ever want to catch ALL the oil, ignore the manuals and DO NOT loosen the damper for bolt at the bottom of he fork in situe!

I only cracked it a quater of a turn, but after I completely removed the top cap the release of he vacuum, together with the fact that in unscrewing the top cap further unscrewed the damper bolt,oil starts to **** out the bottom!

Hence the loss of about 50mls . . .and by he way you can usually remove the damper bolt afterwards anyway, I just though that I'd make it a little bit easier on myself. . . Ho hum!

Thanks to all who have helped in this thread. The moral of the story is yet again is you can't rely on Ducati manufacturing bikes with any consistency in components used :-)

[Samurai]

Hi Guys,

Just to let you know that I've just stripped and filled the second fork with the 440ml that Slob found in the manual for the 620 and 750ie. The air gap it gives if anyone needs to know in future is 135mm.

Thanks to all who chipped in with help:heart::biggrin: