Front Fork Seals rebuild, need a list of parts

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DoubleDuc
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Front Fork Seals rebuild, need a list of parts

Post by DoubleDuc »

Hi Group. I'm going to replace both front fork seals, I bought the 'kit' from Ebay, but I believe it only has the two rubber rings (seals), I believe I need upper & lower metal rings, maybe some bushings, but I'm not sure as to what can or cannot be reused. I have both manuals so no need there.
Here's the link to what I bought, I believe I read in another post on here that some seals didn't require the metal ring.
http://www.ebay.com/itm/280766416877?it ... m=&vxp=mtr

Could someone who has some experience w/ this provide a list of what I will need, you could just provide the part # from the manual that shows the entire front fork diagram, which I'll try to attach. It can also be found here:
http://forums.ducatipaso.org/viewtopic. ... rk+diagram

TIA
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ducinthebay
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Re: Front Fork Seals rebuild, need a list of parts

Post by ducinthebay »

TIA,
Generally, all you need is a new set of fork seals and some fresh oil. Only once you take the front wheel off the bike, and take off the fender can you tell if the bushings need replacing or not. Flex the forks for and aft to see if there is free play. Take off the fork caps and slide the forks up and down to see if the travel is smooth. If you forks are not pitted, and it has cared for, your bushings may be fine.

Cheers, Phil
Duc in the Bay
1990 750 Sport x2-Rosso Blanko (900ss copy) & Nuovo Nudo (Scrambler project)
1991 907 -mostly stock
2002 ST4s - Lots of mods.
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paso750
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Re: Front Fork Seals rebuild, need a list of parts

Post by paso750 »

those rubber rings are the fork (oil) seals. Not sure what you mean by lower and upper metal ring.
All parts numbers are in the parts catalogue:
https://app.box.com/s/lctqs86c8pvnxjp965v9
and also listed in the second link you posted (incl. numbers of alternative parts).

It`s as Phil said. You need fork seals and oil. Bushings only if there`s too much free play and new dust seals if yours are dry and cracked. (Those you can only get from a Duc parts dealer)
I believe I read in another post on here that some seals didn't require the metal ring.
That`s not correct. It`s that many of the oil seals being sold don`t have the correct dimensions and are too high in which case the snap ring can`t be fitted so some guys just didn`t. The snap ring prevents the oil seal to pop out. You might be lucky that nothing happens. I`d rather get the correct oil seals...
The ones you bought unfortunately don`t mention any dimensions.

G.
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DoubleDuc
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Re: Front Fork Seals rebuild, need a list of parts

Post by DoubleDuc »

paso750 wrote:You need fork seals and oil. Bushings only if there`s too much free play and new dust seals if yours are dry and cracked.
Thanks for all your input:

Just to clarify: I don't need the snap ring, I can reuse the old one? I was watching YouTube videos of replacing seals and it seems they destroyed the snap ring every time, of course these were different types of bikes as I couldn't find a 907.

TIA (thnx in advance)
Shawn
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Re: Front Fork Seals rebuild, need a list of parts

Post by paso750 »

yes, reuse the old ones.

Lever the snap ring out of its groove carefully with a thin screwdriver. It is an open ring with a bevel edge on its ends if I remember well. It doesn`t look like the one in the videos below.
Watch these two videos they have some good tips
https://www.youtube.com/watch?v=vrmYJgcGX30
https://www.youtube.com/watch?v=0TCYIEcDcts
As suggested on the second video loosen (don`t remove) the top cap when the fork is still on the bike and unscrew it carefully while putting some pressure on it later so it will not land in your face.
If you yank out the stanchion tube and the oil seal does not come out with it don`t try to lever it out with a screwdriver. Carefully drive a sharp screw into it warm up the outer side of the fork where the seal sits and use pliers to pull it out by the screw.

G.
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du907
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Re: Front Fork Seals rebuild, need a list of parts

Post by du907 »

I would like to throw a wrench into this wheel. :)

I have 60,000 miles on my 907. I have replaced the forks seals at least 6 times. Seems that after a few hard rides in the mountains or track days, the seals would leak. I think I still have a pair of the 907 style fork seals in a drawer.
I switched to using 900ss fork seals and have had them in my forks for 5 years now without leakage. Even after a wreck a couple of years ago, I had bent the forks and after having them straighten, I'm still using those 900ss fork seals and no leakage.

Now some small modification was required. The 900ss seals where a little taller from shoulder to bottom, so I ground off some of the rubber coating on the bottom. Also, the standard seals have a washer on top, then the C clip that holds them in place. As stated above, the C clip is required to retain the seal in place as the the tube goes up and down. So I just omitted the washer (it is very thin) and used the C clip as normal and required.

I can't remember what year I used, but they are close to the 1993 model year but newer. They have the same inside and outside diameters. You can just look at the seals and tell they are more "robust".

du907
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paso750
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Re: Front Fork Seals rebuild, need a list of parts

Post by paso750 »

I switched to using 900ss fork seals
:huh:
The Paso fork seal is 41,7x55x7,5/10mm the one for the SS Showa USD fork is 41x54x11mm.
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DoubleDuc
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Re: Front Fork Seals rebuild, need a list of parts

Post by DoubleDuc »

finally got around to trying to replace these seals; I've got stuff everywhere. I didn't realize the internal parts of the right fork were going to be different from the left. I suppose I should have - looking at the diagram now I think I can tell. Just made sense that they would be the same? The seals didn't come out when I yanked the stanchion tube out, so I suppose I'll hunt for a sharp screw to drive into the old seal and break out the butane torch as paso750 suggests. I found out there's a metal ring inside the rubber seal, so I'll look for a sharp-self tapping metal screw.
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Re: Front Fork Seals rebuild, need a list of parts

Post by Mc tool »

41.7mm is an odd size and I think some of the after market suppliers send a 42mm seal which is possibly why your seals haven't lasted . The 2 fork internals are different as one side does the compression dampning and the other does the rebound ..... so don't get the bits mixed up. G is right ( as usual :) )trying to lever the seal out can result in breaking the top of the outer tube where the lever bears against it :(
I wish I was young again............Id be heaps smarter than last time
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DoubleDuc
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Re: Front Fork Seals rebuild, need a list of parts

Post by DoubleDuc »

ok - got the old dust seal out w/ the screw trick, (came out fairly easy). I set the new one in the lower, receiving - larger black tube thing (sorry about my terminology) and found that it loosely fits, it could fall right out. But it's tight around the chrome pipe. Do you think it will still hold the oil? Will try to attached picture. Picture won't attach?
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Re: Front Fork Seals rebuild, need a list of parts

Post by paso750 »

the chrome tube is the stanchion tube, the lower the fork slider.
You should be able to pull out the dust seal by hand. The screw is for the oil seal.
Which one of the two are you referring to?
The oil seal is a tight fit. You`ll have to get it on the stanchion tube. Put the stanchion in the slider and drive the seal in (as you can see in the videos). The dust seal does not sit very tight.

The dimensions are printed on top of the oil seal. What are they?
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Re: Front Fork Seals rebuild, need a list of parts

Post by ducinthebay »

I bought a set of the Pyramid dust seals, as all the old ones are cracked. The Pyramid dust seals fit the fork leg (stanchion) just fine, but are loose in the fork leg (slider) If I bounce the fork up and down, the dust seals come out of the fork slider and just stick to the fork leg.

So far, all of the Pyramid stuff has shown its not fit for use.

Again, buy top shelf stuff, and do the job once, or at least buy them once. Since I bought them a year or so ago, I can't remember who I bought them from, so I can't return them. So now I'm buying new ones.

Seems the Ariete stuff seems to be decent quality as best I can tell. Any input otherwise?
http://www.ariete.com/en/catalog/ari-pa ... orcella-1/

Cheers, Phil
Duc in the Bay
1990 750 Sport x2-Rosso Blanko (900ss copy) & Nuovo Nudo (Scrambler project)
1991 907 -mostly stock
2002 ST4s - Lots of mods.
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DoubleDuc
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Re: Front Fork Seals rebuild, need a list of parts

Post by DoubleDuc »

The dimensions are printed on top of the oil seal. What are they?

Thanx for the quick replies: I just realized when I set the oil seal in the Lower Fork Slider it's depth is too large to allow the metal retaining clip to fit into its groove. So I was sold an oil seal for a 907 that doesn't fit a 907. It's outer diameter is too small and depth too large :(. I'll review the previous posts here or go to the local Duc shop (which I hate to do) and buy a couple there.
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Re: Front Fork Seals rebuild, need a list of parts

Post by paso750 »

check what is printed on them.
The correct size is 41,7 x 55 x 7,5/10mm (Ariete ARI.083). Many shops sell the 41,7 x 55 x 10/10,5mm as a correct match but the 2,5mm additional height is what causes the issue with the retaining clip.
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Re: Front Fork Seals rebuild, need a list of parts

Post by paso750 »

thinking about the comment above about the 900SS seals, I wonder if that is what you got. 41x54x11mm would sit tight on the stanchion tube but loose the slider tube and they`re too high as well.
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