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Existentialism-- Just a bloody good excuse to go riding...

Sunday, May 2, 2010

Maintenance...Fork Dust Seal and Foam Rings

Maintaining of forks, there's more that can be done at home with a bit of xtra effort tol keep the fork working longer before the next full servicing. Fox has outlined this on their website and its basically the same for most brand of forks to maintain the dust seals and foam rings area.

So again its nothing new and definitely more than a few have given their own version of how its being done.

Problem is that most instructions I find on the web are too scant. Especially for first timers venturing to DIY on their own it can be daunting when prying off the dust seals for fear of breaking it. Or simply find it too difficult to find an east point to start lifting those seals. When that's done, they are stuck with an o-ring that is too deep in to dig out etc...

This is supposed to make it easier for anyone who has been stumped. Fork worked on is an 09 TALAS36

First the tools needed...

Pretty self explanatory. 2 flatblade screwdrivers, one big and one small. If Fox Float Fluid (OEM Torco Assembly Fluid) is not available, just use another assembly fluid available at automotive/hardware shops. Failing which, use stanchion lubes (but those are expensive), Parktool Polylube is ok too for packing the o-rings after the cleaning but you will probably need something else when cleaning the ring itself (see below). I'm not sure if rubbing alcohol will screw up the foam rings if its used, so I'm not giving any 100% recommendation here.

Where to start prying....
The easiest is by starting next to the inaccessible portion behind the arch. The initial rise of the arch gives better leverage to push up against the seal with a small, thin flatblade.

Work both ends until the 2 sides are raised ~3-5mm and wiggle all round the rest of the seal.
I didn't tape the small screwdriver as that made it too thick to get underneath the seal initially. To avoid accidental slippage and scratching the stanchion, place a finger over it as the screwdriver is worked with an upward motion with the other hand.
Once the seal has been raised up by a few mm overall, a small flatblade will have little leverage. Time to switch to a bigger flatblade screwdriver to get the rest of the dust seal out.

One thing to note, because of all the dried up crud that collects around the lips of the dust seals, it is best after lifting the first few mm to clean around the entire surface so that none of it accidentally falls inside when the entire seal is lifted up. The portion just behind the arch would be hardest to reach. Bendy pipe cleaners would be great for the job.
Clean off the dust seals, both on the inside and outside with a Q-tip or pipe cleaner
Stuck foam ring? That's where a needle come in handy. Just pick gently and it should lift up easily.
Once out, it can be seen the inner surface is brown with dirt and grime from riding. The rings themselves are quite dry.

Beneath where the ring sits is dry and relatively clean. That confirms one of my deduction. In the past I used to lube the stanchions like most people but have stopped as I thought it was actually counterproductive.

Lubing should come from the o-rings and not when it is exposed after the seals.

Why? Ever notice apart from the dirty ring at the highest point of travel used, the seals of lubed stanchions have a substantial amount of dirt and grime after a ride. The finer particles imo can get through to the inside of the seals to the o-rings.

If the o-rings are dry then this would aggravate matters and wear things down faster. Both from not having lubrication inside that gets pushed up as the stanchion returns to position after compressing. Secondly the abrasive action of the fine particles that gets through gets trapped on the o-ring inner surface which are in direct contact with the stanchion and thus effectively "sanding" your stanchions as they go past a dry o-ring..

Lube outside dust seals-- more chance of dirt moving down.
Lube o-ring -- lube moves up and push dirt and grime back up against reaching the inside.

Cleaning the O-rings.
Add some Fox Float Fluid or whatever assembly fluid you are using. Squeeze the rings until what comes out is the same color as what was put onto it. Took a few rounds to get the rid of the grime as color changes from brown back to blue..

Gently pull on the ring and check the inner surface, it should be relatively clean by now.

 Next, saturate the o-rings with more Fox Float Fluid/ assembly fluid of choice. Push rings down and put everything back in reverse order.

 When the dust seals are in, double check that they are sitting in fully and the outer lips are flushed with the fork surface.

Compress fork a few times to double ensure that the seals will not pop off unexpectedly.

If this is done for the first time, prying of the seal is a little more difficult. Subsequently it should be much easier.


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