Fox Float 100mm - Changing Seals - How To

Although I'd been pleased with my new forks, there's always a risk when buying used that they won't be in tip top condition.  Unfortunately after a couple of rides its was clear that an excessive amount of oil was leaking from the seal on the stanchion of the right leg.  Now although this was a nuisance its not too expensive or indeed difficult to replace the seals.  Which for a fork with 32mm stanchions can be picked up for around $25 a set.

Here's my guide on how to replace the seals

Fox fork seals and 10wt fork oil

Just to illustrate the problem you can see from the below picture there's a lot of gunk and oil seepage around the seal on the right stanchion.

First step is to place the forks at an angle and to remove the nuts on the bottom of the forks using a 10mm socket which will then allow you to remove the lowers by tapping lightly an the threads with a hammer and then pulling the forks apart.

Using a 10mm socket remove the nuts holding the lowers in place

Whilst removing the lowers its a good idea to soak the new foam in oil ready for installation.

With the lowers seperated from the stanchions next step is to drain the oil into a suitable container.

The old seals can be removed by popping them out with the open end of a large wrench and then pulling out the foam inserts.  The rather black and grimy looking foam roller is in the center of the below picture next to the one which was removed form the left stanchion.  The foam insert was caked in dirt and almost rock hard, which explains fully why the seal was functioning so poorly.

With the old seals out its a good idea to give the lowers and stanchions a clean, brake cleaner is good for this however I had some carb cleaner laying around which works just as well.

After spraying the cleaner into the lowers, I find it most effective to roll up a couple of sheets of kitchen roll to clean the internals.

Despite appearances the internals of the lowers contained a lot of dirt

With the lowers cleaned you can place the new foam inserts.

The new seals then push into above the foam inserts, they can be a little tricky but a little persistence pays off here, its even easier if you have a large socket or something similar to push them in with.

With the new seal inserted its time to push the lowers back over the stanchions, remembering to pop the rubber band on the left leg to allow you to set the sag.

With the lower back on the stanchions, its time to fill each side with oil, each fork is different but you can use the following link to check the correct levels Fox Fork Oil Volumes.

The oil is then added to the lowers and the final step is to push them back together, again exposing the threads add the small plastic crush washers and then using the 10mm socket tighten everything up.