Changing Fork Seals on a Honda Bros

I have a customer with a 89 400 Bros. It is is desperate need of some new fork seals. I have recently acquired some new tools for this job. This includes a depth syringe so the fork oil can be sucked out of the stanchion until it sits at an exact height. I did not end up using this I just poured in a desired quantity. I also bought a slide hammer to know down 41mm fork seals without causing any damage.

 Firstly I strapped down the rear end of the bike to raise the front wheel off of the bench.

 Pinch bolts need to be loosened before the axle can be un done.

Caliper must be removed to get the wheel out. Then the fork brace and mudguard.

I always loosen the top clamp and then loosed the fork caps, keeping the lower stanchion tight so the fork doesn't just twist. Take care not to hit the tank like I did.

The dust seal can be pried off with a chisel of wide flat head screw driver.

This will uncover a corroded C clip that slot into the fork slider. This is fairly easy to pry out using a small ended driver.

To separate the slider and stanchion the allen bolt in the bottom of the fork needs to be removed. This will be held in with loctite and so the slider should be mounted in a vice and then when an appropriate socket it fitted into the bolt it should be hit with a hammer to break the loctite's bond.

This should undo fairly easily. Then it is just a case of sliding the slider off of the stanchion, this will take a few attempts it takes a bit of force so dont be scared to really pull it off. Probably worth noting that once the allen bolt is removed fork oil should start leaking everywhere. So pop a bucket on the floor.

With the fork cap off also the internals can be removed. It is good practice to have a manual handy and to be mythodical. Its is easy to fit things the wrong way round.

 Old and new seals.

 The upper most section of the stanchion has high levels of pitting, I use some plastic sheet to protect the ID of the seal from damage.

I also make sure all of the seal are wet with fresh fork oil before assembly.

This slide hammer houses the oil seal nicely, it also pushes the new dust seal into place.

 I apply loctite the the allen bolt on assembly, the internals are just a simple clean and re-fit procedure nothing was changed this time.

I annealed the washer to soften the copper and allow it to seal once again. This involves heating it up until you see a change in colour and letting it cool slowly. The forks were filled with fresh oil and re-fitted to the bike, the owner has notice a subtle but very pleasing improvement of the bikes ride and handling.