CB900 Forks
Rebuild of Front Forks Honda CB900
In April, 2008, I completed a rebuild of the front forks of my 1980 CB900 Custom.This page features some photos of the process.

Before I could commence work on the forks, I had to get the bike up on a lift. The low level of the exhaust system precludes simply placing a lift under the bike and jacking it up. As seen in the photos below, I used a number of wooden blocks to ensure that the lift points were solid - the sump and the front frame cross member.
The left fork had to be removed again and it was discovered that the fork seal had a small nick in it. A new seal was ordered and the damaged one was removed. On closer inspection, it was discovered that the inside of the left fork slider had several gouge marks that appear to have been caused by a previous owner using a screwdriver to pry out a seal. The gouges had sharp edges and may have caused the nick in the seal. The gouges were smoothed out using 280 paper and fine bronze wool before the new seal was carefully installed.  This time the seal did not leak and the job has been completed.
The two photos above show the bike with both front forks removed. The handlebars have been disconnected and are resting on the tank (protected by towels). A cardboard box has been secured between the throttle and the front brake lever to prevent the brake being squeezed whilst the brakes are disconnected (thereby avoiding the brake piston being forced out).
Above:  The front forks dismantled and the underside of the rusty front fender being treated with Rusteco rust remover. Whilst the fender was off the bike I decided to clean it up.
Above: The fender after further rust treatment and three coats of aluminium colour paint.
In the photo at right:

The new Honda parts required to complete a rebuild of the front forks (from top to bottom)

Dust seal - part # 91254-KAZ-003
Cir Clip - part # 51447-461-003
Back up washer - part # 51413-461-003
Fork seal - part # 91225-461-003
Back up ring - part # 51412-461-003
Slider bushing - part # 51415-461-003
Guide bushing - part # 51414-MN4-003
Copper washer - part #90544-283-000
Gasket for drain bolt - part # 90543-273-000

You need two of each of these parts to complete the rebuild.

I also installed Progressive fork springs instead of the old stock springs.
Above:  The forks have been rebuilt and fitted to the bike. New Automatic Transmission Fluid (ATF) was added together with the Progressive springs and the wheel was refitted. Once the bike was back together, I put air into the front forks and discovered that the left fork was leaking!