How to Change the Fork Oil in a Harley Ultra Classic

by Jim Murkot Sr.
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The telescoping front forks on a Harley-Davidson Ultra Classic motorcycle are filled with Type E Harley fork oil. This oil will become contaminated over time, even during routine riding conditions. As such, the oil needs to be drained and replaced with fresh, new oil. Harley recommends that the fork oil on an Ultra Classic be replaced after every 20,000 miles. There are two factory-recommended procedures for replacing this oil. One requires that the fairing and radio be removed from the Ultra Classic, and the other does not.

Step 1

Remove the core from the front fork air valve located on the right rear of the motorcycle using a valve stem remover. Allow all the air to bleed out of the system.

Step 2

Unscrew both large drain plug screws located on the bottom of each fork with a large, cross-tipped screwdriver. It may be necessary to use a hammer-operated impact screwdriver to accomplish this.

Step 3

Drain the oil from each fork into a suitable drain pan. Clean up any spilled oil before proceeding.

Step 4

Reinstall just one of the two removed drain plugs. Attach an air suspension pump to the air valve for the front forks. Gently apply pressure to assist with further fork oil drainage. Disconnect the pump when fluid no longer drains from the fork.

Step 5

Attach a vacuum tool to the air valve. Pour 9.7 oz. (287 ml) of Type E fork oil into a small container. Run a battery vent tube or other suitably-sized tubing from the container of fork oil to the open drain hole.

Step 6

Turn on or actuate the pump long enough to draw all of the fork oil into the front fork. Reinstall the drain plug and repeat for the opposite side.

Step 7

Screw the core back into the air valve with a valve stem remover. Pump in small amounts of air with the air suspension pump to achieve your desired amount of fork suspension.

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