WP4860 Fork Service For Dummies

[Ji Gantor]

This is a modern upsidedown fork.
Should be pretty similar to a Pre 90 fork.
Any way like all forks they started leaking oil last ride so today I purchased a pair of new fork seals and a litre of 5w oil.
I already have all the tools required to service these forks.

Tight nuts

Ji

[Ji Gantor]

First turn your rebound and compression clickers clockwise to find out what your current setting is.
Then grip the fork and undo the cap with a pin spanner.

Tight nuts

Ji

[Ji Gantor]

Lower the outer tube down.

Tight nuts

Ji

[holeshot buddy]

they are nothing like the pre 90 fork ji

[Ji Gantor]

Sorry Holeshot I don't have a pair of Pre 90's to see.
I just guessed that they should be similar.
Okay these are just modern forks.
Nothing like any VMX bike including Pre 90.

Tight nuts

Ji

[Ji Gantor]

Grasp the spring and pull down so a 22mm open spanner can be fitted to the hex.
The hex has a steel plate top and bottom so when the spring is released the spanner is kept in place.

Tight nuts

Ji

[Ji Gantor]

Place a 24mm socket or ring spanner on the cap nut and loosen.

Tight nut

Ji

[Ji Gantor]

Remove the cap.
Then remove the spring and let drip into a pan.
Now we can pour all the old oil into a measuring container.

Tight nuts

Ji

[Ji Gantor]

Hi Wasp,
Yes I use Stahlwille, Snap On, KC Pro and Repco spanners.
I like the Stahlwille because they are so light and thin.

Tight nuts

Ji

[Ji Gantor]

With the spring out, the outer tube pushed down and the oil drained it is time to place the fork into a vice.

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Ji

[Ji Gantor]

With the fork held securely in a vise pry the rubber plug off the bottom of the fork.
Place a 19mm socket onto the compression cap and loosen.

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Ji

[Ji Gantor]

Now that the cartridge is free both ends we can lift it out of the outer tube and place on a drip tray.

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Ji

[Ji Gantor]

Gently pry out the mud wiper.

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Ji

[Ji Gantor]

Lever out the circlip.

Tight nuts

Ji

[Ji Gantor]

With the circlip removed the inner and outer tubes are now free.
This said they do not just come apart, you have to use the two tubes like a slide hammer.
Two or three slides and the seal will pop out of its recess and the two tubes will come apart compleatly.
Remove all the parts and place on a drip tray in order so they will go back on the way they came off.

Tight nuts

Ji