What weigh fork oil for 2004 Harley fatboy and how much in a oil change out no seal replace

To change the fork seals in a 2004 FXD you will need to remove the forks from the bike and then drain the oil and then remove the dust seal and the retaining ring and spacer from the top of the fork and then remove the Allen head screw from the bottom of the fork to release the fork tube and then using the fork tube like a slide hammer drive the upper bushing, seal and spacer out the top of the slider. While apart you should also inspect the rings and bushings etc. You will need a special seal driver to reinstall the upper bushing, seal and spacer and then you will need to accurately refill the fluid to the correct level/amount. FXD/FXDL uses 10.6 OZ or 0.31 cc of Harley-Davidson TYPE E FORK OIL (Part No. HD-99884-80) and the level measurement is 6.69 inches or 169.9 mm. Be very careful and accurate with the oil level as too much or too little will adversely affect the function, ride and steering of the bike. It is best to use a fork oil level gauge and set it so that the ring will sit 6.69 inches or 169.9 mm from the end of the tube and secure it at that position. If your gauge has a plunger cylinder on it push the plunger on the cylinder all the way in and then with the fork tube bottomed in the fork slider, insert the tube until the ring rests flat on top of the fork tube and pull the plunger out to suck up excess oil from the fork tube. If no oil is sucked up into the gauge cylinder you need to add more oil until there is enough excess oil in the fork tube to have an excess amount sucked out of the fork tube. In this manner the gauges and cylinder will accurately set the fork oil level. If you have a vacuum operated gauge such as with a tool that attaches to a vacuum brake bleeder you will set the tool at 6.69 inches or 169.9mm as with the other type of tool and operate it the same way to remove excess oil to a precise and accurate specified fork oil level which is very important as an incorrect oil level can adversely affect motorcycle handling.

To replace the front fork oil first support the motorcycle so the front end is off the floor and the forks are fully extended. Remember that the FLSTC and FLSTF models have a preloaded fork spring and that the fork tube plug is under spring pressure.Then you remove the fork tube caps. And then you drain the fork oil. ON FXSTD models, your remove the drain screws and washers from each fork and drain the fork oil this way. ON ALL MODELS EXCEPT the FXSTD, remove and discard the drain screws and washers from each fork and drain the fork oil and then you install new drain screws and washers. ON FXSTD models, apply LOCTITE THREADLOCKER 243 (blue) to the drain screws and tighten them to 12-18 inlbs (1.4-2.0 Nm). ON ALL MODELS EXCEPT FXSTD, tighten the drain screws to 52-78 in-lbs (5.9-8.9 Nm).THEN fill the fork with Harley-Davidson TYPE E FORK OIL (Part No. HD-99884-80).Either by installing oz or cc's of fluid if the forks were left in the frame or by measuring the amount of oil in the tubes in inches or mm if the forks were removed from the frame and disassembled. In the latter case the oil level is measured from the top of the fork tube with the spring removed and the fork fully compressed.

MODELs FLSTC, FLSTN use 13.4 OZ 395 cc4.41 inches 112.0 mm
MODEL FLSTF uses 13.4 OZ 397 cc5.04 inches128.0 mm
MODELs FXST, FXSTB, FXSTC use 12.5 OZ370 cc 6.69 inches170.0 mm
MODEL FXSTD uses 11.6 OZ343 cc 7.48 inches190.0 mm

FINALLY tighten the fork tube caps to 40-60 ft-lbs (54.2-81.3 Nm).

I have an '04 Fatboy and work in a dealership. Swapping the oil tank is not fun! There is very little clearance for tools and your hands! If you decide to try it yourself, get a service manual. It will make the job a little easier, with the steps you need to take to remove the tank. Or, get a service manual and read how to do it and decide if you want to tackle this job yourself.

When was the last time the fork oil was changed? Has there been any leaks? Loss of oil will cause the forks to go soft.

If you ask this question YOU should not be doing it! but your *** on the seat not mine.
Remove ...........front wheel, front fender,top fork cap and loosen lower triple clamp bolts under head light cover, forks are now out!
Remove 6mm bolt at the bottom of the fork leg and drain oil,remove dust seal and wire clip, now remove the upper fork nut (the spring will jump out at you).Pull the leg and tube away from each other, the old seal will stay on the tube..clean and reassemble driving NEW seal down into place with wire clip.....refill with oil

ten ounces in each side . Make sure they are drained completely to avoud overfill

change the oil seals and oil in the fork,and avoid wheelies on the bike and off road biking 

Either the seals were not installed correctly or your tubes and sliders are excessively worn. Not changing the fork oil at recommended intervals will cause excessive wear. Overfilling the forks will cause leaks too.

Specs for a FXSTC is 10.2 oz

for FLSTC its 11.5 oz

For your year bike use heavy duty fork oil