Front fork leaking oil from bottom of the seal.

cOULD LEAKING FORK SEALS CAUSE FRONT BRAKES TO FOUL? -- YES
You shuld get a manual, you must check the surface of the fork, if there are scratches, you will destroy a new seal.

YOu can but it will just end up leaking out in a short matter of time.

forks need to be removed,and disasemble,and cleaned,new fork seals,reasembleb fit new seals, refit damping cartridge,fill fork with 5w fork oil upto 120mm from top,refit spring, refit fork cap

There is a seal in the "slider" of the front fork, the part that moves up and down. I haven't had a chance to work on the later forks but the earlier 41mm forks are quite simple.

Start by taking the drain plug out of the bottom of the slider and work the slider up and down to blow out all the oil. Then, remove the front wheel. Remove the top cap from the upper tube and loosen the top plug. Now, with the top plug loose, loosen the pinch bolts and slide the fork out of the triple trees. Remove the top plug carefully, There is a BIG spring in there. Once you have the plug out lift the spring out and set it asside. Notice the tapered end of the spring. It goes back in first. Turn fork tube upside down and allow as much oil to drain out as possible.

Now, look at the bottom of the slider where the axle goes. Up in a hole there is an allen head bolt. it is designed to use a special wrench but a regular 8mm allen key in GOOD shape will take the bolt out. It's best to use an air wrench to do this with. With the bolt out, the slider should slide right off.

Down inside the top part of the slider is where the seal is. Theres a snap ring, a spacer, and a seal. Replace the seal and put a little oil on it to assist reassembly. Put everything thing back together and add the appropiate about of oil. Since your forks are much larger than mine, I have no specs as to the quantity. The owners manual should tell you or a call to a local Harley dealer. Sorry but thats a good as I can do. There is a "wet" measurement and a "dry" measurement. Since you disassembled your fork, use the "dry" quantity of oil

it s something you can do yourself if you're mechanically inclined and pay attention to detail. there are some special tools you need, such as a fork spring compressor, fork seal driver, and snap ring pliers if you don't have any. the internal parts in the fork must go in the same way they came out, and all parts should be cleaned prior to reassembly. you should also consider replacing the bushings along with the fork seals and dust covers. might really want to consider letting a professional do it so that way the forks still don't leak after you put in the new parts.

Hi,

I was told by many people it was a hard job.
I didn't think so.

What you need is:
New Seals.
8mm Allen Key.
Half Inch Stocket bar AND Extender.
Extra Fine Sand Paper/Polishing Device.
Fork Oil + Measuring Jug.
Threaded Bar with a Two 19mm Nuts Locked to each other on one end.
Spanners.
Screw Drivers.

How to do:

First Get the Front end off the Ground (ALOT, Center Stand on Bricks for extra height.)

Remove Front Wheel and Brake Calipers.

Open Drain Philips Screw on Base of Fork (Both Sides). Dont Lose Rubber washer under screw. Watch Out Also for Oil Being under Pressure.

Remove Nut from TOP of Fork (Alowing Handles and mirrors to come loose).

From Top you can see down tube has Nut/Cap with a Square Half Inch center. Use Socket Bar (and Extender if needed) without Bit to Remove reach in and remove. Watchout for Spring Pressure under the Cap/Nut.

Use Screw Driver or Hook of some kind to remove Preload Spacers, Washers AND Spring from Fork.

Slide your Threaded Bar with19mm Nuts (Make sure they are Locked Tight together at one end) down into the Fork and let it catch on the Oil Damper at the base. You will know when it's cought because you wont be able to spin the threaded bar anymore. This will stop the Damper from spinning while you undo the Allen Bolt at the very base under the fork (Outside).

Use Allen Key to remove Bolt from Underside of Fork While having someone or somthing hold the Threaded Bar form spinning.

Now look at the Old bust/leaking Oil Seal. There will be a Clip/Locking Spring in a Groove holding it in place.

Remove Clip without Damaging any part of clip or fork.

If Everything above was Done, you can now give the slider( Bottom Part) a big tug and it will all come lose.

One Part of the Oil damper will either fall off, or be left in the slider(Bottom Part). It slides over the Damper in the base of the tube.

Clean Everything.

Clean Again.

Polish Tube.

Clean Again.

Remove Two Split Washers from base of Tube and Copper Washer. Remove Old Oil Seal.

Place New Oil Seal on Gently.

Replace back on Copper washer, followed by two split washers.

Use Grease as a kind of glue to hold the part of damper that fell off back on.

Slide Slider back onto Tube.

Screw Allen Bolt back into base of slider as per originally was (Remeber to hold Threaded Bar if it starts spinning)

Push Gently new Oil Seal into Fork Slider for Snug Fit. Be Gental.

Replace Clip/Spring over top of Oil Seal Locking it in place.

Remove your threaded bar from top of Fork.

Replace Spring into Fork.

Replace Philips Oil Drain Screw into base of fork (Dont forget Rubber washer).

Now: For a GT550 (I am told also KZ550 but can confirm) you need 300ml of 15 weight Fork Oil. EACH Fork. So a Total of 600ml whole Job. IN EACH SIDE YOU WILL ADD ONLY 300ml of FORK OIL. (15w)

After this. Replace any washers, Preload Spacers and so back into for.

Replace Cap/Nut into Fork Tube with Socket Wrench and Extender.

Replace Handles and Moirrors and Nut holding both of these.

Replace back onto bike the Front Wheel

Check Brake Calipers for leaks and Pad Wear. It's Very Cheap to get new Pads. Not cheap to have months off work after a crash.

Replace back onto bike Calipers.

Pushing Bike (Not ride) test Brakes and Suspension.

At This point I am thinking your done. You may need to Add Air Preload into the Fork via the Air Valve. 4PSI is a Starting Point. I have run upto 15psi. Without Air in the Preload you may find it too soft. Upto you.


Did I Forget Anything?

you need to rebuild your forks new oil seals and dust covers

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

Yep, drain the fork oil, raise the front wheel in the air, remove the front wheel and axle. The nut to remove the lower leg is at the bottom, hidden by the axle. If it still leaks after seal replacement your fork tubes and lower leg sliders are worn out. Reassemble and remove the top fork cap. Pour in the correct cc of fork oil and ride.

You just needed to.... remove front wheel, support bike on something, undo retaining bolts on forks, tap out fork legs from the top, using a soft mallet. Take out fork seals with a seal pick, (halfords) Replace old seal with new seals, in reverse order) sliding over the fork leg, tapping into place. Then put replace forks etc in reverse order (from dissassembly). Hope this helps