Can you change WR400 fork seals yourself?

[CoWr_400rider]

Has anyone ever changed their WR400 fork seals themselves? Do you need all of the special tools listed in the manual? Do you really have to pull the internal cartridge apart to change the seals? Lastly for the un-informed what is WCTT, Western California ThumperTalk? Thanks for any help.

Rick....

See ya on the trail.

[Frostbite]

I've changed my seals twice, no special tools, took a few hours but nothing extremely complicated, and I used an old seal as a driver and then cut it off but you can also use a piece of plastic pipe.

[CoWr_400rider]

Thanks Frostbite. One other question. How did you level the fork oil? Did you compress the fork then fill it and level it? Thanks again.

Rick....

See ya on the trail.

[Frostbite]

I filled the forks according to the manual, I can't remember exactly but I think it's with the forks compressed. Make sure you pump the dampers plenty to get all the air bubbles out before you set the final level and measure the level, don't go by oil volume poured in. I took a zip ty and set the zip at the recommended distance from the top of the fork tube to the top of the oil. Then I rested it with the zip end on top of the tube and the other end down inside the fork and filled until the oil reached the zip ty.

Everything I read about fork oil level says it's absolutely critical to get the proper amount in the forks so I'm super careful about getting it right. If you put a bit too much in, take a straw or your overflow hose off you gas cover and draw a bit out.

I'm going out to the shop to work on my bike tonight and I'll bring the manual back with me. If you don't have one I'll post the correct oil levels for you here tomorrow.

Good luck. ?

[99wr400]

Heat the lower part of the outer fork tube (the part with the seals in it, It is bare aluminum, and has the little plastic fork guard guide on it) I tryed changing my seals, and endin up having to have my forks rebuilt, because I screwed up the "sliders" and stuff....

[Gee]

Be sure to replace the metal slide rings near the seals, they have a coating on them that wears off over time. My yamaha dealer had them in stock.

[unkle_george]

Heat the outside and put the metal inside piece in the freezer... Then it'll slip in like butter. ?

Well, almost. But MUCH easier. Also, drive in the metal ... then drive in the seal. Both at once is 10x harder.

Just changing the oil is pretty easy. If you ride in the water alot ... change it at least once a year to keep your springs from rusting.

- Ryan

[jbrooks26]

I've changed my seals twice, no special tools, took a few hours but nothing extremely complicated, and I used an old seal as a driver and then cut it off but you can also use a piece of plastic pipe.

Hey Frostbite, just curious as to how you drive the seal. Looking at your pic, it looks like you used the outer tube to drive the new seal. Is this right? If so, how do you keep from damaging the dust seal? I spent about 45 minutes driving my first new seal with a piece of plastic pipe and a hammer and thought to myself that there had to be an easier way. Anyway, thanks for all of your input.

Josh

[Frostbite]

I installed the new seal and then slipped the old seal on above it and used the outer tube like a slide hammer to tap it in. A couple of light taps and it slipped right in. Then I cut the old seal off.

Looks like I may have popped another one today, my right seal is leaking. if cleaning it doesn't work I'll take post some pics of the replacement job.

[5valve]

please check your PM's frostbite

[jbrooks26]

I installed the new seal and then slipped the old seal on above it and used the outer tube like a slide hammer to tap it in. A couple of light taps and it slipped right in. Then I cut the old seal off.

Looks like I may have popped another one today, my right seal is leaking. if cleaning it doesn't work I'll take post some pics of the replacement job.

Sounds good. I never thought of that, I guess what they say is true. Necessity is the root of all invention. Thanks Frostbite.

Josh

[CoWr_400rider]

Hey thanks for the info. Frostbite. One last question. How did you get the tubes appart without the tool to take the cartridge/damper apart? According to the book you hold the top of the cartridge/damper then remove the compression valve at the bottom of the tube. Can you pull the slide out without first removing the cartridge/damper? Okay that was two questions. Thanks again for all of your help.

Rick....

See ya on the trail.

[jbrooks26]

If you are only changing the seals you don't need to take everything apart. All you need to do is separate the inner and outter tube. Just make sure that when you put it back together that the Jam nut on top of the dampening rod is seated correctly. You won't be taking this nut off, but on mine it either didn't get done at the factory or it worked it's way loose. I didn't find it until I went to return my settings to stock and the dampening screw on top of the fork almost screwed all the way into the fork. About 10 turns too far. Now I have to take it back off and fix that. Anyway, sorry for my rambling. All you need to do is drain the oil, pull the dust seal, pull the spring clip that holds the oil seal in the fork, and then use the outter tube like a slide hammer to pull the old seal out. The two tubes will now separate from each other. The manual shows you how to rebuild the whole fork, and if you are just changing the seals and you don't see any other problems when you get into it then there is no reason to tear the whole thing down. Hope this helps and I hope it makes sense.

Josh

[Frostbite]

I've changed my seals 2ce now without any special tools or trouble. When I changed my seals the first time I didn't have the manual so I just kept unscrewing things until they came apart. I didn't run into any problems or need for special tools, and I stripped mine completely apart and washed everything out. Maybe I got lucky but I just unscrewed the allen keys in the bottom of the fork legs. I took them out first so maybe the spring pressure helped hold the damper rod. ?

The only slightly tricky part I remember was finding a thin wrench to hold the nut just above the spring, and then holding the spring down so I could get at it. Snap off wrenches are slim and may fit but I just have Mastercraft and they were too thick. I had an old adjustable wrench that was flat enough to fit perfectly.

When I put everything together I had to pump the dampers quite a bit before air bubbles stopped coming out, a lot more than the recommended 10 times. You can kind of feel the foamy bubbles as you move the rod. When all the air is gone you get a smooth steady feel.

A seal started leaking yesterday. If I have to replace it I'll document everything carefully for the other tool challenged do it yourselfers out there.

[CoWr_400rider]

Hey thanks for your help. I wondered why the damper had to be pulled apart. I have changed fork seals in older bikes but this one having inverted forks an damper it was kinda new to me. Thanks again.

Rick....

See ya on the trail.

[CoWr_400rider]

Hey thanks again Frostbite. As I told Jbrooks I have changed fork seals in older bikes the inverted tubes on the new bike were a little different. Thanks again.

Rick....

See ya on the trail.