As posted by Shawn Mc.
Any questions, holler his way!!!
Re: Blown Fork Seal
Heres the quicky procedure:
Assuming the fork is off the bike...

Unscrew the large cap, dump the oil. screw the cap back on.
Loosen up the rebound adjuster nut. Holding the fork somehow (how is up to you) push the fork together and the damper rod will poke out the bottom. Snag that sucker with a 12-14mm wrench. At this point, take the rebound adjuster nut gismo off the damper rod. Its just screwed on the end and jammed there with the jam nut that has two flats ground on it (17mm). Once the rebound adjuster is removed, squeeze the fork again, take the wrench off the damper rod and re-unscrew the big cap and pull the entire damper out of the fork. Pick the spring up off the floor and wipe up the oil you just spilled too...knuckle head...

Now, to replace the seals. Use a small screw driver or a paint scraper or something really thin to pry up the dust cover on the seal. Dig the retaining clip out with a small screw driver and a pair of needle nose pliers. Once you get the clip out, you simply slide hammer the fork apart. Bang bang bang..its a part...wipe up the oil you just spilled...man your making a huge mess...pay attention to what your doing ok...jeese...

A smart guy would change the oil in the damper too. Its easy enough. Just unscrew the center of the top of the damper (entire compression clicker assembly #15 ) and then to remove that entire assembly, Slowly compress the damper rod into the damper. Compressing the damper rod will reduce the vacuum that is pulled when your trying to pull the "compression bolt" out. Once its out, just dump the oil...stroke the rod...to aid remove of fluid...get your mind out of the gutter...

Reassembly is reverse everything, assuming you understand how to install the new seals. Use a baggie or something like a baggie over the end of the fork tube when you slide the new seals on to prevent damaging the tiny edge that does all the sealing work...sux when you gotta do it again because you didn't practice safe seal...

Stock oil height in the outside chamber is 412cc (05 and earlier). Put 200 in the inner chamber. Some will burp out of the inner chamber. Make sure you pour that off/out the holes in the inner damper.
If you do both chambers in both forks you'll need roughly a quart and a half of fork oil (I use Synthetic ATF)

Anything else?

It's the same procedure for seals, fork springs, oil and any other reason you may want to take the fork apart...

I'd only add that you should do a seal sweep before you replace them because almost every leak I've had was caused by dirt in the seal. Pull down the dust seal then slide a 0.005" feeler gauge under the fork seal and run it all the way around the fork several times. Angle the gauge so that any dirt you catch will be swept out of the seal. Keep doing this until the feeler gauge comes out with no sign of dirt. Do the same with the dust seal while it's out. Shoot it all down with brake cleaner, wipe every thing clean, put dust seal back in place; done. Nine times out of ten, mine stop leaking .

What you really want to do is this. Step one. Call Shawn and tell him you are coming over to show him this trick new part your buddy made in his machine shop, hinting that you "think" Shawn is capable of reproducing this part.

Step Two. Stop at 7-11 and buy a case of Coors Light, he loves that shit.

Step Three. Tell him you forgot the trick little part at home and hand him a beer. Now that you have him drinking, forward the idea that you just so happened to have your forks in the truck with new seals and that you are dying to try his idea of Synthetic ATF in the forks and since they were apart changing the seal would easy.

Presto, new seals and fluid. Just be sure to hose his entire driveway off not just the part where the oil spilled that way you look good for doing a little extra. I always throw his rose garden a little squirt as well for good measure.

Kinda funny...I just did a guys YZF450 fork...or one leg anyway...so I only got a twelve pack...

ATF in the OUTER chambers only, right? Or is syn ATF 5 weight?

Whats the advantage of this anyways?

BK14MX said:

There isn't any fork oil police so you can put what ever you want in there. But I put ATF in both chambers. Works great. I don't get too caught up in the "what weight is it"...The only time I ever notice anything different about the fork with the ATF in the inner chamber is in the mornings. It take about a lap to warm up the fork. After that, you'd never know the difference.

since the crf's use showa twin chamber forks like my cr..i can use this procedure on my 01 cr250 right? are there any differences other then valving between the forks off a 01 cr250 and a 05 crf450?

One thing I found to aid in the process and seemed make disassembly/reassembly a lot easier was to loosen lower bolts and fork caps while forks/front wheel are still installed. Loosen the lower bolts 1st and then remove the front wheel. When you are ready to do the fork cap, loosen pinch bolts and drop the fork to about an inch below the upper clamp and snug up the lower bolts, then you can get the fork cap wrench over the cap and loosen. Once this done on both sides drop the forks off and continue.

For me this worked out much better then to try and clamp forks on a vise. Use the bike as your vice...........

punkrock MX said:

The earlier TC Showa's were basically the same. The piston diameter in the inner chamber is smaller.

hey how is it going. I am in the process of changing my fork seals on my CRF 450R and can not get the two tubes apart. The dust cover is off and so is the retaining clip. Every time I slide hammer the fork it just sticks and I have to pound it down to get it to move again. Please help.

richdawg said:

Its not a natural move to put that much force into slide hammering the fork apart, but youve really gotta wack at it pretty hard sometimes.

Youre sure you got the wire clip out from beneath the dust cover right?

I was just curious if anyone was going to mention bleeding the damper?

motofix said:

Bleeding the damper isnt rocket science. Here's what I do; I fill it with 200cc of oil. Then I S L O W L Y run the damper rod through its stroke. If you pull that damper rod too hard its going to squirt oil out the top and make a mess. Once I think Ive got it bled out, I throw a 1" wide steel rule into the damper like a dip stick. It should read 1.875" of oil. If its higher, keep bleeding. If its less add some oil because you miss measured the first time.

Pushing the base bolt into the damper can require some decent effort. Any excess oil in the damper will burp off the top. Once youve got the base bolt snugged push the damper rod up all the way the body. ALL THE WAY. It should return itself ALL THE WAY. If it doesnt, pull the base bolt and add some more oil and try it again. Dont forget to pour off the excess oil through the holes in the damper body. Youre done!


Id like to add something here and I hope I dont get in trouble with the TT gods, but that said;

If youre a local SoCal guy and want to PM me for a personalized lesson or want to simply watch while somebody (me) does your fork for you, Im good with that for a small fee. Its not a business I make money at, but I thinks its fair to get compensated marginally for the knowledge I can bestow on somebody so they can save buttloads of money. I'll charge you less than what it would cost for a seal job and I'll teach you how to do it yourself so you can the next time.

Do you use 200 cc of the 412 cc for the inner chamber? This would leave 212 for the outer. Sorry but I just want to make sure before I put everything back togeather.

Thank you

Rico

PA_Kevin said:

Soyrico said:

200cc on the inner chamber, any excess will be purged when you run the damper rod all the way in and it pushes past the piston up into the space where the ICS is. You then pour that off out the holes and the bleeder vents.

350-400 or whatever in the out chamber. The two are completely separate.

The 412cc number is the stock number for the outers when completely disassembled.

You need roughly 1250cc of fork oil to do both legs.

hey shawn

my front suspension seems kinda soggy, think freshening up the oil would help? it def has alot of hours on it..synthetic atf? you said u notice a diff in the mornings?? slightly stiffer for a lap?

punkrock MX said:

An oil change will definitley will help. In cold weather (below 50F) you'll notice the fork maybe a tiny bit for a lap.

Quote

Make sure to apply heat to the outer tube right over the oil seal and outer bushing. You can use a heat gun or propane torch, just get it hot enough where it's barely too hot to touch. And then "GENTLY" hammer the tubes apart, NEVER FORCE!!

This will let the outer tube expand a bit and the forks will seperate easily. The tolerances of the Showa componets are tighter than their KYB counterparts and require and extra measure of carefullness when disassembling. Failure to use heat will most likely cause the outer bushing to "climb" over the inner bushing and remove some of the teflon coating. Requiring bushing replacement.

Take Care, John

Thats a great point John.