Let's talk about (yes): Fork Seals

[Purplehaze]

Alright Katriders,

Getting my tires swapped out, so I'm currently dismounting my rear and then will do the front. During the front tire swap I also plan to tackle the slow seeping out of my Fork Seals.

I've looked thoroughly over Black_Peter's video tut, various threads, and online resources/tuts. Still a bit unsure as to the process.

Firstly, I understand I'll have to get the tubes fully off the bike. Pry carefully under the dust seal and slide it off, then tackle the grooved clip. Fully remove the top end, drain the fluid. Then take out the bottom bolt inside the axle-run. Then hyper-extend the fork and break the seal.

Do I have to tackle the rest of it if all I want to do is replace the oil and dust seals? I intend to take a peek at the bushings while I'm there but I do I need to fully disassemble the forks if all I want to do is use the old seals to drive in the new ones?

Also, I'm still unsure as to how to measure the fork oil. How much, how to measure? Various sources showed different methods and reasonings for different levels.

As always, thanks in advance Katriders.

[92xjunker]

If your changing the oil and seals, why not completely clean and inspect them properly? You can just change the seals and oil but, what's going to be left in there when new clean oil is added.

[mammut89]

the easiest and safest way to get the oil seal out without damaging the stanchion is to completely take out the stanchion by punching it a couple of times outwards and the oil seal follows it out. And once youve done that every part is out and can be inspected. I dont know how you are planing on taking out the oil seals otherwise...

so basically there is only one way to do this

[Kreylyn]

Just a couple of things...

1. If you don't have access to an impact wrench, loosen that bolt on the bottom holding down the damping rod BEFORE you take them fully off the bike. Otherwise, it's a real pain in the arse. If you have an impact, it's no problem to do after with that.

2. Fluid is going to be aprox 16oz each, but... what you would do to get exact is reassemble partially including the new seals, but leaving the spring and top spacer out. With the tube compressed, measure from the top of the tube lip to the fluid level. Should be 110-115mm depending on how stiff you want it.

3. Be absolutely sure when the tubes are off that you roll them on a flat surface and verify they are straight.

4. You do really want to go ahead and do a full disassembly and cleaning to remove the old rancid oil. It's going to be nasty stuff if the forks have not had the fluid changed in a while.

5. Make sure you have space to lay out parts as you diassemble the forks in order, in a long line of how they go back together. Makes the process really easy to keep up with and not miss putting something back in.

Krey

[Purplehaze]

Mammut, that bit was the hyperextending the fork to push out the seals.

You gents make a fine point about all the rancid oil. If it's on the run with everything the previous owner left it's probably NEVER been done. Thanks for the info on the measuring.

[raidinmd]

bumpin with a new question, i'll be replacing my seals and oil soon as well, I know the book says 10w but anyone else run something different for good reasons?

[92xjunker]

15 here with a full racetech suspension, weeeeeeee

[raidinmd]

yeah, not gonna shell out for that, my forks have been seeping since I got it last year lol, I wish I had the money =\

[rschlegel]

, I'm still unsure as to how to measure the fork oil. How much, how to measure? Various sources showed different methods and reasonings for different levels.

As always, thanks in advance Katriders.

Motion pro makes a fork oil tool. It is just a syringe with measurements on a metal tube. You set a ring at the correct level and when you can't suck out any more it is at the level you set. It makes it easy to get both forks to the same level.

[92xjunker]

Or get a measuring cup and pour in what the manual says to.

[raidinmd]

Or get a measuring cup and pour in what the manual says to.

exactly. it tells you exactly what to pour in, buy a cheapo ruler and convert to get the right measurement.

[Purplehaze]

Suggest 10w without RaceTech. I can't guarantee 10w was what was in the forks before but the front end feels a million times better after the new seals and oil. I used the end of a micrometer that sticks out when you extend it to measure 110-115mm from the lip of the fork fully compressed. The damper settings have much more affect now as well so it's adjustable as needed.

[Aaron-71]

Suggest 10w without RaceTech. I can't guarantee 10w was what was in the forks before but the front end feels a million times better after the new seals and oil. I used the end of a micrometer that sticks out when you extend it to measure 110-115mm from the lip of the fork fully compressed. The damper settings have much more affect now as well so it's adjustable as needed.

Have any info on where you got your parts/kit from?

I'm thinking I should be doing mine after reading up on how bad the oil can get... I think I've got OEM oil in my 05 Kat forks...

[Purplehaze]

Youch. IIRC I sourced mine from EBay. I used the All Balls Fork and Oil Seals kit. Put plenty of miles on them so far and no complaints (was even towed nearly fully compressed after my bike was knocked over by a drunk guy, hit quite a few famous St. Charles potholes and still haven't gone).

That said, a few members here advised me after the fact to not use the kit and go OEM seals only.

Get a piece of PVC pipe that will slide over the tube (Don't quote me on this but I think 1/2 is the correct size).
Can source these through a home improvement store pre-cut, good size and easier to haul if you have no other need for piping. Some members here made modifications to their PVC pipes to make them slide inside the lower stanchion to drive the actual oil seal. I suggest instead that you take all the seals you have and just stack them up and give it a few good whacks. if you do this the very first old oil seal you stack ontop might get stuck down there -- CAREFULLY (are you reading, CAREFULLY) use a dentist pick or small flathead to get it out.

The fork oil I used was Bel-Ray Fork oil. Everyday Powersports store ought to have some or once again, E-Bay it.

A micrometer from anywhere, Harbor Freight can be cheapest.

The lower dampening rod bolt can be the bear of the forks. Take a 6mm Allen Wrench and notch of the short end with a hammer and knock it off them file it FLAT. It'll fit right in a 6mm socket and be perfect to apply proper torque for the bolt to get it loose and later.

[Kreylyn]

All balls fork seal kits work fine. I've yet to have a set go bad/leak on me, and I've used them in all most all my bikes.

Avoid "no leak" seals like the plague... they don't leak, they spew....

There is a whole thread with detailed break downs of what fork oils work best. Tmod did a bunch of research and posted this. Might wanna do a search for that.

Krey