01 WP 43 USD fork disassembly procedures?

[KTM400EXC#232]

In need of specs and procedures in order to change my fork seals, 600 miles and leaking seals already.
Any help greatly appreciated.

Thanks in advance.

This seems to be a common fault?

Tom

 

[smilinicon]

Common only to those who don't clean their seals.

Clean the inside of the wipers after every ride with a piece of film or thin plastic. You can do the same to your seals to stop the leakage. If the tubes are scratched by the dirt, use Crocus cloth to polish them up. I also run a rag behind the fork protectors often to clean where I can't see. WP forks are pretty good about not leaking.

Ounce of prevention...

The WP forks are very simple to work on if you do need to change the seals.

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smil

 

[drehwurm]

Servus KTM400EXC#232,

As said above the forks are easy to work on -standard procedure like on the Kayaba forks with one difference: there is no tool to hold the cartrige when removing the base valve. An air gun will work fine though.

If you don't have an air gun, before starting to disassemble the forks put some pressure on the fork (put it in a vise up side down and load the spring) and a wrench will work to LOOSEN (not remove) the base valve. Start disassembling the fork like normal and later on it should be no problem to remove the base valve.

This seems to be a common fault?

Why? No more than on other forks!

Michael




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[KTM400EXC#232]

Michael, once I have the spring out, is the next step to air impact out the base valve?
Will this allow me to slide out the lower fork leg in order to change fork seals?

I am determined to do this myself.

Thanks in advance.

Tom

 

[WhiPit]

KTM400-

NO, removing the base valve will NOT allow you to separate the inner and outer tubes to replace the seal.

Remove the dust wiper from it's seat. Under that, there is a circlip - remove the circlip from it's groove and take the back-up washer with it.

Now, with the oil drained (unless you want a big mess) and the fork cap and spring removed, you "slide-hammer" the inner and outer tubes apart. That is, grab the outer with one hand and the inner with your other hand and yank the two in opposite directions. The seal and the bushings will come out with the inner tube.

You don't necessarily HAVE to remove the cartridge. I'd also be careful removing the base valve with an air wrench, if you decide to do so. I think KTM sent out a bulletin about base valve removal on these forks.

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[drehwurm]

Servus Tom,

This is a great link:
http://www.karlstrommotor.se/bilder/wpis.pdf

Notes: I always remove the cartrige when changing the oil or seals - the debris in there won't come out completely without removing. If you are carefull with the air impact (short bursts, push down on the cartrige from the open side) it shouldn't be a problem.

To answer your question: The cartrige/piston rod limits the extension of your forks, the circlip abouve the bushings holds it together if the cartrige has been removed!

Michael



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[Jeremy Wilkey]

This should help.. Sorry but this is a quick cut and paste for this purpose..

Instructions for 2814 valve installation:

Disassemble forks completely:

Valving components.
-Remove fork cap.
-Remove spring.
-Taking a 19mm socket (Impact style) and a impact wrench remove the base valve assembly. (Apply downward pressure against the fork rod using a clean towel. This insures that the valve is moves outward as apposed to the valve pushing the fork cylinder out.) Use short bursts and not long durations of RPM as this can damage the components.
-Remove the fork cylinder.

Seal and tube dissembnly:
-Using a subtle blade (Flat but small screw driver) remove the dirt scraper. Don’t pry as it may mar the forks appearance.
-Using a smaller blade remove the circlip that holds the seal in place.
-Heat the seal carrier or the portion of the tube uniformly so as to facilitate easier bushing removal with out damage.
-Using quick but not forceful hits drive the tubes apart. (Speed is more important than force and never yank at the end of the stroke.) Use the quick momentum to drive the tube off. Failure to do as described above often results in bushing damage.

Internal component disassembly:

Fork cylinder:
-Unthread the oil lock spring guide from the rod using shaft blocks. Drop the rod out the bottom of the forks being careful not to damage or lose the piston band.
-The nut holding the valving components has been staked from the factory and needs to be ground flat past the edge of the stake to remove the nut and separate the valving and piston. (Prior to the grinding process pack the orifice with grease to prevent grinding chaff from entering and being lodged in the internals.)
-After removing the stake the edge of the nut needs to be radiused of its metal bur that develops during grinding. (This bur may come free during fork use and causes numerous problems.) A polishing wheel such as cratex works very well and leaves an excellent finish. Be very careful to maintain proper shim and piston orientation during removal. Also note that may times small spacer shims are placed under the post spacer, or valve these are easily misplaced and will dramatically impact fork performance.
-Now that all the components are free of the stem radius the first thread to prevent thread wear during reassembly.
-The passive valving (base-valve, or foot valve) needs to removed. The nut can be just turned off on these model forks. After the nut and valving has been removed you will need to radius the first thread in the same manner as the active stem. Proper orientation must be maintained to insure the components are assembled properly.
-Wash and clean all components thoroughly before proceeding any farther.

Assembly of fork tubes.

-Place the axle bracket in a vise and firmly tighten down.
-Placing a bag over the tube lube the seal and install the dirt scraper. (Remember that seals always work with pressure so if orientation becomes unclear use that as your guideline.) Install the circlip, oil seal, backup washer. With round edge toward the seal. Bushing outer and then bushing inner. (After the oil seal is installed remove the plastic bag.)
-Use a 43mm seal driver to drive the seals and bushing into the seal carrier. Install the circlip and then install the dirt scrapper.

Assembly of the Active compression and rebound damping.
-Build the stacks specified and then install them on the stem. By very careful not to misalign any washers or components as they could be permanently damaged by doing so.
Double check all components for proper assembly.
-Tighten the nut down after a small amount of blue loctite has bee placed on the threads. Make sure that the nut is not lose or over tightened, clean all components with compressed air to blow off any extra loctite.

Assembly of the Passive compression valving.
-Install the valving components on the base-valve stem add a drop of blue loctite to the threads. Tighten the nut down firmly but do not over or under tighten. If your revalving build the necessary components and stacks.

Installing internal components:

-Place and align the fork cylinder in the tube. Grease the base-valve threads and piston o-rings. Using downward force to the rod place the base-valve in the axle bracket and tighten the valve. Once the threads have been engaged use your impact wrench to finish the job. Tighten in firmly, using quick short bursts. Long and high speed rotations are damaging to the components.
-Place the fork upright and fill with fluid. Let the fork oil settle into the gaps between the tubes by refilling every few moments or until the level stops falling. At this point thread the fork cap on the rod 1 to 2 turns and lift both the outer and inner tube to full ht allowed by the cap. Quickly compress the fork full travel. That should initiate fork bleeding. Refill the tube and bleed the rod by stroking up and down until the action becomes consistent and smooth.
-Set the oil ht by measuring from the fluid level to the edge of the fork tube.
-Double check the jam nut tension on the rod. Do this by firmly holding the rod in your hand and tightening the jam nut down as hard as possible. (Do not ever grasp the rod in anything other than a holder.)
-Extend the rod completely and lay the fork over to a 45 degree angle. Quickly and precisely slide the spring down over the rod. Place the fork cap and bottoming components on the rod.
-Holding the rod with your thumb and index finger tighten the cap down till it seats on the top of the rod. Then insert a thin 21 mm and tighten jam nut up to the fork cap. Firmly tighten jam nut to fork cap.
-Bottom fork cap to the tube but do not tighten. The top triple clamp is responsible for keeping the cap on.

Check for improperly placed rods during rebound clicker setting. Compare the depth of screw in fork cap left and right when rebound is full hard. (This is a quick test.)

Reset your clickers and enjoy!


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"Danger is one thing but danger combined with long periods of suffering is quite another." Sir E. Hilary
wilkey@mx-tech.com

 

[Murf]

Damn! I just paid Holeshot $37 for the WP fork manual linked to above in drehwurm's post, and then Jeremy gives step by step instructions. I hope no one else falls for that. $25 for the manual, $6 shipping, and $6 for using a credit card! At the time I didn't know where else to go for the manual.

If anyone wants to buy a copy, I will sell them for $20, and I will pay the shipping! ;)
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Murf
Y2K 300EXC

[This message has been edited by Murf (edited 04-09-2001).]

 

[KTM400EXC#232]

Thanking everyone for their help.

Now I can get my hands dirty.

Cheers
Tom



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go on, brake late, my mum does!

 

[jeb]

Originally posted by Murf:
Damn! I just paid Holeshot $37 for the WP fork manual linked to above in drehwurm's post, and then Jeremy gives step by step instructions. I hope no one else falls for that. $25 for the manual, $6 shipping, and $6 for using a credit card!

How did they justify the $6 CC charge? They pay an extra 4% or so on CC charges but that'd only be $1 on the parts in that order.


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John Brunsgaard - JEB
01 KTM 400 EXC
99 KTM 250 EXC
99 KTM 200 EXC
98 KTM 125 EXC
98 KTM 380 MXC (gone)
96 KDX 200

 

[Murf]

The $6 credit card charge is their "standard procedure". I saw a post on their board one time about it. They provide a good service, and the board, and they have stuff in stock but, $25 to make some copies and put them in a folder is a little steep.

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Murf
Y2K 300EXC

[This message has been edited by Murf (edited 04-10-2001).]

 

[PT564]

Ok,

Two things. NEVER take your suspension apart with out the proper amount of beer! You risk it being a terrible experience without it.

2nd, stay FAR away from Holeshot. If Old Dale is drilling people for $6 CC charge you should go elsewhere.

PT

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[Murf]

Let me correct myself, I believe the second $6 charge was for "handling", not for using a credit card.


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Murf
Y2K 300EXC