KTM 690 Fork seal replacement

[Cardude]

I have a 2016 KTM 690 Enduro R I bought used a few months ago. Have ridden it about 500 miles around Big Bend, Hill Country gravel roads and water, and lots of dusty gravel here around where I live in Victoria.

Rode the 150 mile “Dirty Tarply” loop from the HC 500 rally track this weekend, with lots of dusty gravel and water crossings, and when I finished I noticed my right boot was covered with oil. I found the right fork leak leaking pretty bad, like a steady drip. I’ve heard about the 35mm film trick to try to dislodge dirt from the seal, but with so much oil leaked out could/should I try that? How do I add oil?

Or should I just replace both fork seals at this point? The bike has 12k miles on it and I have no idea if the fork seals have ever been replaced. I’ve never done a fork seal job, but I watched this video and it doesn’t look too terrible, although I don’t have any of these tools so would have to buy them all I suppose.

Or should I take it somewhere to get the seals replaced?

 

[_RG_]

Doing seals is tedious but not difficult. Getting the tools is well worth the price and makes the end results way more reliable. I've even heard of folks replacing seals on a campground picnik table in Silverthorn Colorado with an excellent outcome.

 

[DFW_Warrior]

The list of tools he gave in that video is one of the better lists I've seen on a video about forks. All too often, they are listing that you buy every single tool that the manual lists out and you will be out $400 in tools alone. The only tools in his list that I would agree with him are optional are the dust seal remover and the seal "bullet". I've done dozens upon dozens of seal jobs and I still don't have a dust seal remover tool. I do have a few seal bullets in the common sizes of fork tubes but if I don't have one in a size of a fork that I am working on, like he said, e-tape works like a champ.

What I would say (full disclosure, never done forks on a KTM yet) but I would try and find SKF seals. When it comes time for seals in my 300, I will be putting SKF's in there. I haven't found any better seals than these so far.

 

[Little Stevie]

Try the seal-saver/seal-doctor/piece-of-film first, especially if the leak started suddenly.

KTM/WP forks are easy if you're accustomed to working carefully and keeping things clean as you go. Overall, it's kind of messy job, so lots easier if you have room and lots of rags or tubs--something to contain the very slippery fluid that has magical abilities to get everywhere.

Our 690s are fitted with the "split-chamber" forks ( 4CS I think I the formal designation), so right and and left are different inside. Not a problem, just have to pay attention. Like DFW---, I've redone a few forks without all the tools, though I have fabricated a few to make things easier. Nothing fancy.

I seem to recall Slavens having a good yoootooob vid on rebuilding forks.

SKF certainly make good seals. Pretty sure some KTM OEM are SKF and even if not, the OEM are very high quality. For my old 950, it was very worthwhile to buy the KTM rebuild kit; cheaper than sourcing parts separately and it provided substantial upgrades. Big thank you to Brian at TJ's for that.

 

[kubotamiketx]

If you are going to do the seals, think about doing the bushings at the same time. They don't cost much and are a wear item too.

 

[Little Stevie]

If you are going to do the seals, think about doing the bushings at the same time. They don't cost much and are a wear item too.

I'd be like K-Mike. I'd renew some o-rings and washers, too. Maybe.
Copied the following from RMATV, but I'd go to my friendly local KTM dealer as they might know something I don't. Note that both these kits have been updated since the original forks came out.

5 RP10048T
(replaces part #
R14040)
Seal kit 48mm SKF black $56.89

11 R14047T
(replaces part #
R14028)
Guide bushing set fork 48mm $24.15

 

[Dao]

I'd do both seals at same time.
wouldn't hurt to also renew bushings too.
if you're heavier than 180 lbs, good time to put in stiffer springs / or preload existing springs w/ plastic spacers/ to dial it in for your weight.
on your 4cs forks, I read on advrider that there's a free mod on the compression base valve where you flip the valve upside down to increase comp. damping. I"ve never done this so i can't tell you the results.
the 690 comes w/ the adjustable triple clamps, so this' a good time to change offset 2mm less for more straight line/interstate stability, if desired.

 

[Cardude]

I'd do both seals at same time.
wouldn't hurt to also renew bushings too.
if you're heavier than 180 lbs, good time to put in stiffer springs / or preload existing springs w/ plastic spacers/ to dial it in for your weight.
on your 4cs forks, I read on advrider that there's a free mod on the compression base valve where you flip the valve upside down to increase comp. damping. I"ve never done this so i can't tell you the results.
the 690 comes w/ the adjustable triple clamps, so this' a good time to change offset 2mm less for more straight line/interstate stability, if desired.

Thanks for the info.

Tell me more about how to do this offset change? I don’t have any pavement stability issues but would like a bit more stability when going fast on gravel, but maybe that’s just rider error on my part.

 

[Dao]

Factory setting is 32mm offset, which i think is about right for gravel, ATV , 4x4 dirt roads

but it's pretty easy to change offset:

take front fender off
now, look up, into the bottom of the lower triple clamp
unscrew the alum. silver 28mm bolt at the center
note the dot on the steering stem. if it's oriented to the rear of bike & at the no. 32, then that's the offset dim for smaller trail dim.
rotate the steering stem 180 deg. so dot is now pointed to the front of bike & at the no. 30, that's the offset dim for larger trail dim.
put back the 28mm bolt, torque it, put fr fender back on.