125-200cc Leaky Fork seals

[BCdirtbikegal]

My WR150 had a leaky fork two months ago (about 100hrs on the bike then) and had the seals changed/forks serviced at the shop. Now they are leaking again, not as bad but still leaking. I have cleaned them a lot and that hasnt helped so looks like I need to replace the seals. I figure I should learn to do this myself rather than paying a shop. Any tips on doing this?

 

[Blakelpd5]

I don't know what forks came on the 11's, so I can't help you there... But when you tear them down, I would look real closely at the stantions for scratches... I installed 2 sets of seals & wipers before I realized my stantion was scratched...

 

[Dirtdame]

You probably have the same 48 Kayaba forks on yours that I have on my 300. I had about 6 weeks on my new bike when it blew the left seal. Not just a little....it poured all over my front brake! That was on a Thursday, and I had a ride with an out of town guest planned for Saturday!. Friday, I found a genuine Yamaha seal (also the same size as many other models Big Four brands) at the local dealer for $12.99. Not too hard to change out seals, but you will need a split seal driver and an oil level tool to do the job as simply and nicely as it can be done.

Remove the fork from the bike.
Unscrew the fork cap. Compress the fork and the spring and rod will come up. Remove the cap from the rod. Remove the spring. You may want to remove the the little rebound adjuster rod from the rod assembly too, because it'll fall out anyway. Empty the fork oil into a container, then grab the rod and slowly push it in and pull it out till the rest of the oil is purged from the lower cartridge and runs out of the top of the fork tube. Now you can pull the wiper, remove the clip and give a few good yanks on the tube. It should come right out of the top part of the fork assembly. You can remove the bushings and spacers, carefully laying them out in the order that they came off in. They have to come off to get to the seal. The end of the tube has some really sharp edges where the bushing are seated that could cut your new wiper and seal, so I like to run scotch tape around the tube to cover these sharp edges during reassembly to protect the new seal. (don't forget to remove the tape once the wiper and seal are on the tube!) Reassemble in the order that you took it apart and use a split seal driver to drive and seat the bushing, then use it to seat the seal, and finally for the wiper. You will need to know the oil level. Stand the tube up and completely collapsed to full stroke, and fill it all the way with the proper weight of oil, let it stand for about 5 minutes, then pull the damper rod up and push it down to bleed all the air out of the lower cartridge until it is completely smooth in both directions. You may have to add more oil to achieve this. Then you take the oil level tool and set it for the specified level and draw out the oil that is extra. Put the spring back in, put the rebound adjuster rod back in, cinch the top cap to the rod and tighten the cap back into the fork assembly. Takes about 45 minutes. That's it in a nut shell. It was the same for the Zokes on my TE450 too.

 

[Joe Chod]

true to check for knicks and knacks. fine emery...very fine

sad fact is dirt gets in

thhey are dirt bikes

sometimes gets in in a week..sometime takes months

the nature of the beast

 

[huskybear]

I use "seal savers" on all my bikes and they greatly extend the life of the fork seals especially in muddy conditions.Just my 2 cents!

 

[BCdirtbikegal]

Thanks Dirtdame your one leak where it went all over the front brake sounds like my last one, it poured out all over. huskybear, I'm going to try the seal savers, seems to be mixed info, but a lot of people use them especially in muddy conditions it seems, so I figure it can't hurt with two leaks in a few months.. worth trying!

 

[jo360]

you can make your own seal savers using a felt strip between the seal and the scraper just collects the dirt that gets past the scraper and replace regularly.

 

[zilly]

There are some pretty good tutorials on youtube about this. I know they helped me do mine, always nice to have pictures. Also, since I didn't have a seal driver I saw somewhere about using the old seal cut in half (use a hacksaw) and lay the old halves on top of the new seal. Whack with a rubber mallet (gently) until seated. I am sure the seal driver works better but that worked for me.

 

[ohmygewd]

Front brake side always leak due to tiny bits of brake dust mixed with dirt that can get caught up on the stanchion which digs away at the wiper plus the twist or flex caused by braking.
There are heaps of seals out there and to add to Dirtdames post, take your time bleeding the air out and lay out all the parts in the order you took them off.
Write down your settings as you should back off all the adjustments before stripping.
To loosen the cap, keep the fork(s) in the triple clamps but loosen the top bolts then loosen the caps - harder to do off the bike if you don't own a vice.
Invest in a seal driver and fork oil level tool - just makes life easy.
Pay attention to fork oil height as this will determine the air gap and WILL effect your ride.
Don't need a seal bullet, electrical tape does the job in protecting the seal on installation.
Always clean stanchions with some 1200 grit sandpaper and use wd40 or sawing machine oil as a lubricant - insures that small nicks are smoothed out...and sand up and down too.
Clean seal savers regularly and pull down the wiper and give that a good clean as well - there products on the market that can clean under the seal and l highly recommend Rhinomx seal doctor......or you coul use an old goggle lens.

Changing seals are, in Australian slang, a piece of piss .... Tuning is another story

 

[BCdirtbikegal]

Another rookie mechanic question... went to start this tonight, and reading a bit more online it mentions one reason forks can leak is due to improper fork alignment after mounting the front wheel. When I removed the wheel tonight, the axle on the right side is showing wear. Last tire change I did it myself and basically just put it back on and tightened the bolts. So, with it not leaking badly, rather than changing out seals, if it's all clean and I remount the front wheel with proper fork alignment this time, is there a chance that the leaks could stop?

 

[ohmygewd]

Yeah the way l do it is to tighten the nut with the pinch bolts loose. Once the whole axle spins,l tighten up the pinch bolts and then use a torque wrench to properly torque the axle nut.
When the forks leak, they leak....try using an old goggle lens and slide it up the seal and slide it around as it may clean some debris which may cause the leak.

 

[BCdirtbikegal]

Yeah I was using the camera film or 'seal mate' (like a goggle lens) with lots of brake clean, and it's helped. Just wondering though if I get the wheel aligned properly if that will help. Might just try doing that and see how the next ride is before replacing the seals. I picked up a set of the long fork skins as well, so can get those on.

 

[ohmygewd]

Improper alignment is really caused by people overally tightening the axel nut and then the pinch bolts so what happens is that the forks ever so slightly tapers to the fork bottoms.
You can check this yourself after you've installed those fork sox's by taking the caliper off, mount the wheel, tighten the axle, if you have the easy pull lever thingo that stops the axle from spinning just be sure to have it at 3 oclock and tighten until it just touched the fork leg. Now, spin the front wheel (you need a crate or bike stand too), whilst spinning, tighten the the axle nut...you should be able to see the rim slow down with resistence each time you tighten the axle.
Summary: Tighten axle nut, free spinning wheel, tighten pinch bolts, spin dat wheel and then tighten the axle nut keeping an eye that that rim is still spinning and there you go, fork's aligned

 

[slo rider]

Here's a good article on how to make sure your forks are properly aligned
http://www.moto-pro.com/files/shoptips/fork_alignment.pdf

 

[BCdirtbikegal]

Okay I am taking the forks apart to do the seals, any tips for removing the fork caps/bolts (upper and lower) tried with them on the bike and gave up. Going to borrow a vice and impact wrench and see if that should do it.

 

[Dirtdame]

Loosen the fork caps while the forks are still on the bike. Loosen the top triple clamp bolts only for this. Once its turned out a few turns, you can loosen the lower triple clamp bolts and remove the forks. Once the forks are out, you can finish removing the caps. They will still be attached to the damper rods. Fit a wrench onto the locknut that you can see between the spring coils just under the cap, then you can get a wrench or socket on top of the cap and break it loose. Impact is best here.

 

[ohmygewd]

Make sure the open spanner or socket is tight and a breaker bar or pipe to give you leverage...please don't use a shifter (adjustable spanner) here as the caps are aluminum and soft, filing down a 19mm fork cap down to 17mm is a real PITA!!
PS..open up the bleed valve too...discharge any built up pressure!!

 

[utopia]

Loosen the bolts on the top triple clamp before you try to loosen the cap.

 

[lankydoug]

I don't think anyone has said this yet, (it's in the video) make sure you back the clickers all the way out before you start taking the forks apart. Count clicks so you can go back to the same settings when you are done.