One ride, and now forks leaking....

[Rider1958]

Has this happened to anyone else?
2014 WR450 I bought as a new leftover, I only put 5 trail rides on it.
Then installed a new 2016 Timbersled long-track, rode it once for about 3 hours.
Was getting it ready for second ride tomorrow, and see what appears to be a layer of fork oil under each fork on the top of the ski.

Geez - after ONE ride! Forks were NOT leaking before first snowbike ride.

So I'll ride tomorrow and then put new fork seals in, but...after one ride!?!?

Any ideas, comments, suggestions, insults y'all might have?

 

[Sketchy Red]

While you are doing the seals put in the heaviest springs you can find for your wr. You are probably riding in the bottom of your stroke and bottoming against the fork clamps. I had similar problems with my kx450f and heavy fork springs helped the seals and my wrists.

 

[Rider1958]

Good idea Sketchy, it did feel heavy in the front - I didn't put those two together. I think I could consider a different weight fork oil in addition to heavier springs to help stop bottoming.

I had hit a few rocks in the snow, nothing too bad, but thought that might have somehow caused seals to leak.

 

[summitboy]

What kind of seals ?

 

[SteepNdeep450]

Could run a set of these...
https://www.rockymountainatvmc.com/p/1049/47066/SKF-Fork-Mud-Scraper-Kit

Also check your tubes over for some knicks but if you say there is just a little line around like an inch down from the seal, you could try and clean them out maybe they got some dirt into them. Usually you'll see them drip down the fork leg if they are leaking.

 

[TheHilltophood]

Fork Alignment

One issue I've had with both my TS front ends is trouble with fork alignment. When I tightened everything down the forks were either pulled together at the bottom (2010 YZ 450) or pushed apart (2015 KTM 300 XC-W)

I needed to bend the spindle a bit / machine down the fork clamps in order to get everything aligned.

I would suggest something like this -> https://www.motionpro.com/product/08-0412 to double check that your fork tubes are properly aligned. If they're not aligned, you're going to keep wearing out your seals.

 

[rocky Mountain snow bike rent]

leaking front seals

Believe it or not the main reason for your seals leaking was more than likely ice build up on your forks. The best fix for this problem is to get a set of neoprene fork covers and yes rebuild with heavy oil and springs, thanks ROCKY Mountain snowbike rentals.

 

[Wheel House Motorsports]

I always mod my fork covers now so i can run them in the snow, snapped one off and noticed my fork with no cover was leaking slightly. I would be willing to bet its from ice pushing the seals out because as soon as i got a new cover on, no more leakage. On really cold/icy days.

on WR/YZ fors you can just not put the inner bolts on and just sorta deflect the coverts and they will stay on just fine.

Bottoming should not cause fork leakage. the bottom forks seals you can see are dust/snow/ice wipers, the inner seal does almost all of the sealing. Although, good fork setup makes snowbiking a LOT more fun/easy.

 

[CATSLEDMAN1]

leaky yamaha fork seals

1. your fork seal issue on a new bike set up for the snow is either a bad out of the box fork seal that needs replace under warranty, very unlikely.

or

2. most likely when you assembled and put together what ever brand of of front ski mount, when you tighten up the asssembly you have pulled the fork tubes together and put stress on the fork tubes/ sliders and that will for sure cause instant and constant fork seal leaking. Check for more threads on thumper talk on this issue as Yamaha has had issues with this for years because the correct way to tighten your front axle bolt is often a mystery and if the axle doesn't float correctly you will have some fork deflection and seal leaking and 100 seals later it will still leak.

2. you need to keep fork seal grease/lube or good synthetic all temp grease under your fork wipers at all times. And riding the snow 16 hours a week, more lube more often. New seals dry will often leak.
So.......take screw driver and carefully pry down the outside dust wiper seal and brush good lube on the for tube between wiper and seal assembly and tap seal back into place.

3. cold weather/ cold snow, constant snow flow and normal bottoming will not affect fork leaking on a snowbike if you have a good set up( free moving non binding tubes and sliders ).........well ok on WHITE POWER / Kayaba / SHOWA its not an issue, other brands I don't know. On dedicated snow bikes my observation is seals will last 2 to 3 times longer that seals operating in a dirt application.

 

[Rush44]

Some people don't realize that there is a specific way to mount the spindle to the forks so that you keep the forks true. Follow this procedure to make sure they are factory straight:

1. Loosen the axle nut to hand free turn
2. Loosen the squeeze bolts on the axle shaft
3. Loosen the fork clamp bolts to hand free turn
4. Get on the bike and do a half dozen to a dozen full fork strokes jumping on the bike.
5. Tighten squeeze bolts on axle shaft FIRST (I tighten mine beyond the factory specs)
6. Tighten fork clamps
7. Tighten axle nut last (don't over tighten this one, a quarter turn beyond hand tight it usually fine).

This will allow you to be sure the forks are at least not bowed out or in which will cause seal issues for sure and possibly trash your fork internals.

 

[David24]

Same issue with me, I was thinking it was ice build up on the top of the fork clamps.

 

[KTMDigger]

Fork tube mid-alignment

After replacing the springs, and replacing the fork seals (4 times), the problem with my setup (500EXC KTM) ended up being a tolerance problem with the mounts. I had approximately 0.100" of "outward" force on the fork tubes. This was enough displacement to cause the seals to leak when bottoming out the suspension. I machined 0.050" off the face of each bracket that allowed the fork tubes to come back into algnment... All is good now.