Fork Seal Strategy

[Hillclimb#42]

 I have to see what you guys are doing to preserve fork seals and their lifespan. I have never been the guy that jumps the highest or lands the hardest, but it is frustrating to have a good day of riding and then to realize that a fork is leaking. Its downright expensive to blow both sides in a ride. I rarely have a shock problem, but too often am replacing seals. I'll start with what I do, and maybe you guys can pitch in some different things, to get a bigger picture for everyone.

  First, I replace bushings in a set of forks that leak in one ride or without cause.

  Second, I use a 2x4 between front tire and underneath side of front fender during transportation. That way the strap is not pulling down on the forks.

  Third, I make sure both sides are adjusted to the same settings.

  4th, I occasionally bleed off the pressure with the fork vents.

Mabe something I am doing wrong, in theory, is only redoing a side that is leaking, which may cause a slight embalance.

 Is there any thing I can do doing a fork rebuild to help the life span? Does anyone use a lubricant other than fork oil to lube the tubes? Do you pull the dust covers after every cleaning and remove debris? Any favorite brands of seals? Does thinner oil with stiff settings, or thich oil with soft settings make a difference? 

[kwakman]

I have seen a shock type dust protector for the shock on some bikes, maybe that would help at the back? Like a big shock sock.Do you use a power washer near the seals? These can play havoc with seals, bearings etc.

[DoldGuy]

42,
What fork oil level are you running?
DoldGuy

[Hillclimb#42]

Having 5 to deal with, I always run right in the middle of recommended levels. i always ran 7wt in Bel Ray oil, but now am using Lucas oil. It comes in 5, 10, 15, so I went with the 10. I bounce around with different seal brands. i have noticed some have a spring deal that wraps the dust seal and others that have no spring. Would a higher level or lower level help. I am confused, if more oil would be more cushion against bottoming or would be more internal pressure?
 kwakman, I have only had one rear shock leak, ever, and it was starting the 500 of all ways to blow it. I do use a power washer to clean them. You think some kind of protector for washing? I was thinking maybe mud dries inbetween the dust seal and oil seal, then the first bump you hit, you have a hard crispy chunk that sticks in the oil seal.

[DoldGuy]

42,
For the very short amount of time that you run the "Air" in the chamber would not have time to heat up & expand to pose a problem if you are bleeding them every other run or so. It sounds as you already know the basics but just in case: New Dust Seals, No nicks in the sliders (Chrome Tubes), both Fork Bushings in good shape, Springs correct for your weight, Fork Oil Level (amount down from the top of the tubes collapsed) correct? Years ago I had the same problems with my KX with 43mm Tubes, the cures for me was I stepped up the spring rate & lowered the fork oil level (more room for the air before it pops a seal) replaced the cartridge rod bushing (if this is worn the bottoming cone is ineffective) & probably the most important part was I cleaned the Sliders before EVERY ride. A buddy that does suspension work also recommended the Honda seals  also because he felt they had better QC than Y, K, or S and he had better luck & would always use them. I also power washed my bike after each practice & every moto & would slide down the dust seal and clean, reinstall with a little bit of grease to capture anything that got in.
Hope some of this might help!
DoldGuy

[RoostDaddy]

Have you used a seal saver?  I've had my forks leak without any problems other than dirt getting in there.  Put a "Seal Mate" up in there and run it around, may stop leaking without having to replace anything. 
Maybe this isnt your answer, but its saved me more than once for not having to replace seals that were still good.

[jonny500]

roostdaddy, i have herd of seal savers but never seen one or one for sale. where can they be purchased

[kxpegger]

http://www.motionpro.com/motorcycle/partno/08-0356/

[suicyde]

Keep in mind that most fork seal leaks are due to dirt in the seal, unless a fork seal is dry and hardened, it can usually be cleaned by pulling down the wiper (the first seal you see) and sliding a goggle tear off between the seal and the fork leg clearing out the dust or dirt.

Your air spring should be set to atmospheric pressure every ride. unscrew the bleeder when your forks are still cold to let air out or in. It makes a huge difference. 5mm of fork oil makes a huge difference too, it can be felt throughout the stroke. Its a great tuning tool.

[Hillclimb#42]

42,
For the very short amount of time that you run

    I do play ride the 250, which is the leaker. Yeah, you are always very helpful, how do you order the honda seals? Which omodels interchange? No other brand preferences? It has stock springs and I'm about 165. I doubt it's a spring deal, but maybe.

  I have used some 35mm film negatives that have worked as the "seal saver", or a laminated business card. its hit or miss it seems, but I will try again.

  5mm of oil makes a big diff? Then, I wonder, if its important to inspect fork oil level even when I get the seal cleared of dirt. Once it has leaked during the ride, on the trailor then in the garage waiting on me to get parts, there's no tellin' how much has been lost.

  So, if I add a step during the bike wash, I should be good? That being: Pull the dust cover down, clean and lube oil seal.


We used to use Pledge on the rods of the Foosball game that made them spin fast. I have also used Silicone spray lube that seems to work well. Would there be something like that, which might make the inner tube super slick?

The only thing visually wrong, is that there is some oxidation on the small inner rod. I don't think that would have an affect on the seals. I am just sick of fixing them. Its not like I am racing super cross on it. Know what I mean?

[bigbellybob]

small nicks or scratches on the inner fork tube will make it impossible to keep seals from leaking. its also very common to nick the seal during installation. i use that food rap stuff the wife has in the kitchen and rap the fork tube and bushing before sliding the seal over it to prevent damaging the seal.

i have had great results with these seals.
http://www.synergyseals.com/
 

[don46]

Kyle,

I'm going to throw in my .02.

I've seen countless fork seals leak due to mis alignment, what do I mean? If your axle does not slide into the forks easily you can force the fork to one side causing side load on the seal. anybody that has to use a hammer to get the axle in has issue. I keep my axle and the fork super clean and have made a tool that fits in the end of the axle so I can rotate the axle in without binding the fork. I'm not a proponent of the "take it off the stand and bounce on it theory" and while it may be better doing it than not, remember
Cleanliness is next to godliness, take the time and make sure the axle moves through the forks freely, grease it up and twist it in, and your golden. Motion Pro makes a axle alignment tool, I have one but really have only used it for demonstration purposes to show people what i mean by alignment.

I usually change oil on the race bikes frequently, and the play bikes at least once per year and always new seals, invariably if you don't replace the seals and just change oil the fork seal will leak and you've wasted the high dollar fork oil. 

On another issue, and how I think your riding your bike, I wouldn't go over 5 wt oil, I use alot of 2.5 and a fork oil by reline called "like water".
http://www.motionpro.com/motorcycle/partno/08-0412/

[cbmoor]

Once I have dissmantled a set of mx forks and cleaned them ready for assembly I always rub the fork legs with wet very fine emory paper Not in a up and down direction but around the tube direction and this cleans and removes any slight nics or smooths out any nicks which causes seal failure. You see a very fine haze affect on the chrome of the forks. I do not rub for ages and ages just enough to clean and smooth any nics thats been put there by racing with other bikes. And its a very fine emory cloth thats wet with oil. To be honest I have used the same piece for a while now that only used for this purpose. Its about 20mm wide and 200mm long and I loop it around the leg so when you hold the 2 ends and work it, Its all around the fork leg. Doing it this way the very fine scratches are in the same direction as the fork seals so it does not leak but it hold oil that is wiped by the seal and it lubes the seal also. If you do it in the other direction up and down the fork leg the same direction the way the forks move you will just damage the forks and they will leak!!. I am not saying this is the correct thing to do but it works for me and the many other bikes I have done.

[BDI]

One thing I find blows seals that no one has touched Is your fork springs and comp settings. If your springs are to soft for your body weight and or your setting are to soft you will be pleauged by blown seals.

[Hillclimb#42]

Don, I always unscrew the axle from the fork and screw it back in. I keep the axle very clean and greased, and it slides right in without a hammer. I have wondered if my 2x4 between the tire and underside of the fender that I am using to help tie down the bikes without the stress being put onto the forks, might be causing stress or misalignment of the seals during transportation. Do you use something like that?

Brian, it was mentioned that stiffer springs and lighter oil might do the trick, but it's all stock and should be the right rate for me. I make sure that the fork doesn't bottom out by keeping an eye on the fork tube during breaks. I usually have 6-8" of travel not being used.

Bob, I use electrical tape or duct tape to fill the bushing groove, so the seal is not hanging up on on the sharp edges. I'll check those seals out.

Thanks for everyone's input...just trying to be thorough