Why did my fork seals blow? ('01 CR250)

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#1
'01 Cr250
took the forks apart, put in .42 springs, changed the outer oil but not the inner chamber oil, put in 370 cc Maxima (slightly less oil than stock)
forks worked great for several rides

then one started weeping a little

now after yesterday, they are both severely blown (you know how it leaves a puddle wherever you park it)

air is bled regularly

I do bottom occasionally when I ride, but this shouldn't blow seals!

There should not have been enough dirt behind the wipers to cause a problem, I cleaned that all out when I had them apart.

What's the deal? Anyone had bad luck with the Maxima oil?

As a side note, on a KX100 (with forks way to soft for an adult) I added fork oil until the forks were actually hitting a wall an inch or two before the bottom of the travel. They wouldn't bottom no matter what! Think of how much pressure I created there, and still not as much of a slight weep from the fork seals. I don't get it.

Any other cr250 owners out there having the same problems? I just got the bike new this spring, by the way.

Thanks in advance for your help...
 

marcusgunby

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#2
i bet you have dirt behind the seal-very few seal blow these days unless the tubes are damadged-check yours.
 

Jeremy Wilkey

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#3
MP,
As Marcus said you will find that the problem is not your bike or oil, but dirt in the seals.. I'll bet your a little over zelous with the powerwasher.
Regards,
Jer
 

DKT735

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#5
I had my 01 CR 250 since Aug 2000 and changed seals this spring. I seem to have to change seals every 6 months or so on my 2000 and my 1997 CR250. I change fork oil about every 3 or 4 months so it's not that bad. I'd go ahead and change them. It doesn't take too much time. The damper rod stopper tool makes the job easy.


I'd think about changing the inner chamber fluid as well. I used to only change the outer fluid too but found out that I got better results by changing both.
 

Jeremy Wilkey

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#6
MP,
I'd change them but, you could theroretically just clean the seals and be fine. I've done it in a pinch, but I would not recomend it.
Regards,
Jer
 
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#7
is it possible that I damaged the seals with the inner fork tube if I slid it too far when I had the forks apart? I never took the seals out.
 
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#8
I have found only a few seals with obvious failure sources. Often you can clean them and get them to stop leaking but... for about $15 you could have just bought new ones and been sure. It seems like theres nothing better to ge an old set of seals to leak then an oil change. I don't know what it is but it happens alot.