Josh125

Member
Nov 8, 2006
5
0
Hello, there is something wrong with my forks on my 1987 RM 125..Every time I jump or hit a rock they make a loud bang like there trying to extend to much and smashing against what ever is stopping them from coming apart. The fork seals have been leaking since I got the bike...Would having no fork oil cause this problem>? Am I damaging the forks by riding like this? Thanks -Josh-
 
Nov 21, 2006
37
0
Josh125.Would having no fork oil cause this problem>? Am I damaging the forks by riding like this? Thanks -Josh-[/QUOTE said:
The answer to those two questions are yes,and yes.I hope you haven't already damaged your forks.Hydraulic pressure provided by the fork oil is what keeps the forks from topping out.Your bike will be a lot more fun to ride with a controllable front end,too!

It's an easy job to change the seals.On most dirt bikes,it's a half hour job,once you've done it a couple of times. Get a manual for specifics to your bike,but basically you drain the oil,then raise the front wheel completely off the ground,and take off the front wheel.
Then remove the fork caps.Make sure if there is any spring tension on them that they don't fly up,and hit you in the face.
Lift the springs out,then unscrew the bolt that holds the slider to the damper.It's usually right at the bottom of the fork,sticking straight up.Sometimes it's covered by the drain plug,or some other cover(check your manual).
At this point,the sliders should come right down off the stanchions(tubes).
The seals are in the top of the sliders,some bikes have a snap ring here,above the seal.If so,get a pair of snap ring pliers. Otherwise,getting that snap ring out,then back in again will be the hardest part of the whole job.

Now is a good time to check the stanchions,and sliders for scoring(which is likely,since you have been riding it around without oil)If the scoring is light,you can usually clean it up with some emery cloth,or a surfacing disc.If it's heavy scoring,not much you can do but replace.

Anyway,pry the old seals out with a tire iron,or screwdriver.Put a rag between the lever,and the slider,so you don't gouge the top of the slider.Try not to distort the old seals too much,so you can use them to drive in the new seals.
Clean and crud from around where the seal sits,then smear a thin coating of non hardening gasket sealer(like #2 Permatex)down in the top of the slider,where the seal goes.This will lube the seal as it goes in,and hold it firm once it sets.
Make sure you have the seal right side up.Tap around it evenly, make sure it goes in perfectly straight.Some people use a board to tap on,but to me,that just gets in the way.Once it is flush with the top of the slider,use the old seal to drive it in the rest of the way.Make sure it is completely seated.

In the infamous words of the Haynes manual,reassemble fork in the reverse order of disassembly. :laugh:

Whew! That's a lot more detail than I started to go into,but still not enough.You need info specific to your bike.

Listen,if this is more hassle than you want to do,at least go down to Wally World,and get some cheap ATF and pour that in your forks.Yes,it will leak out,and be messy,but your forks will work better.And,if you keep hammering at that top stop,it's going to break,and your forks are going to fall off. :yikes: I've seen it happen more than once.

:cool:
Cheers!
Bruce
 

gthoma23

Member
Apr 24, 2008
86
0
haha, sorry to laugh but i had the same problem a week ago...and i think i found the problem. i changed my fork oil, and broke one of my compression damping screw. just so happen that it broke when it was all the way out. and me bein the idiot i am, thought i should put the rebound all the way out to compensate. well, i was wrong. my suspension was slammin so hard i thought it was gonna fall off. so i decided to put the rebound screw all the way in. and it fixed the problem right away. i do have a question though, do u think i blew my fork seal by riding like that? cause my forks never leaked before, or is it just a coincidence?

Thanks, and hope it helps!!!
 
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