major fork oil leak :(

[psyklone393]

this is a total bummer. i just got a chance to replace my clutch basket and clutch boss and while i was wrenching i figured i'd take care of a minor fork seal problem. at gmb3, jaswhitt812 pointed out that i had some oil streaks on my fork tubes. so tonight i busted out the trusty ol' film trick. once that was done and i put the wipers back in place, i hit both fork tubes with a quick shot of brake cleaner and wiped them down to clean them up. the very bottom of my left fork had a pretty decent accumulation of thick 'stuff' on it that i hadn't noticed because of the fork guards. i gave that a second shot of cleaner and wiped all the way around that 'lip' with the shop rag and then put the fork guards back on and thought i was all ready to roll.

wrong.

as i was putting my tools back up i noticed a small pool of fluid on the rim of my front tire. when i touched it i knew it was fork oil ... and it was leaking out fast. i took the left fork guard off real quick and expected to find the oil coming from the top of the tube where i ran the film around. but it was coming up from the bottom of the tube where i had cleaned that residue off of. initially i figured that residue was a result of a little bit of oil that made it down from the small leak at the top seal, however clearly there is something very wrong at the bottom of the tube. it was leaking so fast i could hear the tube sucking air one time as the oil poured onto the garage floor. i don't understand it, though, because all i did was clean the tube. :

does anyone have any clue how big of a pain in the arse this is going to be for me to fix? my first impression is that there's a blow seal on the bottom, however i really don't know at this point ... and as i recall, a special tool is required to get the bottom of the fork tubes off.

grrrrr,

-Z

[Macho393]

Would these be the same forks as on a02 250f?

[Macho393]

no special tool to take apart .But you will need to make a seal driver. Check out Motoman's web site. I believe he has a pic of one he made. This is if they are like my 02 forks. A litle hint b4 you install the dust covers back on, pack with some white grease

[psyklone393]

they aren't the same ones exactly. the part number for the '02 yz250f is 5SG-23102-00-00 and the part number for my '99 yz125 is 5ET-23102-00-00 ... however they look very similar.

-Z

[Macho393]

If you got a manual, its not a problem. Just follow the steps. I know you can do it. I did mine with no help. Not a problem the whole time. Im left handed too!

[pragmatic393]

Bummer, you were planning on riding this weekend too.

I'm still a little lost on were the leak is comming from?

[Jim X]

Yeah that really doesn't sound good at all, if I get what you are saying. It's not leaking out of the fork seal so much as it is the bottom of the fork, but still on the tube right?

I am pretty sure I have the exact same forks and when I had them apart to do a seal, it looked like the inner tube was pressed into the axle "boss", or whatever you would call it. So, in essence, all ONE peice. I am at a loss as to where the leak would be coming from, unless it is running down the back of the inner fork tube, hidden from view. If the fork oil is relatively new then it will be pretty clear so this "could" be happening. Tie or wrap a rag a little ways down from the tube of the inner/lower tube and see if it collects the oil.

But, as far as I know, if it isn't leaking out of the fork seal, then you are in a world of hurt, you must have a hole or have seperated the innertube from the axle "boss" somehow. I've never heard of that happening, but I would say that it "is" possible.

Sorry I can't be of more help. I have an '00 yz125 for reference.





EDIT: I guess there could also be one other thing, the bottom "grub" type bolt could have come loose, if it didn't fall out, be very glad.

[psyklone393]

the leak is definitely not coming from the top fork seal. since i just cleaned the fork tubes, i can feel all the way around the inner tube and it's dry. the oil is coming up from the bottom of the fork tube where it mates with the axle housing. i'm still at a loss as to exactly what happened because it was fine until i cleaned it, and as soon as i did the oil almost literally started pouring out.

-Z

[Jim X]

Well the mixture/suspension os dirt in the oil was probably stopping it from leaking more. It was probably leaking way before you ever cleaned it, but then as soon as you took the crud off, it exposed the opening.

Is the oil coming from the bottom of the axle housing or the top, where it mates/is pressed onto the fork tube?

[psyklone393]

it's coming from the top where the tube is fitted into the housing.

-Z

[Aus_Rider_22]

For those who can't quite picture the situation I went and had a look at my bike (00 YZ125) and took some pics of what Zack is talking about.

I put some arrows on where I think Zack is talking about.


On this second pic this is what it may look like. That is just some washed off cleaner that hasn't dried yet on my bike.


Hope this helps. I hope I am thinking of the same thing as you, Zack.

[psyklone393]

thanks geoff. yeah, that's where i'm talking about.

-Z

[Jim X]

Looks like you have a case like what is laid out in your sig!

I say that if you are sure that where it is coming out of, take it all apart because it is going to need it anyway, the sooner you take care of it the better you'll feel. But I wouldn't neglect any riding buddies that you have, have em take a look at it and see if they can come up with a better summation. But, my bet is you are going to have to take it ALL apart, down to the bare inner tube, and seal it somehow. I'm not sure how, welding may work if you have a good stainless welder around, maybe there is some type of sealant that you could buy that would seep in the crack/hole with capillary action.

One word of caution though, check it throughly for cracks, remember it's your *** if it breaks!

If it is just leaking through where they are pressed to gether than a type of penetrating sealant may be what the doctor ordered.

Either way though, I'm guessing it will need a thorough teardown to take any action against the leak.

Let's hope it's a relatively easy fix, if not, don't get too discouraged you'll iron it out somehow, even it you do need to buy a new inner tube...AHHH!



Edit: Aus_rider great pics!

I have compiled a couple links for what I think could help you in this situation, if you want to check for cracks you will need some good visible dye penetrant and developer to show the cracks, and cleaner to prep the fork leg.

[Only registered and activated users can see links. ]

If you want to go that way then you will have to dissassemble the whole fork leg/drain all oil, and clean it up real well, as the fork oil would render that test useless if there was a tube full of oil pushing the dye penetrant out.

I had an idea for using a sealant that uses capillary action to penetrate any crack that may be letting oil out, you would also have to dissassemble the whole fork for this method because of the oil pressure. Using green thread locker, I will look to see if there is a better solution but this may be a way to do it.

[Only registered and activated users can see links. ]

Also you may be able to use a wicking type/thin CA glue that is used for hobbies to seal the space between the axle housing and forktube. Basically thin super glue. Fork would need to be completely assembled/cleaned for this too.

[Only registered and activated users can see links. ]


Hope some of that helps.

[psyklone393]

thanks jim x. i'm about to get into it right now. i'll let you know what i find.

-Z

[psyklone393]

well ... i'm stumped. i pulled the fork off and put a little bit of oil in it to see if i could pinpoint exactly where it was leaking. none of the oil leaked. i put some more in and pumped the tube, but still no oil leaked out. i went ahead and filled the fork to match the volume in the other fork and got everything mounted up and put back together. even after grabbing the front brake and bouncing the front end up and down, everything looked good. i went ahead and took the bike out into a field behind our apartments and rode it for a few 'heat cycling' sessions because i just put a new ring in. still no leak.

:

i'm thinking that i torqued something wrong previously or something wasn't seated right before. i have no clue what happened, but whatever it was appears to be fixed now. i'll know for sure tomorrow when i take it to the track.

-Z

[Jim X]

Good to hear! Now, let's hope it stays that way.

[McCracken21]

Hey Guys I've got a question. I've got a '97 YZ 125 and it has oil leaking from above the fork cover. It looks like it could be from one of the top seals but I have no clue how to fix these. Any advice or links to how-to-fix this problem is much appreciated

[MotoMan]

-Z

I hope you got it, but if you run into further problems, PM or E-mail Shocknut he can talk anyone thru anything.

Good luck brother and let us know how it goes.


McCracken, check you other post.....