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1505
Joined
1/5/2014
Location
USA
Edited Date/Time
6/6/2016 12:39pm
All right, reaching out to the moto minds of Vital for some help:
09 YZ250, brake side fork seal keeps blowing, matter of fact, I'm on my third set this year. Lasts about 3-5 hours. Tried OEM and SKF and both have blown around the same time. Forks were revalved and resprung over the winter by a local suspension shop, who will go unnamed. Have 15 hours on them now and the third set just blew this morning. Forks are properly aligned, no nicks or scratches in lower on either side, bushings were new at rebuild. Brake side fork does have a tremendous amount of pressure releasing from it every time I bleed time, which is before I ride and when I get home. I am religious about keeping my bikes clean and also pop the dust seal down after every ride and clean them as well. Talked to the previous owner and never had an issue with it either.
Thoughts?
09 YZ250, brake side fork seal keeps blowing, matter of fact, I'm on my third set this year. Lasts about 3-5 hours. Tried OEM and SKF and both have blown around the same time. Forks were revalved and resprung over the winter by a local suspension shop, who will go unnamed. Have 15 hours on them now and the third set just blew this morning. Forks are properly aligned, no nicks or scratches in lower on either side, bushings were new at rebuild. Brake side fork does have a tremendous amount of pressure releasing from it every time I bleed time, which is before I ride and when I get home. I am religious about keeping my bikes clean and also pop the dust seal down after every ride and clean them as well. Talked to the previous owner and never had an issue with it either.
Thoughts?
When you pull down the dust seals are you sticking anything inside the oil seal to clean it?
What brand seals and what brand bushings are you using?
I don't think i've ever had seals blow out from anything other than wearing out through friction. There's never been a chunk missing from the inside lip, and the mysterious business card trick for dirt has never worked. Friction wears em out, increasing the I.D, and leaks happen. Excess play equals more friction and heat.
The Shop
Luxon 4-Post Bar Mounts
$189.95 - $239.95
DeCal Works Huge Plastic Inventory of UFO and Polisport kits.
http://bermmotorsports.com/collections/dirt-shock-sox
The only other thing is fork bushing worn and allowing enough flex to leak.
Sound like there is flaw in the chrome of the tube somewhere.
I would start with full disassembly and inspection of the inner chamber and seals.
Wrap a strip around the fork tube and sand a cross-hatch into the tube with the paper.
You aren't trying to take down the OD, just buff down any irregularities and put in a cross-hatch pattern.
Make sure you are assembling the front end correctly. If you pinch the fork lugs together when you tighten up the axle and pinch bolts, you're likely to have seals leaking the first ride. Make sure your axle doesn't have any burrs or dings on the end. Lots of people who don't know what they are doing use a hammer or other implement to pound the axle in. That mushrooms the end a little and doesn't allow it to properly locate in the right fork lug. If the Previous owner beat on it, get a new front axle, or use a small file to remove the burrs on the axle OD.
http://bermmotorsports.com/collections/dirt-shock-sox
Pit Row
This is the story of the motocross "industry" from my perspective. I see too many people with $2500 worth of anodized billet aluminum all over their bikes and most of it isn't as good as the OEM part it replaced.
Plenty of exceptions to that statement, but I see it a lot.
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