|Posted on Friday, June 15, 2018 - 12:39 pm: ||
2009 XB12X about 36K miles...
Back in 2015 I rode from Hollister, CA to Mesquite, NV. This was in late September so not really to hot. When I got to Mesquite I noticed that the right front fork was leaking, some oil had dripped as far as the rim. Mileage was around 32K miles.
When I got back home, I got the tools needed and replaced the bushings and seals. A few months later, they were leaking again. Replaced the seals a second time rode in the area, leaking again and replaced the seals a third time this past spring. Leaking again. Note, using parts from St. Paul HD and HD fork oil, type E.
Frustrated, I started looking for an expert. Doug Chandler in Salinas was recommended by two of my sons. Doug had set up suspension for one of my son's SuperMoto race bike.
I asked Doug to have a look at my Uly forks. This is what he found...
--fork seals were installed upside down
--factory recommended oil level seemed to high in his experience. But he did set it at 114 mm from the top of tube.
--fork sliders (tubes) were in good shape, replaced the bushings with new ones I provided although the ones in place were in very good shape.
He went ahead and did the fork service with the new parts I supplied. He used BelRay 10w fork oil.
He recommended that I remove 3 oz of oil from each fork and try it.
I have reassembled the fork on the bike after removing 3 oz of oil from each and reset the suspension settings. Hopefully will get to ride later today.
I used the FM instructions to replace the seals. The FM says that the spring in the seal should face the dust seal. Doug said that is wrong and showed me the wipers on the seal. He has rebuilt a lot of Showa forks.
Any thoughts from the group on the oil level or fork seal?
I'll post me riding impressions soon.
|Posted on Friday, June 15, 2018 - 02:05 pm: ||
On a lip seal, the spring faces the oil.
That is a LOT of oil to remove, why does he think thats a good idea? Oil will be against that seal no matter the level.
|Posted on Friday, June 15, 2018 - 04:41 pm: ||
The stock seal has a lip and spring on both sides. The manual says the "marked side" faces the dust seal.
Has it always been your right side that leaks? That seems most common.
There is a trick to clean out debris from under the seal lip, using a thin piece of plastic. There is a tool that you can buy, or you can make your own. It slips under the lip, and you slide it around the circumference, to pull debris out.
I've had the right side develope a leak twice. Replaced the seal the first time, the second time I got it cleaned out, and it is working so far.
Now my left fork is leaking. I'm attempting to clean it out (with a home made thin plastic tool), but it is still leaking, a little.
|Posted on Friday, June 15, 2018 - 04:44 pm: ||
@ Shoggin.. good to know on the seal. That is just the opposite of my FM, it says spring toward the dust seal.
Chandler was concerned about actually getting some hydraulic pressure on that seal with the high level. He says Showa forks on dirt bikes and street bikes don’t run that much oil. There is enough oil at the lower level for the shock mechanism to provide the damping needed.
My observation, fwiw, any oil against that seal has been splashed over the top of the center tube and is no longer used by the fork. There is no provision for that oil to return to the center tube.
|Posted on Friday, June 15, 2018 - 05:02 pm: ||
@ Arry My FM, for 2009 XBs all models specifically says “spring toward the dust seal.”
I have one of the seals in my hand, the marked side is opposite the only visible spring.
The right side first, at about 31k miles. After I fixed it, both leaked, (fix it until it’s broken.)
I have one of the tools from Motion Pro, I think it is called seal buddy. I tried that on each set of seals when I saw them leaking.
|Posted on Friday, June 15, 2018 - 05:27 pm: ||
My bad... Mine is an '07, I wasn't thinking about the updated suspension.
|Posted on Saturday, June 16, 2018 - 12:05 pm: ||
I thought the only difference between the years was the diameter of the lower section of the fork. Larger bushings and seals but basically the same. Well, there is the offset on the axle hole too.
On my 06 it was also the right fork that leaked and here's my theory. With the caliper attached to the right fork it twist that fork causing it to wear the bushings faster. As the bushings wear, and your dust seal gets hard from age, it allows fine dust and sand etc. to get past it and to the seal causing the leak. Cleaning the seal out may stop the leak but as long as the dust cover can't keep dust from getting past it you might be getting another leak. I'm a big supporter of fork socks to keep the dust out. Cheap insurance IMHO. As far as fork oil level, the specs are about the air in the system, not so much the oil. The more air the softer the ride as air will compress and oil won't. I put the 07 springs in mine and used the 07 oil level. My problem was that the adjusters didn't seem to make much difference, it rode harsh no matter what. I ended up putting AMSOIL 5wt. fork oil in and then the adjusters actually did something! Now it's dialed in for a nice soft ride yet with a couple of clicks I can firm it up for canyon carving when I need to. When you,re in Illinois with 11 curves in 318 miles it's not very often!
|Posted on Monday, June 18, 2018 - 06:10 pm: ||
The air space above the oil works as a highly progressive spring. As the fork compresses, air pressure goes up. This helps smooth things out on very rough surfaces and also helps to reduce bottoming. The size of the airspace is controlled by the oil level. On really long forks, you need a lot of oil. Changing oil height is a component of suspension tuning.
|Posted on Monday, June 18, 2018 - 09:24 pm: ||
@Mark_weiss Thanks for the input. Chandler wondered about that.
I rode about 80 miles this weekend. I thought it felt a little “softer.” I’m going to put the 3 ozs back in each fork. The good news is that forks are dry, no leaks!