Anybody know what the average cost of doing fork seals would be? If I took the forks off and brought them into a shop would that be best? I'm very mechanically inclined but have never attempted anything like fork seals. Is it really that hard? What would I need? I think I may just be a little scared because a friend had a botch job done on his seals and had one blow out on him.
Oh yeah, it's a 1980 Yamaha XS 400.
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Hiya Stratus, I'm going to move this to the garage section - but I'll leave a shadow topic here for you.
Swapping fork seals is actually a pretty easy job. I just completed 2 sets of forks in the last 2 weeks, so it's funny you should bring the topic up. The actual seals usually run in the $20 range. Oil might be another $5.
On a BMW, and some other bikes, you can simply drop the lowers while the uppers are still clamped into the triple clamps. The problem is, with Japanese bikes you almost always need some kind of special tool to run down into the fork tube and hold a bolt tight in order to separate the stanchion (Smooth upper) from the (lower) aluminum tube. For this, you must Drop the complete fork.
If you have a manual for the bike it should detail which method you need to use. In addition, having a firmly anchored soft-jawed vice (With a rag) helps speed things along. (For the special tool method)
Actually replacing the seals isn't a big deal. Just be extra careful when you put the seals on the uppers- you don't want to cause the lip of the seal to roll. You can use a silicon or soap-based grease to help you get them on. Sometimes I use a cigarette packet's cellophane on the uppers (like a condom) when I slide the seals on (To prevent them from snagging on any metal.) Matter of fact, a condom might even work, but the material is probably too thin to protect anything...
The most important step to replacing fork seals is figuring out the cause of the seal failure. Age is common, and if there are no other factors, you just replace the seals. Dirt is also common. Most fork seals have dust covers (sold separately) to keep dirt out of the seals. If your old seals are dirty, you need new dust covers. You also must inspect the smooth fork uppers for chips from stones. If the metal is shipped, it will chew up a seal in no time. There are a few fixes, depending on the chip. Best, of course is to just get a replacement upper. You can also have someone fill the chip in and then grind it and sand it smooth, or you can just smooth the edges of the chip to prevent the seal snagging on a sharp edge. The second 2 "repairs" unless done professionally usually result in diminished seal life.
One last word. FORK GAITERS might be a wise addition to your bike. Not only do they look cool and "old school", the protect your forks from stone ships and keep your oil seals better protected from dirt than simple dust covers.
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what was getting quote for in the ~80$ range was basically 2 of these Rebuild kits
My left one is leaking, along with a funky dust shield. right one is still fine, but since i have no idea the oil weight or condition of the internals, i figured i would go ahead and do both forks, put in some heavier oil, and Maybe.....
That $1 mod is an old trick, you can use PVC pipe or anything of the proper diameter as a spacer. Shouldn't have any problems w/ it.
If you are going heavier weight oil than stock, make sure you put no more than the proper amount in. Screwing too much w/ the oil (Like adding too much) can blow seals as well.
“People demand freedom of speech as a compensation for the freedom of thought which they seldom use.”
- Soren Kierkegaard (19th century Danish philosopher)
TechTMW: Thanks for moving this to the right place. I was wondering where this should go.
Also, when filling with oil is there a good "tool" to use to get the proper amount of oil in there? Oh and where do you get the dust caps. That's the main reason for my failing. They are cracked and broken.
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"Fighting for peace is like screwing for virginity."
“When you step on the brakes your life is in your foot's hands”
-George Carlin
my old XS needed fork selas...the garage wanted to charge me 300 bucks to change them.... i told them to do two obcene acts upon themselves, one preceeding directly from the other.
Dust caps should still be available from yamaha. If you want Gaiters, you could probably pick some up for a dirtbike w/ the same size tubes.
I use a syringe w/ cc graduations on it to measure my fork oil, but for your bike (Different filler setup) you could probably just get a Ratio-Rite type of pitcher (For mixing 2-stroke oil) and use that.
“People demand freedom of speech as a compensation for the freedom of thought which they seldom use.”
- Soren Kierkegaard (19th century Danish philosopher)