question on changing fork seals.

[gord_s]

Hi, I'm just changing the seals on an 83 550e, I've got one fork out, do I need to disassemble them to remove the seal or will the old seal pry up and slide up the tube. I've got the snap ring and washer out so the old seal is right there but doesn't want to pry up and out, I'm trying to be gentle to not scratch the tube, though I better stop and find out if I'm just being to nice to it or do I have to split the forks to get it out. Thanks

[Steve]

I have seen some reports where a hole was drilled and a sheet metal screw or drywall screw was installed then pried against to pull the seal.

Personally, I would rather not take the chance of nicking the fork tube by doing that. You are better off taking them completely apart. That also gives you the chance to inspect the bushings to see if they need to be replaced, too.

The hardest part is separating the tubes. If you have an impact wrench, you're good to go. Otherwise, you will have to fashion what amounts to a very long allen wrench. Not sure what size your forks will need, but my wife's 850 required a 19mm. Fortunately, this is very close to 3/4". I used some 1/2" all-thread rod that was 2 feet long and installed 4 nuts, 2 on each end. The nuts use a 3/4" wrench, so it's just right. I left just a bit of the all-thread sticking out to help center the tool in the socket in the bottom of the fork tube. To help you visualize what you are trying to remove, picture the spark plug wrench that is in your bike's stock tool kit. You will be trying to install this tool you are making into the spark plug end of the wrench, but it will be at the bottom of the fork tube. When you get the tool made, clamp your fork tube to prevent rotation, inert an allen wrench into the bolt in the bottom of the fork tube (outside), stick your new tool inside, then use the inner nut to turn it out.

Here are a couple pictures of the tool that I made.





.

[tkent02]

There is usually a lot of crud, goo, bug parts, rusty chunks, and some other nasty but unidentifiable stuff in there. Take the few minutes it takes to get in there and clean it out.

[p_s]

What Steve said, but you can also you a spark plug socket. Invert it, connect it to a very long extension & a ratchet. I think it was the socket for 14 mm spark plugs.

Actually I don't remember which spark plug socket I used, but it was different on my '85 GS550ES than on other GSes, but one of the common spark plug sockets did fit.

[Steve]

but you can also you a spark plug socket. Invert it, connect it to a very long extension & a ratchet. I think it was the socket for 14 mm spark plugs.

I did not think of doing it that way.

I might have tried it, but I did not have enough extensions to reach all the way down. I think it's cheaper to get the all-thread and four nuts (about $5).
And ... you don't stand the chance of your string of extensions coming apart.

.

[BassCliff]

Hi Mr. gord_s,

This might help too. It's Mr. Matchless' "how to":

Fork Seal Replacement
(by Mr. Matchless)


I try to collect helpful bits on my website. Feel free to stop by and help yourself.

Thank you for your indulgence,

BassCliff

[Steve]

This might help too. It's Mr. Matchless' "how to":

Fork Seal Replacement
(by Mr. Matchless)

On page 6 of that paper, the top picture shows what your tool needs to hold.

Good write-up, Matchless.

.

[chef1366]

I removed my allen bolt with an impact with the spring installed and compressed with the fork cap. Comes right out.
If these are air forks fill them with air untill the seal pops out. (via Saltymonk) Only do this if there is NO WAY you can seperate the fork. I'd advise to seperate so to clean them up and get all the old fork oil and crud out.

[Gary Lich]

Hi, I'm just changing the seals on an 83 550e, I've got one fork out, do I need to disassemble them to remove the seal or will the old seal pry up and slide up the tube. I've got the snap ring and washer out so the old seal is right there but doesn't want to pry up and out, I'm trying to be gentle to not scratch the tube, though I better stop and find out if I'm just being to nice to it or do I have to split the forks to get it out. Thanks

Yes, taking the forks apart is the right way to do it , however, if you carefully drill a small hole in the top of the seal then put a hook on the end of a small rod just big enough to fit in the hole you can pop the seal out (I've done it several times and never damaged a tube) you can also use the the old seal on top of the old one to seat the new seal in place...

[gord_s]

thanks for help guys, looks like I'm taking my forks apart.

[82Shafty]

I used brake cleaner to clean out the garbage from my forks.

[rudy]

thanks for help guys, looks like I'm taking my forks apart.

You won't regret doing it. You'll really be surprised at the tar that comes out. I usually take the whole fork apart, then pry the seal out with my tire spoon. Lots of leverage, and the hooked end fits under the seal lip really well.

I've had it on my buddy's 77 750 where the seals didn't even come out with any amount of levering. Since I was going to polish the fork lowers anyway, I polished around the top where the seal is to heat up the tube. The seals popped out with no trouble at all after that. You could use a heat gun too to get the same effect.

[gord_s]

I was having thoughts of defeat today while at work thinking I would just take the forks into the dealer and have them take them apart and install the new seals I just bought from them. I'm just not feeling real confident about it since I've never taken a set apart before, I do want to do this though so I'll decide over the next couple days, I'll update. Thanks.

[lucabond]

I drained the fork oil then put 100 lbs of air in the tube and used a hot air gun to heat the seals. They just popped up after awhile. If you are going to do any digging with a screwdriver or a drywall screw do it with the tube full compressed so if you make any nicks they will be at the top of the travel and after you replace the old springs as you should the seals will never make it up that far. Good luck