changing fork seals

[gearhead13]

So, my fork seals are leaking, there was a puddle under the bike after it sat overnight.
Is it possible to change the seals with out disasembling them?
My manual just shows how to take them apart. I have never taken forks apart before and I would rather not start now.

 

[Guest]

ive never done them before but i do believe you have to.

 

[TheCafeKid]

So, my fork seals are leaking, there was a puddle under the bike after it sat overnight.
Is it possible to change the seals with out disasembling them?
My manual just shows how to take them apart. I have never taken forks apart before and I would rather not start now.

Its NOT hard at all. In your case, Yes, you do have to completely disassemble them to remove the seal and replace it. I just did 2 sets, one just like yours, and one of the more modern forks in the GS line. YOURS are cake, the others....not so much, but still not horribly tough.

 

[gearhead13]

Ok, thanks for clarifying that. The manual shows a hex allen at the bottom and a bolt? inside that you have to turn. How far down is it to the inside bolt (or allen)? Can I use several 3/8" extensions to reach it? Anyone know what size it is? Should I replace the "anti friction guide thingys" as well?

 

[salty_monk]

19mm from memory. You need the reverse end of a Craftsman plug socket on some extensions or some all thread with the right size nut locked onto it at each end (one for the fork one for your wrench). Some just jam it up with a broom handle down the fork but I've never tried that.

If you have air forks you can actually release the clip & pump in so much air the seal pops out - did both my 1000's this way. needed about 170psi (put in with a bicycle track pump by hand in my case).

The bush you're talking about is not normally worn out.. if you have no play in the forks then it's unlikely you need a new one.

Dan

 

[emjay]

19mm from memory...

Correct, 19mm.

Some just jam it up with a broom handle down the fork but I've never tried that ...

The broom handle trick works, but best if it's hard wood. Someone I know welded a 19 mm hex nut onto an extension.

 

[bonanzadave]

Yes, you do have to completely disassemble them to remove the seal and replace it.

Cant you just slide the forks down out of the tree. Pry out the old seals and then slip in a new ones.

 

[TheCafeKid]

Isuppose you COULD do that, but trying to pry that seal out without messing up the upper fork tube will be a little tricky. They're in there pretty good, as Dan pointed out it took 170PSI to push it out (the MAX amount of air that should ever be in a fork in use is 35PSI, so you see there) I had to use a seal puller on mine but mainly because i was worried about Fing up the fork lower. The 550 ones i did you just sort of use the fork as its own slide hammer and popped em out, but the ones this gent is working on dont work like that i dont think.

 

[Guest]

... the reverse end of a Craftsman spark plug socket on some extensions...

+1 on the "reverse" spark-plug-socket-on-an-extension trick. Worked like a charm on my 850GLZ front forks.

Another tip I learned here - keep the old seals & put them on top of the new ones while you press them in place; it will keep the new seals from getting buggered.

good luck,

mike

 

[bonanzadave]

trying to pry that seal out without messing up the upper fork tube will be a little tricky.

So R U telling me thats why I got one that leaks......

Im gonna put some air in the fork and squirt some soapy water on the seal to see if I can tell if its leaking on the inside or the outside.....:-k

 

[Steve]

19mm from memory. You need the reverse end of a Craftsman plug socket on some extensions or some all thread with the right size nut locked onto it at each end (one for the fork one for your wrench). Some just jam it up with a broom handle down the fork but I've never tried that.

I have not done the reversed plug socket, it looks like it might work.
I have done the broom handle bit, but only succeeded in splitting the end of the broom handle and putting splinters in the fork tubes.

What worked best for me was the all-thread rod and jammed nuts.
5/8" rod, 2 feet long, works very well. Here is what it looks like when done:

Leave some rod sticking out at one end, it helps center the tool in the piece you are trying to remove:

.

 

[Glen]

I just replaced the seals on my '82 1100E, it really wasn't hard at all. I used the tool that Steve has picture of in the above post. In my case, I used 1/2" threaded rod. The 1/2" (inner diameter) nuts were pretty much a perfect 19mm on the outer diameter. Here's what I did:

-Remove wheel, fender, and calipers
-Loosen the fork caps, for me it was 22mm
-Loosen bolts on triple-clamps and pull forks out by twisting
-Remove fork caps and springs
-Hold upside-down and drain oil
-Put lower leg in vise (use the caliper mounts)
-remove allen key from bottom of fork - 8mm, this is where you use the tool
-remove the dust cap, circlip, and washer from above the seal
-grab inner leg with both hands and yank a few times until the entire fork comes apart
-I've read in the manual (and on here) that the seal should go in next, before the inner leg, but I didn't do that. I actually reassembled the fork, then inserted the seal right over the inner leg. I used a piece of PVC pipe to drive the seal.
-Fill with oil

That was pretty much it. I also cleaned everything with mineral spirts.

 

[bonanzadave]

That was pretty much it.

What did U do about the brake lines ?

 

[Hammered]

My GS750 was so easy, even I could do it. And I guess I got lucky. No special tools were needed. The Allen head bolts in the axle saddle area broke free nice and easy with the help of my impact screwdriver. The service manual wasnt really needed but was nice for reference purposes. The measuring bottle in the pic came from a beauty supply store here local. It was marked in mL, so that made adding oil easier.

 

[Steve]

I used the tool that Steve has picture of in the above post. In my case, I used 1/2" threaded rod. The 1/2" (inner diameter) nuts were pretty much a perfect 19mm on the outer diameter.

Yeah, 1/2" it is, for Zooks. I forgot that my tool, with the 5/8" rod was what we used for my son's Venture Royale.

I also used a piece of PVC pipe to drive the new seals in. I think it was 1 1/2" pipe. It almost just barely fits over the 35mm fork tubes, so I cut a slit along the entire length so it could expand a bit. If the PVC pipe is longer than the upper fork tube (only takes about an 18" piece) and the end is cut square, you will have absolutely no problem driving the seals into place squarely, with no chance of damaging the upper tubes.

.

 

[Glen]

What did U do about the brake lines ?

huh? I just unbolted the calipers from the forks, then used a wire to suspend the calipers, if that's what you mean.

 

[Guest]

C'mon guy! If you can rebuild a motor this is a walk in the park.

 

[gearhead13]

C'mon guy! If you can rebuild a motor this is a walk in the park.

Ya, Ya , but engines are cool and interesting, forks are boring and tedious

 

[TheCafeKid]

What did U do about the brake lines ?

I left the calipers attached to the brake lines, then set the calipers on a chair or box or something as not to stress that rubber. If you have stainless lines, You could just leave them hang...not gonna hurt anything for the ammount of time they'll be there.

 

[jwhelan65]

I cannot remove the top fork tube seats on mine ( rusted closed ) Can they be filled from the bottom?