2009 Fork Seal Replacement - Help!

[MattF760]

I've been having trouble getting my forks apart to fix leaky seals...

I have the 2004+ model forks and I also have the special tool, but the tool will not piston from turning when I try to remove the bottom bolt. The tool meets a smooth, circular portion before anything else. It doesn't look like a hex pattern. I've watched BaltimoreGS's fork seal video, but he uses the older fork model. On the diagram below, it shows that the piston should have the same pattern as the special tool or maybe a 12 point (top of #13), but it's completely circular. I've tried setting the fork on top of the tool and standing on the T handle and I've locked it into a vise, but I can't seem to stop it from rotating. Could that circular piece be the oil lock (#12)?


I've searched the forum and I can't seem to find any answers... Just people saying these things are hard to take apart. I just want to know if I'm doing it right, if I have the wrong tool, or whatever else I'm doing wrong...

Thanks in advance!

[lucas]

Some folks on here have had success with jamming a wooden dowel or broom handle into that piston. 

I believe in that video he uses 5/8 inch nuts.  What size nuts you using?

Even the newer forks should have a pattern in the top of the piston that mates with the special tool.  Is it possible that the fork seat or some other parts are down there preventing you from reaching the piston?

Would you try taking a photo of the view down your forks?


P.S. the 5/8 refers to the diameter of the threaded part, the outside of a 5/8 nut is 15/16

[MattF760]

This is the piece I was talking about. It does not move when I rotate, compress, or pull on the inner barrel, but it does rotate when I try to unscrew the bottom bolt (#16 in the diagram above). Totally circular, no pattern. Not able to be gripped, even by the tool. Maybe I got a defective tool? The grooves aren't very sharp/deep.

Maybe you're right, a broom might work... The rotation of the entire piston is the biggest problem.

[Bluesmudge]

I have heard that the special tool does not work and you need to shape a broom handle and jam it in there. Maybe some of the forks actually have grooves but I think most are just smooth. Terrible design.

I'm going to try this myself in the next couple days. I'll report back if the broom handle works.

[Bluesmudge]

Ok, I went ahead and started my own fork seal replacement and I confirm that :

1.) The damper rod is an SOB to get out on the newer forks.

2.) The broom handle trick does work if you fuss with it long enough.

When I ran into trouble, I used this post by Slack as a guide: http://gstwins.com/gsboard/index.php?topic=59261.0
Its mostly about cartridge emulators, but requires the same process of removing the damper rod.

I purchased a tapered-end broom handle from Home Depot for $7. Its not even close to the correct shape. It takes a bit of trial and error to get it sized so that its small enough to fit when you pound it in there with a hammer, but not so small that it doesn't provide friction. I carved it to perfection with a box knife.

I made a bunch of vertical cuts with the same box knife to rough it up and increase the total surface area grabbing the rod. I also sprayed the inside of the fork and the broom handle tip with parts cleaner to provide oil free contact. After about 30 tries on each fork I got them apart. I think an impact wrench would have negated the need for such a perfect broom handle shape and would have been a good investment for the project.

[MattF760]

Yeah, I used similar ideas.

I did shoot parts cleaner into the fork to eliminate any lubrication.

I also tried the wooden dowel/broom handle technique: I shaped a poplar dowel into a cone using a box cutter and a dremel, hammered it into the piston head with a rubber mallet, held the wooden dowel in place with a vise, and tried using an impact driver (the manual, hammer type) on the bolt on the bottom. It wasn't rotating for a while, but I couldn't loosen the bolt at all. Then I tried a ratchet but it started rotating.

I think that your vertical line trick is a fantastic idea, I'm going to try that next. I ended up taking the forks on my bike to a local shop because I just needed it done, but I do have two other sets that I would like to work on. If I figure anything else out, I will post it here in hopes that others may learn from my mistakes... 

Thanks, Bluesmudge and lucas!

[MattF760]

Talked to the guy at the shop. He says they leave in the spring, the washer, and the tube, compress it against the wall and then use an impact gun to get the bolt loose.

[Bluesmudge]

That makes sense actually. What method did the shop use to compress the fork against a wall?

On one fork I tried to loosen the bolt while the fork was still fully assembled, but the weight was already off the front wheel and it did not work. I wonder if it would come loose with an impact wrench if the springs were preloaded with the weight of the bike or the bike + a rider.

[MattF760]

The tech didn't go into detail, but he said that he uses brute force and compresses it with the impact wrench. Maybe they use one guy to hold and compress the fork while the other guy mans the impact wrench, that way they don't put wear on the gun. Not too sure.

That's a good idea, but I imagine that it's pretty difficult to get to the bolt on the underside, not to mention the metal bushing that goes through the right fork on the bottom.

[RichDesmond]

An impact wrench helps a lot. If you don't have an air compressor Harbor Freight sells an electric one for $60-$70 dollars that works well