Help identifying damper

[jonesey]

I just acquired a "super fatty" headshok from (I believe) a 2005 F400. After inspecting it the good news is that the action of the fork is the smoothest I've ever experienced, and looking under the boot it's absolutely clean. Not a hint of corrosion, just some nice grease.

The bad news is that the lockout doesn't work, and it loses air pressure. I'm not sure what damper this is so I thought I'd post some pictures and hopefully someone can let me know. I would like to get replacement seals to see if I can get it operational again, but not sure if such things are available these days.

 

[Nico]

If the lock out is not working that probably means the oil has leaked out over the years so it needs a refill.
Or the lock ring inside the damper is broken.

For as far as I know there are no service kist for the dampers.

So for the seals you have to look online.
The seal that shows in the last picture is called a quadseal.
If you use that as a search term you will find companies were you can order those.
Quad seals come in a limited variety so it will probably easy to find the correct seal.

 

[black lightning 1987]

Check with Craig at Mendon Cyclesmith.

 

[jonesey]

I'm not too worried about the damper not locking out, but I'd like it to keep air at least.
Thanks for letting me know the name of that type of seal. I'm pretty sure that's the culprit. It seems quite hard and one of the ridges is smaller than the other. I've tried giving it a good coating of suspension grease, but it's still got a slow leak. I'll see if I can find one, and if not it'll be off to Mendon Cyclesmith as I think this fork is a keeper

 

[JohnnyD]

I'm not too worried about the damper not locking out, but I'd like it to keep air at least.
Thanks for letting me know the name of that type of seal. I'm pretty sure that's the culprit. It seems quite hard and one of the ridges is smaller than the other. I've tried giving it a good coating of suspension grease, but it's still got a slow leak. I'll see if I can find one, and if not it'll be off to Mendon Cyclesmith as I think this fork is a keeper

I have a Headshok DL 80 off my F600 Furio that will soon be headed to Craig for some TLC. Worth the price IMHO to keep it going and on the bike.

 

[jonesey]

I think I have got it working!
Thanks to @Nico for letting me know the name of the seal. After much careful measuring I determined that the seal I needed was a 210 Quad seal (3/4'' ID X 1'' OD X 1/8'' Cross Section). I installed it, applied grease, and it did hold air overnight. Longer term testing will tell me more, but it looks like it's working.

I also filled and bled the damper. It doesn't fully lock out now, but it's much better. Now there is some damping with basically a normal and firm mode.