315r Fork Seals

[patmustard]

I changed the fork seals on my 98 315r (Paoli forks) last weekend but they started leaking again almost straight away. I can't see any scratches or damage to the stanchions, I put 360ml of 5w oil in each leg and the seals were fitted the same way round as the old ones with the spring part facing up. Is this right or were the old seals in the wrong way as they didnt look too worn out? Failing that is there any other reason why they may leak even with new seals.

Thanks in advance.

[wherry]

Have you just changed the dust caps, with the spring exposed, at the top of the lower fork leg? Not too clear from your post.

If so the oil seals are further down under the wire clip.

If not apologies. The seals should be with the inner spring reinforcement facing downwards. Wire clip on top to hold them in place. It's important to make sure that they are in straight.

[patmustard]

Thanks for the quick response Wherry, I changed the oil seals under the wire clip, the dust covers looked ok so I re used them. I'm pretty sure I put the new fork seals in with spring reinforcement facing upwards as this was how the old one's were, could that be the problem?

[tt5th]

Yep, sounds like it.

[wherry]

I'm pretty sure I put the new fork seals in with spring reinforcement facing upwards as this was how the old one's were, could that be the problem?

Almost certainly. There's also something on here somewhere about there being a difference between seals. We need ones here designed for hydraulic applications obviously, not for spinning shafts. If you've bought honda/montesa ones you should be fine. I've got some random seals from a bearing factor that let a tiny bit of oil through, particularly when the temperature rises, and I've wondered whether they are the right ones or not. Next time I renew them I'll make some more enquiries.

[patmustard]

Thanks for that, I'll check which way round they are when I get chance and report back. Thinking about it though it does make sense as if the open spring side was facing downwards the oil pressure would tighten the seal?

Note to self: when a manual says "installation is the reverse of removal" or similar this only applies if it was put together right in the first place.

[cherrybear]

The springs should be on the oil side. As you have worked out the hydraulic pressure of the oil will make the seals tighter.

[patmustard]

All sorted now, the seals were in upside down. Swapped them over and no leaks at all now, Thanks again for all the sound advice.

[wherry]