DIY fork seals

Now that the long awaited gpx is almost a complete bike the fun is starting to go out of the whole DIY thing. One of the first things I changed (3 months ago now) was the forks, so since then it has sat quietly seeping oil down its legs. Should I attempt this job myself, or is it time to *deep breath* pay someone to do it for me? I have a reasonably well equipped workshop, but no SST's.

Doesnt cost much to get a workshop to do it and saves a bit of swearing, of course you dont learn a lot sending the bike to a workshop.

Oh, believe me, I've learnt a lot already. I'm just trying to find out if I've learnt when to give up.

I've done almost everything on this bike myself. The only time I've been near the bike shop has been to buy parts. I would really like to be able to say I did it all myself, but this last job looks messy. I don't suppose there's any way of doing them without pulling the forks apart?

The most difficult part is to losen the underside screw. Need either an airgun or a special tool (long square pipe). When I got to this stage the last time I had to take it to Brigton kawasaki in defeat

Yeah you have to get the tubes rattled apart, other than that it is all pretty straight forward.

you dont actually have to take the fork tubes out

it is possibly to get the seal out without taking the tube out, it just is harder and you must be careful not to ding the chrome or the new ones will leak

use the old seal to drive the new one in

overall not a real hard job,

you dont actually have to take the fork tubes out

it is possibly to get the seal out without taking the tube out, it just is harder and you must be careful not to ding the chrome or the new ones will leak

use the old seal to drive the new one in

overall not a real hard job,

Dead right - you will generally have a circlip of some type that sits above the fork seals. Remove it - you will need a small pointy instrument (very small flat-blade screwdriver, etc).

Once it has been removed, then you just need to dig out the old seal, being careful as Johnnie5 has said, once you dig a screwdriver into the old seal and work it around, the old seal will gradually move up and out of its seating position - you can then slip it straight off the forks.

You can use the old seal to help seat the new one (as long as it is not too traumatised from the removal....) - I generally use a piece of PVC tubing that slips over the fork-leg. The new seal will seat pretty easily.

Its a much easier way of replacing fork-seals than splitting the forks

I witnessed this being done to a race bike in between races a while back. They slipped the forks out, removed the dust seals and circlips, then made sure the forks were fully extended with full preload. then wrap ductape around the top lip of the seal seated on the chrome fork leg. Remove all preload. Now this next bit freaked me out. squash the fork leg, then extend it slowly as you watch the fork seal rise. The ductape slips under it as you compress it quickly, then the slow friction makes it bite on the extension and lift the seal. Pretty neat trick I thought for an emergency fix.

However usually, apart from worn or perished seals, the fork legs usually are in need of a light linish to ensure the new seals bed properly and you don't just end up with new leaking fork seals! So pulling them apart is a better Idea. If you pull the legs out, and are friendly enough with a local shop, they will normally loosen the bottom bolt for ya. Especially if you bought all the parts from them.

I witnessed this being done to a race bike in between races a while back. They slipped the forks out, removed the dust seals and circlips, then made sure the forks were fully extended with full preload. then wrap ductape around the top lip of the seal seated on the chrome fork leg. Remove all preload. Now this next bit freaked me out. squash the fork leg, then extend it slowly as you watch the fork seal rise. The ductape slips under it as you compress it quickly, then the slow friction makes it bite on the extension and lift the seal. Pretty neat trick I thought for an emergency fix.

However usually, apart from worn or perished seals, the fork legs usually are in need of a light linish to ensure the new seals bed properly and you don't just end up with new leaking fork seals! So pulling them apart is a better Idea. If you pull the legs out, and are friendly enough with a local shop, they will normally loosen the bottom bolt for ya. Especially if you bought all the parts from them.

sounds like a good technique which would work well with nice and soft seals but going back to an almost 20 year old GPX those seals are going to be as hard as a groom on his wedding night

strikas method of visiting the shop you bought the seals from would work well , as it will take them all of 2 mins to pop the bolt out of the bottom of the fork and makes it a whil lot easier to get the seals out without dinging the chrome

Thanks guys. I've had a bit of a go at the old set. No way is that bottom bolt coming undone. I've tried screwdrivering the seal and thats not budging either. Don't think I'd be game to try it on the good ones. Anyway, the head mechanic is going into the shop on Monday to pick up my brake discs n stuff, so he will see how much it'll cost to have them done 'professionally'.

Yeah i think thats a good move daisy.You can get the old seals out as mentioned above,but you could stuff the new seals not putting them in squarly or even worse,mark the tubes whilst doing it which will mean your new seals will leak also and you have waisted time and money.
The proper way to do them is to pull them apart,then the legs can be checked for marks and also the internals of the forks can be washed out properly ready for the new oil.
If you are gunna do a job,do it properly otherwise you might find you end up doing the same job twice.

I'm pretty sure I could put new seals in, I've done them in my car. The problem is getting the thing apart without doing any damage.

Well I had some help. The head mechanic took them to work - with strict instructions that he was to ONLY loosen the bolt. I pulled them apart and did the seals myself. I'll try not to break my arm patting myself on the back.

Well done ! Its always a good feeling to have done this yourself.

Did you take the forks back to old mate mechanic so he could tighten up the lower fork bolt ?

He says they're too small to use the rattle gun on, but he's going to bring it home tomorrow anyway. Apparently they weren't very tight - unlike the original set that I was practicing on.