Installing progressive springs, and replacing seals

[Scott_DC]

So a few days ago I noticed that my left fork on my 1994 GS500 is leaking oil. Doh!

After some quick searching on here, it sounds like i need to replace the seal in the fork. And heck - while i'm in there (since it looks like you have to completely tear the whole thing apart to replace the seal) might as well take out the stock springs, and replace them with the progressive springs.

I want to make sure I've got everything before i start this (hoping to do it this weekend), since the bike is my only transportation and it'll be hard to go get stuff in the middle of doing work on it.

So here's what i think i need

• Set of progressive springs (on their way from chaparrel)
  
• 2 new fork oil seals
  
• 15w fork oil (how much?)
  
• 2 new spacers
  
• kerry's funky tool for removing the spinning bolt.
  [/list:u]
  Is that all? I'm assuming i should replace the seals on both if they went on one. Do i need to worry about the bushings? any other parts i should count on replacing while i'm in there?
  
  Thanks,
  Scott

[tt_four]

i don't think you'd need to replace both, but they only cost like $12, so you might as well, i think the tool you're talking about is the two long bolts stuck together in the middle, that makes things so much easier,

the only other thing i saw on your list that you didn't have, is the plastic pvc pipe you need to jam the fork seal down into the fork, do a search for old posts about for seals to see exactly what size, i think inch and a half, but i can't say for sure, you're in the same situation as me though, my bike is my only trasnportation, and the hardware store only sold 10 foot sections of pipe for $4, so i was out in the parking lot with a hacksaw, but i bet there's a smaller peice that would work, there's all kinda random parts made for plastic pipes, just go in the hardware store with the fork seal, and find a peice that is the same size as the fork seal and use that to jam it down, for the spacers, from the same section of the hardware store, i just used plastic caps for half inch pvc pipe, like $25 each, and as far as the fork oil, they sell it by the liter, like $10 for the 15w, and one liter is more than enough, so just one bottle will fill up both

[cozy]

If you're gonna do all that , you will get the best gain in ride from swapping out the rear shock with a Katana shockwhile you're at it.  There's tons of threads about them here if you do a quick search.  

[Kerry]

Here's what Richard and I used for seating the new seals.  (Just like what tt_four described.)



It may have been longer than we needed (I can't remember), but it stores away nicely with the "bolt turning tool".

EDIT: Changed link from sisna.com to bbburma.net

[raindrift]

You'll also need a ruler that measures in millimeters, and something that you can dip into the fork tube to check the oil level.  I used a piece of brazing rod, bent into a "T" shape so that I couldn't accidentally drop it in there.  I just marked it at 140mm by scoring it with a pair of wire cutters.  Worked great.

It also helps to have some sort of little measuring cup with a spout on it for pouring in the fork oil in small increments.  It's hard to be really precise when pouring from the bottle.

Oh, and I heard someplace that if you put a few drops of fork oil under the dust caps, on top of the fork seals, it'll help keep the seals from drying out.  Seems like a good idea, and it can't hurt.  Of course, you'll have a little oil on your fork tubes after that -- don't worry, it's not leaking.  

I made a double-bolt tool, but Home Depot's bolts were labeled wrong, so it ended up not fitting.  In the end, I just put the new springs in the forks (they're quite a bit stiffer), put the caps back on, hooked a ratchet tie-town strap (a comealong) onto them and ratcheted them all the way down.  Then I turned the allen bolt at the bottom of the slider until it came loose.  It sounded like things were spinning around in there for quite a while before it finally came undone...  I think it needed to twist the spring a little to get enough tension on the bolt.

[Eightmarky]

I didn't change the fork oil when I installed my progressives and the front end feels great.  I also cut the new spacers from one of the old ones, so you don't need to buy those. :mrgreen:

[AR5ENAL]

Akh, I'm doing this same swap as soon as my fork seals arrive from ronayers.com.

My fork seals aren't leaking at all, but i figured it would be easier to replace them now, instead of later on down the line...

A question I had is, how did you guys make sure your forks were at the same height when reinstalling?  The Hayne's manual says to check the top yoke for how the fork aligns, but there has to be a better way.  I was thinking of masking off the forks right below the pinch bolts, and then realigning them there when i put everything back together.  Any ideas?

[raindrift]

I just installed them so the top of the fork tubes were flush with the top of the yoke (that is, the piece above the upper clamp and pinch bolt).  I think it was probably accurate enough to just feel the edge of the cap with my thumb, and make them match as closely as possible.

It seems to work fine, anyway.  I don't think you'd be able to get it any more accurate by marking with tape.

[Kerry]

Ditto.

[jake42]

kerry,
my search is not working today for some reason. can you send the link to the post about how to build the bolt tool for separating the sliders.

jake

[The Antibody]

To take the cap off of the top, you do not need a special tool. Just use a large ratchet with out any sockets. It will fit right in.

 -Anti

[raindrift]

The funny tool isn't for removing the cap from the fork tube, it's for unscrewing the damper rod from the bottom of the fork slider.  If you don't have a tool to hold the damper rod in place, it just spins around when you try to remove the bolt at the bottom.

You can kinda hold it in place with spring pressure (worked for me, but doesn't for everyone, and it's a pain in the ass).

[Kerry]

can you send the link to the post about how to build the bolt tool for separating the sliders.

See the thread Bad Day Wrenching on the GS

[Scott_DC]

Thanks for all the good advice. I'm picking up the fork oil and oil seals from the dealer tomorrow, and i'll be up at the crack of dawn working on this on saturday. Definately looking forward to improved handling over the poorly maintained streets of DC.

[Scott_DC]

So i replaced my seals, installed the progressive springs, and put 15w fork oil in on saturday. Took me about 3 hours (i think. Wasn't paying much attention to time). Couple of observations:

1) Kerry's tool worked great. Picked up 2 5/8 x 8" hex bolts, and one 5/8" nut. Put on the 5 minute epoxy, and screwed the bolts into the nut and the tool worked great!
2) The oil that came out of the forks was nasty. Came out a nasty black color. The new oil was a light green. And - here's the kicker - the side that was leaking.... the oil was lighter in color. I'm assuming the previous owner (who had mentioned something about changing the fork oil 800 miles ago) knew the seal was leaking - and added more oil/changed the oil. Call me a cynic - but i think he was hiding that defect.

but the positive is

3) The bike handles _much_ better now. The streets in DC are cruddy at best, and in riding around yesterday, and in my commute today through Georgetown (Which always is torn up these days), the bumps were much more manageable.

Thanks to everybody for their help in this. I tell ya- i love this bike, and this forum

[Scott_DC]

Oh - almost forgot to mention. The brakes seem grabbier since i worked on the bike. Did i mess something up? Unknowingly fix something? Start hallucinating?

[Jeremichi]

I hope everything goes as smooth for me as it did for you.  I'm replacing my seals and boots tonight.  I used an impact to loosen the allen bolts.  Just have to remove the old seals and put in the new.  I'm just a bit concerned about the fork oil level.  Hopefully I get everything right.

[Kerry]

Question for those that have loosened the Allen bolts with an air or impact driver:

How did you get them tight again?  :dunno:

[Jeremichi]

Haven't gotten there yet :dunno: But I actually took one of them off with a pipe and an allen wrench because the driver wasn't long enough.  I just had my friend compress the spring while I loosened and was hoping I could tighten it that way too.

[AR5ENAL]

I'm still waiting on my seals to come in (hopefully this week), so i'll be attempting this on saturday most likely.  I'll let you know if my front brake ends up grabbier.  

My guess is that because the front doesn't dive as much as before, the energy is spent slowing the bike down, instead of compressing the front suspension.  This is total hearsay though...anyone know what's really happening?