Looking for a little advice on changing fork seals

[Anonymous]

I have an '82 GS1100L with blown fork seals. I have new seals and dust covers in hand. The Clymer Manual that came with the bike only covers GS1000 up to '80 so I'm seeing a few differences. I'm looking for one that covers mine.

1) There is some light pitting / rust spots on the forks, I read a thread that advised a little wet/dry (sand paper?) to clean these up. Can somebody expand on what grit is preferred. Is there a technique? I assume thorough cleanup is in order after a step like this.
2) How much oil and what weight should go into each leg?
3) Is it normally necessary to complete remove each leg or can the seals be replaced just be removing the lowers (seems getting enough ground clearance to get the lowers off might be an issue??).
4) There is an air cap at the top of the left fork and chromed bolt/cap over the right one. Shouldn't there be an air cap for each leg? How much air goes in (I've read here how a sensitive gauge is in order)?

Sorry for so many questions.
Chris

 

[Anonymous]

Hey guys - it would also be helpful if someone could relay the correct fork oil level too - (I read the in the archive about using the a straw to get the level perfect).

Thanks
Chris
'82 GS1100L

 

[Anonymous]

Chris:

I thoroughly overhauled the forks on my 1983 GS750ES recently. While I can't comment on model-specific items, here are some general comments:

1) You can use wet/dry soaked in oil for cleaning up imperfections in the fork chrome if they are not too bad. Start with #320, then #600, and finally #1200. Be prepared to spend a lot of time and effort......chrome is very hard, which is why they used it. However, something caused your seals to fail, so it is worth the effort in removing the cause (unless just plain old seals).

2) I recommend completely removing the fork legs so that you can strip them down, inspect and clean them. The manual recommends replacing the inner (lower) anti-friction bushings as standard. Mine were OK as they had been replaced 13,000 miles ago at the previous seal change. However, the outer (upper) bushings were very worn since change is not specified, so they were still probably the original items. Be careful with the bushings if you intend to reuse them (the bushing surface is teflon coated). I replaced both sets on each fork leg. I also thoroughly cleaned all parts with kerosene. Be careful with the valve spring and valve......they are just flimsy, thin, spring steel washers. Make sure that you reassemble them in the right order (my dealer hadn't during the previous seal change).

3) You can use a straw or a rubber bulb (e.g. for battery maintenance) attached to clear plastic tubing to measure fork oil height (and adjustment, if necessary)

4) One of the usual hard bits is removal of the damper rod. You can use various devices to stop the rod spinning in the leg while undoing the external allen bolt at the fork's lower end. Inverted 5/8" spark plug sockets, broomsticks, etc. have been used. Do a search in the Forum for suggestions......I know that JayB, amongst others, has made posts on this subject.

5) Make sure that the front end of the bike is securely supported before removing the forks. It may have to sit "forkless" for a while.

6) There may not be an air cap on each leg if they are linked, as on my bike........someone else will have to advise you on that and the fork oil weight.

7) I may have made the task sound daunting but it's really not too complicated if you are prepared and take your time. If you do it right by cleaning up the internals, smoothing out pits in the chrome, etc. and replacing worn parts, you may never have to do it again!

Good luck,

Simon

 

[Anonymous]

GS1100 forks

GS1100 forks

. I'm not exactly an expert on fork rebuilds(i've only had to do 3 pairs ever), but I hope I can help a little. I took my 750EX's off so i could do them in a vise, clamping them down at the caliper mount. At the time,I wasn't near my toolbox(it's where I work) so I couldn't get the damper rods inside the forks loose so I couldn't seperate the 2 halves of the forks. I cheated and used a small pin punch to pop 2 holes opposite each other in the seal(after removing the snap ring of course).Then I screwed 2 thin but long wood screws into the holes and yanked them out with pliers.If you do it this way be CAREFUL not to drive the heck out of them(seals) when you punch through so you don't nick the inside of the lower leg. I used a piece of aluminum pipe to use as a driver to reinstall the seals. As for oil, I use 15w Bel Ray fork oil at just over 6 1/2 oz. of oil and 15psi of air. I have a factory manual and the oil levels range from 6.4 oz(191ml) up to 8.3 oz.(237ml). Maybe drain one fork into a measuring cup and see how much you roughly have(unless of course they slobber so bad they're half empty, so this won't work very well).
AS for the pitting, Simon's on the money with that one. Use anything coarse and you'll change seals often because of the scratches it will leave.Oh, one fork air valve usually means they're linked together someway.The one I'm used to is tied together through a line at the lower fork clamp. Unfortunately, my 750 has individual valves on each leg and they're a pain sometimes to balance spot-on. Teed in is definitely better.
DEpending on how you like your ride, 15w should be ok for you for oil.Last tip , air your forks with the front end off the ground to get it accurate. And watch with unregulated shop air. The high pressure could blow a brand new set of seals(DONE IT ONCE MYSELF).I do it with a bicycle hand pump now;paranoid I guess.
Good luck to you!!!!!
Jon
p.s., Suzuki says max. pressure should not exceed 35psi and they consider 7-8 psi standard pressure.I like it a little stiffer than 8psi, but thats just me.