Seca900 fork seals

Would something like Cold weld be appropriate?

 

Any 2 part epoxy that is meant for metal repair will do, so long as it's not the putty. Clean the nick so it is oil free, fill with a smear of epoxy, let the epoxy cure fully, then proceed to polish it as you would the rest of the fork.

 

I thought that I got everything out of the upper tube, but there is something left in there at the very bottom:



It looks and feels like a small collar held in lpace with a clip.

Does it have to come out or not?

 

NO!

 

I hear you loud and clear! I won't touch it.

Thanks Len!

 

ALl right, I spent a few hours sanding and polishing my upper tubes, lots of work but i'm satisfied with the results. Most of the marks and scratches are gone except for this one, which is in the seal travel section:



It is a fairly small scratch, less than 1/4" long, two hairs wide and two hairs deep, and it is at an angle in relation to the fork tube axis.

Should I fill it with coldweld or leave it as is? I wonder if it is deep enough to allow the epoxy to have a good grip...

 

I'd go ahead and epoxy it; it looks too deep to polish out. If you don't repair the gouge the fork seal will leak. The gouge is rough enough that the epoxy will grab it. It shouldn't fail before the next time you need to rebuild the forks, but it should be considered a temporary repair (it will fail eventually). Be sure to prep the surface with rubbing alcohol to remove all of the oil, or the epoxy will not bond to the fork leg.

 

Thanks k-moe, that's what i'll do.

 

I will soon get my new parts from Len so I'll soon be able to reassembly the forks.

I'd need some help though, because I can't remenber in which order I should put these three washers back , and which side of the bottom of the upper leg:



It seems to me that the two spring washers where inside the upper leg and the flat one outside, but it doesn't make a lot of sense, also it is possible the last one to work in there didn't put them back properly.

Edit: what you see on the picture is the damper rod with its allen bolt at the extreme left and then the aluminium-like sleeve that goes in the bottom end of the upper leg. The bolt has its own crush washer that you can't see on the picture.

 

The factory Yamaha service manual sez:

Assemble onto the protruding shaft of the damper rod in the following order:
- first on goes the flat washer (which Yamaha calls an "oil lock piece valve")
- then both wave washers (which Yamaha calls an "valve spring")
- then the aluminum sleeve (which Yamaha calls an "oil lock piece")

But wait, there's more!

The factory Yamaha parts diagram sez:

Assemble onto the protruding shaft of the damper rod in the following order:
- first on goes a wave washer (which Yamaha calls a "valve spring")
- then the flat washer (which Yamaha calls a "washer")
- then the other wave washer (which Yamaha calls a "valve spring")
- then the aluminum sleeve (which Yamaha calls a "taper spindle")


And finally, not to be left out, the Haynes workshop manual sez:

Assemble onto the protruding shaft of the damper rod in the following order:
- first on goes a wave washer (which Haynes calls a "wave washer")
- then the flat washer (which Haynes calls a "plain washer")
- then the other wave washer (which Haynes calls a "wave washer")
- then the aluminum sleeve (which Haynes calls a "damper rod seat")

Except for the parts descriptive wording, the Haynes manual and the Yamaha parts diagram agree in the order of the parts, and it seems to be that the logical sequence of assembly (i.e. there is no real point in having both wave washers nestled against each other).

 

EXCEPT:

The "step" on the bottom of the fork tube doesn't appear to provide a wide enough "flange" to properly press on/work against a wave washer.

Doing it the first way, with the plain washer, then the two wave washers, will simply double the springiness of the wave washer as opposed to having a single one there. But fitting a wave washer, then a plain washer, then the other wave washer will still only "double the springiness" but it also makes the stack taller.

I'm betting Haynes went by the fiche, which isn't the most accurate document in the world.

If it were me, and the fork came apart with the two wave washers together, trapped between the plain washer and the damper rod seat, then I'd follow what the service manual says and do it that way. You're probably the first person to have the forks apart.

 

The reason I think I'm not the first one to dig in there is because one of the fork is missing its damper rod bolt crush washer.

Also, if I remember correctly, the flat washer wasn't on the right side of the spring washers, according to what the service manual says.

Anyhow, I have what looks like a service manual, (I doN't have the cover), so I'l go with that. I felt better asking, because the manual osn't super clear about the righ tlocation of the taper spindle:



The manual drawings and pictures suggest that it should be installed INSIDE the upper leg, in fact IM pretty sure it was OUTSIDE (when I pulled it apart), at the bottom of the upper leg, like in my picture. Please tell me if I'm wrong...

 

I'd go by the factory service manual. On my 750 the order of the washers (from the top of the rod) was: flat washer, wave washer (just one), oil lock.

 

http://www.britbike.com/forums/ubbthrea ... ber=150782

Oh and a quick wave over with a flame is the best way to remove fork oil from the tube.

 

Two questions before I go any further:

1-I will keep the regular fork springs so do I simply put in 286 ml per fork or do I have to measure an accurate distance from the top of the fork to make sure I put the right amount?

2-what do you guys use to drive the new oil seals in place?

Thanks in advance

 

Replace the Springs with New Progressive brand.

Measure the Oil.

Cut a slot in a 3-Inch length of PCV Pipe.
Use a Hose Clamp to close the PVC Pipe to fit over the seal.

 

Rick

Why cutting a slot and putting a hose clamp? The pipe is a just bit too big?

I decided not to change the springs this time so this is why I started my first question saying it!

 

You adjust the Outside Diameter of the PVC Pipe, ... to fit the Inside Diameter of the Lower Fork where the Seal gets placed.

 

Makes sense, thanks.

 

if you leave the pvc pipe longer than the inner fork you can tap the top of the pvc and not take a chance of hitting the forks you just worked on

 

Good tip, thanks Polock!

 

Put some cold weld on the forks yesterday evening, after using a propane torch to burn oil residues.

It seems to hold well. NOw I'd like to know if I can sand it the same way as the fork itself: 400 grit, then 800, 1000, 1500, 2000 is appropriate.

 

Here is a thread with pictures of every piece of my XJ750-RJ anti-dive forks laid out.
http://xjbikes.com/Forums/viewtopic/t=41895.html

The majority of the wear wont be where the dust seals are, the wear occurs at the bushings. I bought a shotgun bore cleaning kit and used the cloth pad to polish the inside of the lower fork tubes. Rubbing compund first then polishing compound. I would suggest buffing and polishing the outside of the upper fork tubes if you sand them, and make sure you crosshatch your sanding pattern, going up/down or sideways will be more likely to create ridges.


To insert your new fork seals, place the old fork seals upside down on top of the new ones and then use pvc to hammer it down. The old seals make an excellent washer.

 

Your forks and mine are a little bit different, but that gives a good idea, thanks for the link.

As for the sanding, I did it with my palm and fingers wrapped around the tube, to avoid making flat spot.

Sanding with 2000 grit wet is pretty close to polishing, I guessm but I may finish with AUtosol on a clean rag.

 

I'm a bit puzzled now.

I'm trying to reassembly my forks and I'm not able to align the hole at the bottom of the damper rod and the hole at the bottom of the anti-dive device. I can barely see a very small part of the bottom hole of the damper rod. I

it seems like the damper rod isn't sitting low enough in the lower leg, but I can't move it any further anyhow.

I didn't notice if it was that way when I disassemblied, it was hard to see with all the dirty oil in there.

Am I missing something?

 

I won't have access to my computer until Monday so I can't post any picture...

 

So I got my computer bac today, here is a link that will help (I hope so) telling me what I'm doing wrong:

tinyurl.com/kgfs2oj

The way I tried to reassembly the forks I can't align the lower hole of the damper rod and the lower hole of the anti-dive...

 

que,

Your link didn't work.

Gary

Edit: Ok, thanks.

 

It will work if you open another web page and if you copy and paste it at the place you'd put the site address normally

 

I'm back with Google Chrome, it works better to load pictures from photobucket:













Now if someone would point at what I'm doing wrong with fork reassembly, I'd appreciate a lot.

 

I'll look in the manual and see if it says anything.....

dave

 

I followed instructions in the manual but maybe I just misunderstood something...

 

Soooo, does anyone have an answer for me ?

 

This is great info!!!!! Im gonna fix my front suspension in a week or so.....just waiting for the springs....ty so very much for all this pics and info!!!!

 

Ok ive fixed my front suspension now.....new gaskets....i even got new progressive springs for it but it didnt work.....they made worse noise than my 20 yo garagedoor. Found out that they where almost 2 mm smaller in width so they didnt stay centered in the bottom and was shaped like a snake.....man i was pissed but my dealer took them back and gonna check it all out....something is wrong and according to him they should not have a smaller diameter. Got my money back and installed the old springs that where like new ones after messuring them. So no oilfilm on my forks and im riding happy again!!!