Topic: Fork rebuild FUBAR

[Laminar]

The tube won't go back into the bottom (snicker).

I finished re-jetting, cleaning the carbs, replacing the air filter, and fixing the cam chain tensioner on my 750K7 with little to no trouble and was feeling pretty good about myself so I decided to go ahead and tackle the fork seals while I was at it. Terrible idea.

They were leaking to the point that the lower tubes constantly had oil and grime on them from fork oil running down the backs, and I'd occasionally find a few drips on the ground. I got the first tube disassembled fine until it came time to pull the seal out of the lower tube. With some careful (read: careless) work with a screwdriver and hammer, I finally managed to get the seal out. I tried drilling a couple tiny holes in the seal, inserting a wood screw, and prying slowly (as I saw recommended here), but the screw just sheared and ended up inside of the seal.

I got everything cleaned up and went to put the upper tube back into the lower tube, but it wouldn't go. There seemed to be some interference that wouldn't let it go. I cleaned it off again, dremeled the tiniest chamfer in the inside rim of the lower tube, and made sure that both the inside surface of the lower tube and the outside surface of the upper tube were smooth and free of any burrs or nicks. I coated everything with some fresh ATF and tried again. It was the tiniest bit easier, but still got stuck after I got about an inch of it in.

Where did I go wrong? The Honda manual doesn't go into a ton of depth as far as this process was concerned, and I've already swapped seals on my Nighthawk without issue, so I'm not sure what I could have done. Thoughts? Comments? Suggestions? Innuendo?

[JohnG]

do you get past the seal   If no, are you sure they sent you the right size seals??

How about if you leave the spring out and do a dummy run??  or even remove the damper and the spring and try it??

[754]

If the tubes got dropped , you may have a nick or burr on them... I cant see  it hanging up if it pulled out freely before.

 Is there a nick or burr on the top edge of the hole the forktube goes in.. Ie mark from screwdriver when puling the seal?

[markjenn]

I'm confused about what happened.  Did you drive the new seals in?  And now the inner tube won't go past the seals?

- Mark

[Toxic]

Either the wrong seals or the seals are deformed from the Mfg.

Or you put a burr on the surface where the seal rest in the lower tube.
Any kind of scratch or burr will deform the seal.

The seal needs a perfectly smooth surface in the fork lower.

Take it out and examine.

[Laminar]

Even without the seal involved at all, the upper tube won't go into the lower tube. I measured the seal and it's within spec.

I'm in Curasao for work for the next couple days so I can't try anything yet. I might just have to pick up a new lower tube.

[manjisann]

Can you post pics? I've rebuild 3 sets of tubes this year and agree with everyone, if it came out smooth it should go back in smooth unless something changed. The clearance between the tube and walls of the lower fork is pretty tight so it wouldn't take much to hang it up.

Brandon

[754]

I have seen this;
 aftermarket or sent out for chrome forks, a bit oversize, can fit very tight, had to hone 1 set to make them fit.

 But in this case, probably there is a nick or burr overlooked, does not take much to hang up when your clearance is the thickness of a hair..

[Laminar]

Alright, I'll check it out when I get home, probably thursday. I'm stuck on an island in the caribbean until then. Life is rough.

[Laminar]

Alright, so I believe it was the fault of some surface imperfections on the inside of the lower tube. I took a fine sanding drum on the cordless Dremel at low speed and smoothed it all out from the inner top lip down about a centimeter. After that the upper tube slid in nicely.

For the second fork, I "splurged" and picked up a real seal puller for $11 at Autozone. Best. Purchase. Ever. No more hammering, cutting, shooting screwdrivers across the garage. I just put the lower tube in my vise and gently pulled the seal out. Of course, that was after removing the rolled up paper towel the PO had put under the dust boot to stop the fork seal from leaking instead of, you know, replacing the seal.

I put everything back together and it appears to be working great.

[Duke McDukiedook]

Yeah, I had an Einsteinian PO slip a piece of a pop can in my old fork seal. 

[754]

Explain the seal puller.. I assume you used a pas under it..

 I never have trouble with the screw method, and it only takes like 5 or 10 minutes for a pair of forks, not sure why it did not work for you.

 cleaning up burrs.. sanding can take material off where you want it to stay, better to find the high spots and carefully work en off.. with a ball burr or scraper..

[Gorms]

Am I understanding it right that you are having trouble getting the seal out?  Once you take the inards out and uncrew the allen bolt underneath, just yank the lower tube from the upper tube,  There is a collar at the bottom of the upper tube that will yank the seal out when you pull.

[754]

Gorms, that only works till end of 72.

[Gorms]

Really?  I just did this to my friends 1980's GL500.  I looked at the exploded diagram for my 77 cb550 and it appeared as though it would work also.

[754]

It may work on 550, but not on 73 & later 750..

[Laminar]

Am I understanding it right that you are having trouble getting the seal out?  Once you take the inards out and uncrew the allen bolt underneath, just yank the lower tube from the upper tube,  There is a collar at the bottom of the upper tube that will yank the seal out when you pull.

That's how my Nighthawk 550 worked. This is different though -- you can pull the upper tube out of the lower and the seal will still be in the lower. Get a seal puller. Save time.

[Gorms]

Gotcha. Good to know.