Topic: CB750 Fork re-assembly... Question and Pics...

[sbparks]

Folks,

 This is a turning point for me.  I'm actually asking a question about how to put something back together, not how to take it apart!

 I'm in the process of putting my forks back together.  I see how everything fits - All makes sense, so far.

 I'm not sure about the fork seals... Which end goes up (in the fork tube)?

 As I look at the edge of the seals I do see that there is a raised edge (the circumference is slightly larger).  Should this raised edge go in first or behind?

 The first picture shows the difference in circumference.  The second shows the edge with the larger circumference.  The third shows the smaller circumference and has some lettering on it. 

 Which side goes in the tube first?

 The seal is the Honda part: 91255-KBH-003

 Thanks for the help!

Scott

[Johnie]

The lettering goes up is what I learned from this board.

[MCRider]

The open side of any seal always goes towards the oil.

PS: I'm sure there's an exception to prove me wrong. Like valve seals.  Other than that, I'm right.   

[BeSeeingYou]

The open side of any seal always goes towards the oil.

PS: I'm sure there's an exception to prove me wrong. Like valve seals.  Other than that, I'm right.   

I would agree with this.  I recently did the ones on my XS650 and that is how the old ones came out and the new ones went in.  If you have access to a bar clamp and something just slightly smaller in diameter than the seal this is a good way to put them in.  Mine were very tight coming out and going in.

[sbparks]

Hey Guys,

 I'm still not convinced!

 I don't know if you can tell by my pictures, but both of the sides of the seal are open.  There appears to be a wiper on both the top and the bottom (you can see two springs that keep the wipers tight).

 I would think that the larger circumference side would go up in the fork tube.  This would mean the letters would be facing down (if my assertion is true).

 Any thoughts?  Maybe I could post another picture that would help?

Scott

[MCRider]

"both sides of the seal are open"

Yikes! I'm out.

[ekpent]

I to wondered about that. No spring or metal side etc-What brand are they?

[Johnie]

This is in the FAQ:

The seal should be installed with the seal lip facing upward(out). If installed improperly, upside down or damaged during installation, the seal can leak. It is important that the seal be driven into the lower fork case perfectly aligned and fully seated against the stop. If the seal is installed even slightly cocked or deformed by excessive force, it will leak. The seal lip would be angled against the fork tube causing rapid wear and elongation. If the sealing lip is damaged by the slightest nick, it too will cause leakage. It is important that the seal be installed using pressure only on the outer perimeter of the seal without contacting the sealing lip. The taper from the outer edge of the seal to the center sealing lip should be facing up. As a rule, seals are usually installed with the seal number facing out when used in a blind opening.
(from Warlock)

If you have some bad spots on the forks or if you install the seals from the bottom up The following trick may help.
I take a roll of wax paper (like from the Kitchen) and put a piece around any area that may damage the seal as I am positioning it. Put a little fork oil (Automatic Trans Fluid?) on the wax paper and seal and slide it over the tricky parts.
(from kghost)

[sbparks]

Guys,

 I appreciate the help.

 The seal is from Honda Parts Nation:  Honda part: 91255-KBH-003.

 I agree with the assertion that the seal lip should face the oil, but, my seals have two lips (sealing surfaces).  One, towards the oil, the other facing the other (dry side).  That's why I say the seal appears to have two open sides.  Its not as if the side with the letters/numbers is flat (closed). 

 I honestly think the seal would function in either direction, but there is no doubt a correct way to seat the seal.

 Any ideas?

SBP

[MasterChief750]

i would say, the side in your last image would be the side that faces up, and the side in your second image would be the one that faces the oil.

[Porscheguy912]

I just completed this operation last summer.
It is confusing because there are two lip edges and two springs.
I asked my self the same question too but it was because the old seals looked nothing like the new ones so I had no reference point at all.

Number or letters up. as it picture* DSC_0518.JPG.

If its upside down it WILL leak!

If you do it wrong, you will have much better luck getting the new ones out than you had with the old ones.
  Practice makes perfect!

Here's a link to my post with a few pics that may be of help. http://forums.sohc4.net/index.php?topic=55285.0

Guys,

 I appreciate the help.

 The seal is from Honda Parts Nation:  Honda part: 91255-KBH-003.

 I agree with the assertion that the seal lip should face the oil, but, my seals have two lips (sealing surfaces).  One, towards the oil, the other facing the other (dry side).  That's why I say the seal appears to have two open sides.  Its not as if the side with the letters/numbers is flat (closed).  

 I honestly think the seal would function in either direction, but there is no doubt a correct way to seat the seal.

 Any ideas?

SBP

[sbparks]

Mr. PorcheGuy,

 Thanks for sharing your experience with me.  I will mount the seal as you've described.

 Just to add another observation to this discussion...  My guess would have been to mount the seal in the other direction (that you described) based on this observation:  I would have put the seal into the opening with the larger diameter end trailing.  Also, notice that one end of the seal is actually champhered (beveled).  This champhered egde is opposite form the larger diameter edge.  I would have thought champhered edge first followed by larger end.

 Any comments?  I'm not as much questioning your experince as I am trying to understand the design of these seals.  They are made the way they are for a reason.  It would be cool to understand.

 None-the-less, ready to mount these seals with the lettering out.

 Thanks, Scott