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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: sh00ter on April 17, 2012, 03:35:49 PM

Title: Fork oily
Post by: sh00ter on April 17, 2012, 03:35:49 PM
After riding this weekend I noticed the right hand fork had quite an oily patch on it and on the top cup of the fork slider.   I'm wondering if this is a sign of impending seal failure or might they be already failed?  How do I know?   I wiped it down, but haven't ridden it since to know if it still leaks.   I was thinking I'd drain the oil and see how much came out - but maybe if I'm at it, I should just take them apart and do the seals? 

Any insight much appreciated.   :bmwsmile
Title: Re: Fork oily
Post by: Rick G on April 17, 2012, 07:36:14 PM
If there is oil there it has already failed just a matter of time as to when it gets critical and has to be fixed. Seals are cgeap and doing it yourself is a good opportunity to check the whole front end over.
Title: Re: Fork oily
Post by: sh00ter on April 18, 2012, 07:47:55 AM
If there is oil there it has already failed just a matter of time as to when it gets critical and has to be fixed. Seals are cgeap and doing it yourself is a good opportunity to check the whole front end over.

Thx!  Could someone tell me, before I tear it apart, what parts I need to replace? Then I can get them on hand before the weekend.  Thanks all!
Title: Re: Fork oily
Post by: Scott_ on April 18, 2012, 07:51:31 AM
How many miles on that steed.
Title: Re: Fork oily
Post by: robleyd on April 18, 2012, 09:08:43 AM
Quote
Could someone tell me, before I tear it apart, what parts I need to replace

Fork seals for sure - as for the rest you won't know until you pull it apart. You possibly will need top and/or bottom fork bushes; and there is a slim chance there might be pitting on the fork legs which might require repair.
 
Title: Re: Fork oily
Post by: sh00ter on April 18, 2012, 09:42:36 AM
Quote
Could someone tell me, before I tear it apart, what parts I need to replace

Fork seals for sure - as for the rest you won't know until you pull it apart. You possibly will need top and/or bottom fork bushes; and there is a slim chance there might be pitting on the fork legs which might require repair.

Thanks for the reply.   Bear with my noob-ness, want to make sure we're talking apples & apples ...

From the clymer book this diagram - are the seals you refer to #15?  and the bushings, 9 & 17?

(http://i.imgur.com/pXytI.jpg?1)

Much obliged  :yes
Title: Re: Fork oily
Post by: sh00ter on April 18, 2012, 09:43:47 AM
Hey Scott,

There are 14k original ('94 model)  - I believe the bike did sit for extended periods in it's 18 years, so I'm guessing that the seals might be dry-ish, just guessing though.  I've only put a hundred or so miles on it, and in my going over the ride the other day I noticed this very oily tube ...

How many miles on that steed.
Title: Re: Fork oily
Post by: Inge K. on April 18, 2012, 10:50:39 AM
You`re correct about part # 9,15 & 17, I would also have changed #13 (dust seal) while things are apart.

Before ordering, lift the dust seals on both sides and check the snap ring (#14).
If these ones been exposed to water over time it could be heavy rusted, and could possibly break when
dismantling.

Inge K.
Title: Re: Fork oily
Post by: sh00ter on April 18, 2012, 10:53:10 AM
Any special tools I'll need?  The book mentions a special tools to diassemble the fork tube (stachion?) and also one to seat the seal.  I'm guessing these can be worked around and that I don't need to disassemble it that far?  Thanks for helping out with the million questions  :loopy: :loopy:
Title: Re: Fork oily
Post by: frankenduck on April 18, 2012, 12:52:49 PM
It's possible that it's just some crud trapped in the fork seal.  Try using a thin feeler gauge around the fork seal to see if you can dislodge what might be trapped in there.
Title: Re: Fork oily
Post by: sh00ter on April 18, 2012, 01:02:36 PM
It's possible that it's just some crud trapped in the fork seal.  Try using a thin feeler gauge around the fork seal to see if you can dislodge what might be trapped in there.

Thanks!   I read that elsewhere too, I'll do that then just change the oil in the forks as they sit, ride it and see what happens first.   I assume if one does buy the farm, that it'll be fairly obvious  ....
Title: Re: Fork oily
Post by: Scott_ on April 18, 2012, 08:19:21 PM
Hey Scott,

There are 14k original ('94 model)  - I believe the bike did sit for extended periods in it's 18 years, so I'm guessing that the seals might be dry-ish, just guessing though.  I've only put a hundred or so miles on it, and in my going over the ride the other day I noticed this very oily tube ...

How many miles on that steed.
At only 14K I wouldn't think you would need the bushings.
Like was mentioned above check the tubes for pitting, dried bug guts, etc.....
The seals aren't too bad, about $17, and the dust caps are a little more $24 or so each.
Title: Re: Fork oily
Post by: sh00ter on April 18, 2012, 08:23:20 PM
Hey Scott,

There are 14k original ('94 model)  - I believe the bike did sit for extended periods in it's 18 years, so I'm guessing that the seals might be dry-ish, just guessing though.  I've only put a hundred or so miles on it, and in my going over the ride the other day I noticed this very oily tube ...

How many miles on that steed.
At only 14K I wouldn't think you would need the bushings.
Like was mentioned above check the tubes for pitting, dried bug guts, etc.....
The seals aren't too bad, about $17, and the dust caps are a little more $24 or so each.

Well, I ordered the whole she-bang, $220 for the seals, bushings, caps and o'rings... (they're irish)

Figured if i'm going in, i hate not having parts i might need.  How to know if the bushings need replacin' once I'm in?
Title: Re: Fork oily
Post by: mystic red on April 18, 2012, 08:34:09 PM
Compare them with the new ones. I'm with the other Scott, probably don't need to do the bushings but if you are going to keep the bike awhile, throw them in the parts bin cause you will at about 40Kish.
Title: Re: Fork oily
Post by: Jumpin Jimmy B on April 18, 2012, 09:25:30 PM
 Fork seal fun!
 Well, you ordered all the parts, but I'm thinking you will not need those bushings. Dust seals, seal itself & maybe the snap rings. Not sure where you live/ride, but consider adding fork boots.
 My 93 was all good for about a year. I thought WTH is with all the beatching about fork seals on these beasts. Then I popped one, then the other started leaking.
 Now I am PO'd. So I pull it all apart, both sides, no bushings though. Cleaned it all real good. Like hot soapy water and dry me overnight clean. Then before I put her
all back together, just for chits & grins added new fork springs I got for a steal, Man O man what a DIFFERANCE!!!!

 Been almost 2 years and 18,000 miles, 53K total on the bike, and it feels just like the day I did the springs. Forks are clean and pretty when I check under the boots. Will change the fork oil this year. I ride in all kinds of mid west nasty. Rain & road construction and all that jazz.

 Try cleaning that seal, order the fork boots, Rancho 1952 I think on Amazon.com, the do the whole job and be happy longer.
http://www.amazon.com/Rancho-RS1952-Shock-Boot/dp/B000CPCCFY (http://www.amazon.com/Rancho-RS1952-Shock-Boot/dp/B000CPCCFY)


 Looks like this. I painted some stainless steel hose clamps with truck bed liner to black them out. If you decide to use these they may need to be vented. Mine did not have vent holes so I made my own.

(http://i292.photobucket.com/albums/mm6/jpberens1993K1100RS/IMG00066.jpg)

 Good luck! :biggrin:
Title: Re: Fork oily
Post by: sh00ter on April 19, 2012, 11:15:42 AM
Fork seal fun!
 Well, you ordered all the parts, but I'm thinking you will not need those bushings. Dust seals, seal itself & maybe the snap rings. Not sure where you live/ride, but consider adding fork boots.
 My 93 was all good for about a year. I thought WTH is with all the beatching about fork seals on these beasts. Then I popped one, then the other started leaking.
 Now I am PO'd. So I pull it all apart, both sides, no bushings though. Cleaned it all real good. Like hot soapy water and dry me overnight clean. Then before I put her
all back together, just for chits & grins added new fork springs I got for a steal, Man O man what a DIFFERANCE!!!!

 Been almost 2 years and 18,000 miles, 53K total on the bike, and it feels just like the day I did the springs. Forks are clean and pretty when I check under the boots. Will change the fork oil this year. I ride in all kinds of mid west nasty. Rain & road construction and all that jazz.

 Try cleaning that seal, order the fork boots, Rancho 1952 I think on Amazon.com, the do the whole job and be happy longer.
http://www.amazon.com/Rancho-RS1952-Shock-Boot/dp/B000CPCCFY (http://www.amazon.com/Rancho-RS1952-Shock-Boot/dp/B000CPCCFY)


 Looks like this. I painted some stainless steel hose clamps with truck bed liner to black them out. If you decide to use these they may need to be vented. Mine did not have vent holes so I made my own.

 Good luck! :biggrin:

Really good advice, thanks.  I got the forks torn apart last night, I think you're right on all counts - I think the dust covers might even be reusable.   There was some pretty good grey-ish sludge (tech term?) that came out of the bottom of the bottoms; I'm thinking i'll polish it all up real good then reassemble. 

It seems that if I do not disassemble the damper, I do not need to add the extra 50ML of fluid to the left one when I reassemble, is that correct?

Nice Boots; I've heard that I need to do that, I'm ordering those today.   
Title: Re: Fork oily
Post by: Jumpin Jimmy B on April 19, 2012, 01:06:05 PM
 Some folks don't like the fork boots look, I kinda agree, but on our darker color bikes it is AOK.

 The blacked out look really makes the front of the bike look compact.

 I think the oil would drain out of the dampners? I used the extra oil.

Yeah, mega super silver sludge in mine too when I pulled it all apart.

 I also had my wheels black powder coated. Kinda excessive, but the crappy silver paint was NOT holding up after 19 years.
Title: Re: Fork oily
Post by: sh00ter on April 19, 2012, 01:52:39 PM
I also had my wheels black powder coated. Kinda excessive, but the crappy silver paint was NOT holding up after 19 years.

I'd love to see photos of that, the blacked out look is pretty cool .. . . .
Title: Re: Fork oily
Post by: wmax351 on April 19, 2012, 03:20:09 PM
The fork boots look great on naked bikes. Especially red ones. Red and Black go together well. And the forks and headlight ring are the only chrome on the whole bike, which kinda looks out of place.
Title: Fork Boots for K75S
Post by: GasStation on April 21, 2012, 09:50:43 AM
They make those for K75S too? Anyone with pics of his K75S with boots?
Title: Re: Fork oily
Post by: mystic red on April 21, 2012, 10:45:20 AM
Quote
It seems that if I do not disassemble the damper, I do not need to add the extra 50ML of fluid to the left one when I reassemble, is that correct?

Correct.
Title: Re: Fork Boots for K75S
Post by: frankenduck on April 21, 2012, 10:51:12 AM
They make those for K75S too? Anyone with pics of his K75S with boots?


(http://home.comcast.net/~sumdumguy/91k75s/K75pics_conv/leftside3.jpg)