Here we go! Fork seals at 40k

[JohnK]

Kinda surprised they lasted this long. - studied up and getting it disassembled - posted the pick for others who may discover this kind of soiling before it pours out and causes other issues. It will require a full clean up and inspection of the wheel bearings, brake and smc - since it’s apart may as well go for the whole job.
Last time I had it that far apart was in IGOFAR garage that was around 20k on the clock. Pic below at IGOFAR years ago

I’m Swapping out stock for race tech springs front and rear rated for my heavy arse this time.

 

[dlim]

Damn John! You got a serious project there in front of you! It'll be good practice and review for you before I come over and have you help me with mine! Good luck!

 

[ToddC]

Yahoo!! You go John!
T

 

[JohnK]

Damn John! You got a serious project there in front of you! It'll be good practice and review for you before I come over and have you help me with mine! Good luck!

Hah luck ain’t gonna cut it. Time to go where most fear !! But it ought ride much better when loaded now. I’ll take a few picks along the way

 

[SMSW]

It's probably a bit late, but you should have considered gold valves up front since you are tearing it all apart and upping the spring rate. Be sure to check the sag when you are finished.

 

[Al Gully]

Nice seeing your bike hovering on 2 stands.

My seals leaked at 43,000 miles also, May 2022 , got another 7,000 miles out of them by cleaning them with a thin plastic sheet wrapped around the chrome slider.
I'm hovering around 50,000 miles April 2023, just started leaking again.
My new OEM seals just arrived today in Blaine WA today.
Picked them up from partzilla, free shipping.

 

[TerryS]

Not wanting to teach you to suck eggs but I have done a few forks in my time. Here's my tips:

• With the forks out but not disassembled, crack the allen head bolts loose on the bottom of the fork first, a rattle gun can be the best choice here as the bolts have threadlock and can be a royal PITA to free up. When you get the fork fully disassembled, clean the threads of the bolt and the damper base carefully (I use a tap and die) so that they reassemble smoothly without binding. Use a new copper washer to seal these (or you can anneal the old washers to make them more malleable and re-usable). I use a dab of blue Loctite on the thread when reassembling.
• Check your fork tubes carefully in the rock-exposed zone for any craters that are cutting the seal. Dress these down carefully so there are no projecting jagged bits.
• Put the cut corner of a plastic bag over the fork tube end when sliding the new seal on so as not to damage the lips.
• If you don't have a proper fork seal driver you can make one with a piece of suitable PVC pipe. You can also use the old seal to protect the new one during driving. Rubber grease is your friend here too.
• If you are in that far it is not a big deal to open the cartridge and properly clean out all the gunge that hides in there. If you push in the damper base you expose a circlip, pop that out and then the damper base can be extracted exposing the compression shim stack, and you can push the damper rod through to expose the rebound stack too. Just be careful not to damage the o-ring and piston seal when you reassemble.

 

[Larry Fine]

I did my '96 Nighthawk 750 in '14. Made a great ride and handling improvement.

 

[JohnK]

Nice seeing your bike hovering on 2 stands.

My seals leaked at 43,000 miles also, May 2022 , got another 7,000 miles out of them by cleaning them with a thin plastic sheet wrapped around the chrome slider.
I'm hovering around 50,000 miles April 2023, just started leaking again.
My new OEM seals just arrived today in Blaine WA today.
Picked them up from partzilla, free shipping.

I tried that but closer inspection showed the left fork was wet and weeping with use. I’m in Bonney Lake - welcome to come by and use the shop.

 

[JohnK]

Not wanting to teach you to suck eggs but I have done a few forks in my time. Here's my tips:

• With the forks out but not disassembled, crack the allen head bolts loose on the bottom of the fork first, a rattle gun can be the best choice here as the bolts have threadlock and can be a royal PITA to free up. When you get the fork fully disassembled, clean the threads of the bolt and the damper base carefully (I use a tap and die) so that they reassemble smoothly without binding. Use a new copper washer to seal these (or you can anneal the old washers to make them more malleable and re-usable). I use a dab of blue Loctite on the thread when reassembling.
• Check your fork tubes carefully in the rock-exposed zone for any craters that are cutting the seal. Dress these down carefully so there are no projecting jagged bits.
• Put the cut corner of a plastic bag over the fork tube end when sliding the new seal on so as not to damage the lips.
• If you don't have a proper fork seal driver you can make one with a piece of suitable PVC pipe. You can also use the old seal to protect the new one during driving. Rubber grease is your friend here too.
• If you are in that far it is not a big deal to open the cartridge and properly clean out all the gunge that hides in there. If you push in the damper base you expose a circlip, pop that out and then the damper base can be extracted exposing the compression shim stack, and you can push the damper rod through to expose the rebound stack too. Just be careful not to damage the o-ring and piston seal when you reassemble.

Yup - Yup and yes sir. Have the oem shop manual to keep me guided. Also I invested in a motion pro seal driver and a bullet to protect the seal. All new seals, dust rings and washers - hope to find the innards in good order the current damper seems really strong

 

[JohnK]

I did my '96 Nighthawk 750 in '14. Made a great ride and handling improvement.

The tie off !

 

[Al Gully]

I did my '96 Nighthawk 750 in '14. Made a great ride and handling improvement.

Awesome pictures, looks like someone took a blow torch to your seal area at first glance.

 

[Al Gully]

welcome to come by and use the shop.

Sounds like a plan, if I do so before changing the fork seals, I might have to put a few diapers on the fork tubes.
Heck, the rider might need a diaper too for the long haul with no stops.

 

[SMSW]

Larry uses an old triple clamp held in a vise to secure the fork legs while he works on them. Not having one, I drilled a hole through a short piece of 2 x 4 (maybe a foot long), used a drum sander to enlarge it to a sliding fit w/ the fork leg, then ran my table saw blade longitudinally through the hole. A bolt thru a hole crosswise allows me to tighten this wood 'clamp' around the fork leg. I clamp the 2 x 4 in my bench vise and voila - a makeshift triple clamp.

 

[JohnK]

Left fork the leaker gonna need new bushings too. All the Teflon was worn off. Springs are good though - measured 9 7/8” may sell them for those who need stock springs -

 

[JohnK]

Larry uses an old triple clamp held in a vise to secure the fork legs while he works on them. Not having one, I drilled a hole through a short piece of 2 x 4 (maybe a foot long), used a drum sander to enlarge it to a sliding fit w/ the fork leg, then ran my table saw blade longitudinally through the hole. A bolt thru a hole crosswise allows me to tighten this wood 'clamp' around the fork leg. I clamp the 2 x 4 in my bench vise and voila - a makeshift triple clamp.

He gave me one - will come in handy

 

[dlim]

Looks like youre in the middle of surgery again. For those that don't know, John's shop is legit! He's got just about every tool you'll need to get your ST running in top shape. He's helped me quite a bit as a new ST owner, and a great ambassador of this forum. I feel tech day is not too far off John!

 

[JohnK]

Looks like youre in the middle of surgery again. For those that don't know, John's shop is legit! He's got just about every tool you'll need to get your ST running in top shape. He's helped me quite a bit as a new ST owner, and a great ambassador of this forum. I feel tech day is not too far off John!

Shucks Dave - thank you but not every tool however I will invest in any that we may need in the future. A tech day may be in order soon. I still go to IGOFAR for counsel and advice. Now there’s a fellow with all the tools and knowledge along with many others here. I am thankful and appreciate this group of good folks - together we are the best.

 

[Igofar]

Kinda surprised they lasted this long. - studied up and getting it disassembled - posted the pick for others who may discover this kind of soiling before it pours out and causes other issues. It will require a full clean up and inspection of the wheel bearings, brake and smc - since it’s apart may as well go for the whole job.
Last time I had it that far apart was in IGOFAR garage that was around 20k on the clock. Pic below at IGOFAR years ago

I’m Swapping out stock for race tech springs front and rear rated for my heavy arse this time.

That picture brings back memories…..I can see my wax bath for my hands on the shelf.
My poor hands were so cut up after the surgery, that I had no grip strength for holding wrenches and had to soak my hands between jobs.
Thanks for that memory John

 

[JohnK]

from this perspective - I ask myself What have you gotten yourself into. Forks coming along nicely with new springs, SMC still smooth and clean - bled the brakes and the pistons and calipers are all clean. Did you know that a paint stir stick from Home Depot is the same thickness of the disc? I like to have the pads set before we put it all together.