Another Run at Fork Seals

[GIXERHP]

This is a VERY IMPORTANT step!

You left out one important step Charlie. Pumping the oil out of the cartridge. The piston inside the cartridge is filled with oil. You should place the cartridge on a folded towel and pump that puppy until all the oil is removed. If you miss this step, the fork will be overfilled with the addition of 512 ml of oil.

By increasing the oil level in the fork it leaves less air space. This air space is compressed as the fork travels through its stroke. As the air pressure is increased this acts like an overload spring and gives the spring more resistance as it nears the bottom of the stroke. Makes the fork act like it has a progressive spring. If this air pressure is to great it will blow the seal out prematurely.

So if you are going to use this method to replace the seal it's very important to remove ALL the oil from the cartridge!

Motion Pro - Damping Rod Tool

Failure to do this step, will only cost you another set of seals down the road!

 

[Josh]

It was pretty easy wasnt it.Hardest part for me was opening the lower clamp enough to get the tube to slide out.The rest was simple.My forks feel so much better now.

The hardest part was taking all the plastic off, lol.

Two notes from my Gen 1 job:

The fork drain bolt is 10mm
Each fork takes 480ml of fork oil

 

[Trout]

Notes from my Gen 1 fork seal job:

First of all, thanks for the write-up. It's very helpful.

The only piece of plastic that really needs to be removed (besides the front fender) is the piece of black plastic under the chin of the front fairing. With this piece removed, along with the fender and the wheel, it's easy to sneak a torque wrench up from underneath to get the bottom fork clamp bolts.

The header tubes are exposed with the side fairings installed, and the front of the bike can be lifted on the header tubes.

The damping rod tool, (Motion Pro link a couple of posts above), can be substituted with a medium to long piece of rubber hose. I used a piece (1/2", I think) forced over the threads on the top of the damper rod. This tool is only required if you take the forks apart according to the manual. If you follow the instructions in this thread, then you don't need this tool (or the rubber hose).

The fluid capacity listed in the manual is for a DRY fork... one that has been dis-assembled, cleaned with solvent, dried, and re-assembled. Even if you pump the damper rod until you are blue in the face, there is oil that remains in the fork. The amount of remaining fluid is significant. I did the fork seals using the traditional method (by the book), using the special homemade tools to compress the spring, etc. I re-filled with the amount specified in the Suzuki factory manual (480 ml, or 16.2 US oz. per fork). The manual then says to use the special tool to set the fluid level to 3.9" from the top of the tube. I sucked out at least 2 oz. from each tube to get the 3.9" level. I used a 60cc syringe that I got from my local farm supply store (in the veterinary section). $2.

In other words, if you follow the instructions outlined in this thread (tube separation using the 10mm bolt on the bottom), and if you pump the cartridge to empty the oil, and if you refill using the amount specified in the manual, then your forks will be OVERFILLED. It's not possible to measure the level with the spring in the tube. You have to guess, or just be happy with getting it in the ballpark.

Looking back, I should have figured out the exact amount I ended up pouring into each tube so that next time I can use this shortcut method. Actually, now that I have the homemade Suzuki special tools, I don't think there will be any significant time saved by doing it the other way.

 

[busacaptain]

Ok, I'm a bit confused here on the filling procedure. The write up in the do-it-yourself section says to fill till the 3.9" level then install the spring and this one is with the spring in place.

 

[HOOKDADDY]

You left out one important step Charlie. Pumping the oil out of the cartridge. The piston inside the cartridge is filled with oil. You should place the cartridge on a folded towel and pump that puppy until all the oil is removed. If you miss this step, the fork will be overfilled with the addition of 512 ml of oil.

By increasing the oil level in the fork it leaves less air space. This air space is compressed as the fork travels through its stroke. As the air pressure is increased this acts like an overload spring and gives the spring more resistance as it nears the bottom of the stroke. Makes the fork act like it has a progressive spring. If this air pressure is to great it will blow the seal out prematurely.

So if you are going to use this method to replace the seal it's very important to remove ALL the oil from the cartridge!

nice 1

 

[Kat600]

Hey everyone, a good friend of mine helped with my fork rebuild over the winter. Along with new seals and oil, I also went to stiffer springs. He spent $90 on this kit: Fork Service Tool Kit and it includes everything you would need for conventional forks. He's changed 2 sets of forks on his bikes as well as mine so the tool kit has long since paid for itself. I'll probably be grabbing one of these as well as it will pay for itself after one change. You can most likely make the tools yourself, but you can't go wrong for $90.

 

[mprocto]

Does this write up apply to gen 1 hayabusa (2001). Also, is a fork spring compression tool required to replace just the fork seals?

 

[Bigdawg76]

I also have to do this. How much should I expect to pay. Service shop near me wants about 80 for all 4 seals, and that's not including the oil. Is that price right?

 

[sailboatjoe]

Great write up. I printed it out and followed it step by step. I even pumped out the old oil from the cartrage. Hole job took me less than hour hours and that included the time to figure out the tricky bits. also I didnt even have to take the fairings off the bike.

 

[Twobrothersbusa]

Great write up. I printed it out and followed it step by step. I even pumped out the old oil from the cartrage. Hole job took me less than hour hours and that included the time to figure out the tricky bits. also I didnt even have to take the fairings off the bike.

Glad it worked out for you!

 

[888 HAYABUSA]

great topik..thanks for the pics..very usefull

 

[bababusa]

Nice ...Whats the weight oil used to refill ...?? 5w ???
Thanks

 

[Twobrothersbusa]

Google fork oil...there are tons of different weights. I think stock is L01 Suzuki oil which is supposed to be around a 5 equivalent.

 

[SLEEPERBUSA]

It was pretty easy wasnt it.Hardest part for me was opening the lower clamp enough to get the tube to slide out.The rest was simple.My forks feel so much better now.

Here's what I did.
Remove the pinch bolts completely. Thread them in from the opposite direction. Slide 2 coins between the threaded end of the bolt, and the side that they were originally in. Tighten each bolt slightly, one at a time, It will push the clamp apart, and tube goes right in and out. No problem.

 

[Tufbusa]

The easy way to do that is to use a large flat screw driver. Push it into the gap once the pinch bolts are removed, pry slightly and the fork slides right out. Same going back in. Pry slightly with the screw driver while sliding the fort tube into position.

I like your ingenuity!

 

[SLEEPERBUSA]

Hey, I had a wrench and 2 nickles. What would McGiver do?

 

[SLEEPERBUSA]

Actually, I did it that way because I had the forks ceramic coated black, and ceramic coating scratches and scuffs very easily, so I needed them to not touch at all going back in. I didn't wanna take the chance with a screwdriver in one hand and the fork in the other. I've been told that I'm not very stable...
The bolt/nickle trick allows you to get it as wide as need be and use both hands to slide the fork thru without touching the sides.

 

[MOCKIN U]

OK. Here we go gang. My fat bottom girl gave me a surprise on Monday after a nice long weekend of riding and really not feeling quite right. She was a little stiff going over bumps and such so I was alert to something being up. I got home and the left fork had oil drips/spots on it I was like okay result found. Monday went to go check on it and poof big ol oil spot on the ground as the seal let go completely.

Well, I have stripped the engine out of my old gixxer and put that whole thing back together. Done brakes and many exhaust changes on this one. STILL I feared the fork seals. They are critical to performance right? Dont wanna screw that up plus dont want them to spring out of control and bop me in the face or something.

Then I started to do some searching here and found posts on make this tool, buy that tool, and so on and I was nervous. I then found this post by Charlie. I read up a bit and sent him a clarifying message. This procedure is peformed when you do not have to maintenance the springs in anyway you just need to do the seals and such. No tools are needed to be made for this procedure "Dust seals the easy way" if you must do work on your springs or upgrade them then the other method is what you need the tools required for this job are posted above nothing else is required in anyway. If you want to just replace your leaky seals then please......

Jack up your pride and joy and gently rest the exhaust on wood blocks so she is stable or use a stem stand as many others have and attack this job. LISTEN CLOSE......... IN MY OPINION THE WORST IS LIFTING HER UP!!!

DID YOU HEAR THAT? The job is so easy and straight forward that the hardest part is lifting her up and making sure she is stable. The forks come out really easy and smooth. just pay attention to what you are doing and dont force anything. The only part that had me snagged was getting the drain plug out. No matter what I did the dang thing just turned and turned. I thought I was compressing the fork far enough to jam it up enough to spin loose but I wasnt. A friend came over and I gave her my impact. Shes a gear head and rider and I put my muscle into compressing the fork into a couple rags on a foam mat (not on concrete be smart) dont wanna damage the adjustment screws on top.....once i compressed the fork she hit the impact and out it came. Then the 30mm nut on top spun free with a quick impact hit and out all the components came nice and smooth all under my control and no surprises. Of course I drained the oil and made sure to cycle the spring unit to get extra fluid out of it. Going back together will be soo dang easy now that I see how it works.

Gang,

Dont be afraid of this job. If you can change any wheels on your machine or adjust your chain properly then you can do this job. Its just that routine. SERIOUSLY!

Thanks Charlie (TwoBrothersBusa)

 

[Twobrothersbusa]

Thanks for posting...glad it worked out for ya!

 

[Twobrothersbusa]

And to roll it back around thanks to SteveO (TufBusa) for getting me through my first set!