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fork service

10K views 77 replies 14 participants last post by  RJ2112 
#1 ·
Just ordered up the motion pro cap socket tool, so I can open the forks and replace the oil.... Finally taking the plunge on a USD fork. More to follow when it shows up and I can get on with it.

From the shop manual, the oil change is straightforward enough, once you can take the caps off without damaging them.

It was surprising how much more expensive the Kawasaki tool was, than the Motion Pro tool.
 
#3 ·
I'm cheap, and lazy.... I don't think there is anything wrong with the bushings or seals. The oil is off viscosity, so my damping is all hosed up. No leaks, no looseness or other indication that the bushings need to be replaced.....

You're going to make me watch you tube videos to get a better understanding of this.:laugh
 
#4 ·
You wont know the bushings need to be replaced until you take the the forks apart. Which means you will need to remove the upper stanchion from the lower, which will require the seal to be bashed out of the upper stanchion. If you've put on a lot of miles before the last time the forks have been gone through, it might not be a bad idea to just replace everything.
 
#13 ·
Bushings you would be hard pressed to feel as "bad" until you have the forks apart cleaned and no seal and then slide it all back together- but at anything over 20k I bet you have a couple thousandths of slop, and you have originals in there at 50=K? you have more than 5 thousandths of sloppiness........ for $40 buy the damn bushings and put them in!
Even if you hack a measurement of thickness with a dial caliper you will measure more than 5 thou of difference new to your old........ I guarantee it!
Bike will work much better and you have oil travelling around the sloppy loose bushings now too, so not all of it is going through the damper rod making the system even less effective, not too mention all those wear particles in your oil and in your damper rod and in the compression and rebound stacks

full disassembly, cleaning to spotless then new parts and proper assembly!!! the only way to do it correctly!!!!
 
#17 ·
Yeah this really needs to happen the right way; and I will eventually get there. So far all I have on hand is the socket for the cap. At the least I want to have the oil and the level setting gizmo/syringe on hand before I do anything. the longer that progresses, the more likely I am to get all fo the tools and parts on hand before I break it down.
 
#18 ·
..... so since I ordered up the syringe, and the oil (which is going to take a while to get here) I decided to take the forks off the bike and disassemble them in preparation. got the legs off, and the cap loose from the tube, managed to figure out how to take the cap off the metering rod...... I'm stuck at taking the inner guide off. The shop manual calls for a specific 27mm tool to take it out of the fork leg. 57001-1744 - ROD GUIDE CASE WRENCH is the item description. Prices for this thing are stupid high, IMHO.

What can be used as an alternate?
 
#20 ·
Thanks! Which do you have?

By the time I am done collecting the tools and the parts this will end up costing what it would for someone else to do the job for me.... Hopefully the tools will carry over to other models.
 
#23 ·
Now that I have my Racetech tool to remove the inner sleeve, I could drain the old fork oil. Still waiting on the new oil and the syringe gizmo to set the correct level with the fresh oil. Not in a hurry to leave the set up open and 'dry', so I will wait for the oil etc., which is supposed to arrive Thursday. So what, if I've already missed the first 70+ degree riding day.

My question at this point is should I use anything other than new, fresh oil to clean out whatever contaminants might be in the old fork oil? What I see when I slide the legs up and down with the cap off looks pretty clean..... I imagine gravity collects the worst at the bottom with no way out. Is there a recommended solvent that won't attack the seals? Mineral oil? Kerosene?
 
#33 ·
Just a quick update.... managed to swap out all of the fork oil with just one liter of oil, with some left over that's in line with what the manual said there should be, so I'm pretty happy at the moment. Of course it all comes down to whether there is an improvement in ride quality.

Didn't take any pictures, as I was fairly well covered in oil by the time I was done. First leg took maybe an hour to work my way through..... some counter intuitive steps in there. Second leg went much quicker, although considerably messier as I thought that I had it down pat, at that point.

Next time, it will be much less painful.

I did wipe down all of the internal components to remove the IMHO small amount of off color stuff on the surfaces. Almost a sooty color. looks better without that.

Put the legs back in the triple clamps, and called it a night.

Tomorrow I will reinstall the wheel, brakes, fender, front fairing.... Good time to clean a lot of the nooks and crannies I ignore between services.
 
#34 ·
Well...... One side is leaking significantly worse than the other, both are leaking more than I can accept. Time to park it until I have the seals and tools in hand to do this again. Hopefully I will be in good enough health to continue this.

I topped the tank all the way to the brim on the way home.... Put it in the garage, and called it a day.

We discuss test results, and treatment tomorrow afternoon.... Not looking forward to that.
 
#35 ·
So the parts are on the way, except for the oil, a deal driver, and whatever will be needed to remove the retaining clip under the dust seal.

I've already ordered the dust seals, so I don't have to worry about preserving them.... One way or another, they will be removed when the time comes.

Do I need circlip pliers? Presuming inner, rather than outer? How deep do they need to reach?
 
#42 ·
Maybe if you've got Parkinson's lol. Don't drink a gallon of coffee beforehand and you won't scratch the chrome :p
 
#44 ·
My question has mainly been answered, it's more a detail issue for me. I presume the retaining clip is carried in a groove in the larger outer tube. I wanted to make sure if I needed circlip pliers to remove it, that they spread that clip in the right direction. It's either got to be forced to expand, or contract to come out of the groove.

I believe the intended use of the imaged plier is to expand the clip?
 
#43 ·
After you've done this job yourself the first time you'll never take it anywhere to have it done. So do yourself a favor and get one of these.

Exactly the same design as other bigger brands but made in the USA by a small shop. Worth every penny.

https://calkinsspeedshop.com/product/forkspringcompressor/
 
#53 ·
So, I decided to go ahead and purchase the motion pro seal driver, and then decided I should probably have the bullet as well, and then decided I might need the grease to ensure the seals and bushings don't get hung up...... and the replacement oil. I'll wait to do the work until all of that arrives. Should be by Tuesday. Amazon Prime.
 
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