TOPIC:

Hello all, It is getting time for me to order my front fork seals as I have oil drops trickling down onto my front break discs.

I am very confident I can do the repairs myself with some internet investigation and knowledge from my "data" banks ( manuals on cd that came with the bike )

I really want to know If I will need any special tools to do the job, I believe I have read that a "Seal Puller" is needed but is that really something I should spend money on for a one time deal ?

I dont have a lot of money, I have tools at hand and most importantly I would like to know of peoples first hand experience changing the front fork seals, I read that they are under a great deal of tension via the springs, and that they fly out.

Please tell me what comes to your mind. I would appreciate it. once again its a 1978 Kawasaki kz650 c2 model.

The first problem is removing the bottom allen bolt so the forks can be disassembled. For the most part you need an air or electric impact driver to accomplish this. Second problem is lots of corrosion is no doubt on top of the seal making the upper washer and circlip a rusty mess to remove. Third, you need a seal puller to pry the seal out. You may get it out with a screwdriver ect, but a cheap chinese seal puller is recommended. Not a hard job, but some tools are needed to do it. You won't do it without an impact driver.
I guess a quick step by step would be:
1. Loosen top caps, but don't remove them.
2. Remove forks
3. Remove drain philips screws and drain oil, then reinstall screws
4. Use an impact driver to remove bottom allen bolts.
5. Remove top cap, remove spacers, spring ect.
6. Remove dust covers.
7. Remove retaining ring and washer from above seal.
8. Pry out seal with a seal tool.
9. Clean area and tap in new seal with a seal driver or appropriate size socket ect.
10. Reinstall washer and clip.
11. Slide the tubes together.
12. Install bottom allen bolt with an impact driver.
13. Install springs and spacers.
14. Add oil.
15. Reinstall dust covers
16. Compress spring as you attempt to thread on the top cap. This can be a little trying.
17. Reinstall on motorcycle and fully tighten top cap.

Thank you very much for the detailed information. I infact do have all the necessary equipment although I do not have a puller as mentioned. Looks like this job just got a little easier

BECAUSE knowledge is power

Depending on the style of damper rod (I assume round), you'll need some way to hold it should the old Lok-Tite keep the bottom allen bolt from backing out. I've not done a C model, but my B model has a round hole in the top of the damper rod. Kawasaki sold a special tool that looks like a reamer with a round shaft milled to a tapered point with four flat sides. This was jammed into the top of the damper rod (after the spring was removed) to hold it while backing out the bottom bolt.

I made my own version out of a piece of scrap shaft from the farm by grinding one end to a taper with four flat sides and welded a nut to the other end. I stuck the tapered end down into the fork tube so it engaged the damper rod, turned the business upside down and gave it all a firm tap on the floor. With a box end wrench on the nut I was able to easily remove the bottom bolt. I used the same procedure on installation to torque the bottom bolt.

When using the seal puller, use a small piece of wood under it or you'll damage the top of the fork tube as you're trying to pry the seal out. That's a good idea anyway as the seal puller is typically a thin piece of steel that will damage a milled edge with the force applied to remove a seal.

Look at my pages as I documented rebuilding my SR fork seals several years ago . They were a bit different as they have a twelve point head at the top of the damper rod that the right sized bolt head fits into.

The end of the factory tool looks like a pyramid.
Some folks have had luck using a hardwood dowel (old rake handle) carved into the shape of a wedge, then jamming it in. To drain the forks you could remove the top caps & dump it out. After draining them, for a less messy job pour in some solvent, invert, then dump it. Here's a photo of a 650 damper rod (70's model)... I can't seem to find the how-to w other pics...

Here's the pic....
note: the head on some of them looks like a 12-pt 19mm socket.

.

My c3 has has the same end and I made the tool required to hold it . I made a tapered metal one which had 4 faces and should work better than a wooden one . It may work with just an allen key to remove the bolt . I had my bolt removed at my local garage with an impact gun which worked 100% in a few seconds . This method might work with just a wooden holder . Heres a pic of the tool.

Cheers

c3

Before trying to loosen the fork tube caps you should loosen the top triple tree clamp bolts. Otherwise the pressure clamps makes it really hard to loosen the caps.

Also, here's a link to another homemade fork cylinder tool (the tool worked for me).
tool

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JMKZHI wrote:

...Some folks have had luck using a hardwood dowel (old rake handle) carved into the shape of a wedge, then jamming it in...

This works fairly well. If the internals were the same on all of KZ's it wouldn't be so bad, but you need 4-5 different tools if you are working on all the KZ's.

An air impact helps greatly with the allen bolt. I've struggled with some forks doing it by hand.

If you do buy a seal remover, I use a hard plastic strip to lever against to avoid damaging the aluminum of the fork lower with the puller. Even something like a paint stir stick works.

Of course if you have an impact driver you don't need a holder tool. That's why I said earlier to leave the top cap on as you use your impact driver as spring pressure aids in keeping the internals from spinning. Also use dedicated impact allen tools, not cheaper standard ones or you may round out the head of the allen before it comes loose. One last bit of advice, they didn't use loctite of any kind on the bolts and by all means follow suit and don't add any.

RonKZ650 wrote:

Of course if you have an impact driver you don't need a holder tool..

Most times this is true... but not always. I've had a couple that the air impact didn't undo - just spun them around.

RonKZ650 wrote:

One last bit of advice, they didn't use loctite of any kind on the bolts and by all means follow suit and don't add any.

Ron, on my Z1's I will ALWAYS use loctite. I can't speak for all models, but you don't ever want those bolts to come loose.