The only temporary parts I used in Eight Ball project were Kawasaki Zephyr 750 shocks. Originally they were installed on my friend’s Zephyr. Soon after he bought his bike this shocks started to leak. The reason was point of corrosion on shocks rods and in old seals made in far 1991. Usually rod corrosion means death for shocks. But I found how to fix such issue and how to prolong shocks life at least for another twenty thousand kilometres. I cleaned out corroded points by rotary tool, soldered them, polished the rods, changed seals by new ones and shocks worked well after that. Later we replaced repaired shocks, thus I’ve got this pair of shocks on shelf in my garage.
That was some eight years ago, shocks had high millage as before so after repair. I also hadn’t original shock seals at hand in those far away times so when I decided to use these shocks in “Eight Ball” project I knew that probability of their leakage was quite high. And this Spring such event has finally happened.
The leakage was very small, just oil sweating but I didn’t want to stop riding anyway so I decided to buy another pair of shocks. After some searches I bought a pair of used Zephyr 550 shocks on GB ebay. They were decelerated as “leaking/for repair” parts, but that was ok, I had intention to repack them.
And that was also a good reason to write this article.
As Zephyr 550-750-1100 shocks are typical Kayaba (KYB) dual shock so this tutorial may be useful in case of other Kayaba shocks repacking.
I didn’t shoot photos of shocks before disassembling but that’s how they looked on ebay lot page:
So let us begin the REPAIR.
Firstly we need to remove spring and adjuster. That’s obviously process and my only recommendation is to use cable ties to make it more easy.
Next step is removing the air reservoir cap. If your shocks have no back pressure you may do it later, but it’s highly recommended to be made first for you own safety. Don’t try to remove cap with screw driver, it pressed very tightly and after two decades is very hard to pull it out. So we need to drill two holes in cap and then pass steel wire through them:
Thereafter we may unscrew lower shock head (I prefer this method, but there is another option: after removing rod from cylinder you may unscrew piston nut, previously cut off battered thread on the rod end above nut of course).
Then we shall remove shock cylinder cap. For this purpose there are special holes in Zephyr 550 shock caps. I used broken drill bit to remove caps, but if there are no such holes in your shocks caps, wide chisel will be useful tool.
Our next point is air reservoir removing. This issue as simple as seal head removing, but after years reservoir may seat in its place tightly and you might find it difficult to push with bare hands. I don’t like idea of hammering it out in case of shocks so I used a piece of wood, wrench socket and a vise:
As a matter of fact, if rod has no damages and upper and lower bushing are intact, the further repair may be reduced to mere changing of seal, oil and maybe dust seal.
To remove upper rubber from seal head:
The dimensions of seal are 12.5x27x5. It also could be found on ebay and in shops as KYB 12.5 seal.
Assembling of seal head is invert to disassembling. The rolling may be restored with help of hammer and wrench socket:
To be continued.