Author Topic: Preload rear adjuster, advice please?  (Read 6004 times)

Offline viper

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Re: Preload rear adjuster, advice please?
« Reply #15 on: January 18, 2014, 08:10:53 am »
OK, Ive solved/fixed the dilema.

I foolishly unscrewed my preload adjuster from the cable that runs to the rear shock. I researched a way of putting it back together as I could not see any point to bleed out air, went on all sorts of forums and even the Concours owners group in the states told me the unit is now toast. Apparently mr kawasaki  makes the shock and the pre load adjuster as a sealed  unit and thats why the whole thing gets replaced when your adjuster knobs siezes. However , as with most things , there is a solution if you look hard enough, I absolutely refused to accept that i was going to trash my rear shock, i even contemplated assembling the whole thing in a bucket of oil.

these are the steps.

using Hydraulic jack oil from halfords

Fill the shock absorber itself with oil, this is only a very small amount . I did use a pair of spring compressors to compress the shock, this  allowed me to pump some air into the adjuster to force open the piston, i filled with oil and released the pressure on the springs, this forced the piston closed and pushed the oil out through the 10mm hole

next you need to fill the adjuster with oil. Back off the adjuster knob to its fully relaxed position. put some oil in through the 10mm hole, only a small amount will go in as the air will trap. Fill the pipe with oil. I did this by attaching a clear tube to the pipe and sucked fluid up through the pipe from a jar containing the fluid, I used a big syringe. Attach the pipe to the adjuster holding the adjuster upside down. Now the fluid will not get into the adjuster without some considerable pressure. With the whole thing still upside down keep forcing the fluid down by using the syringe. keep pulling the syringe back and after about 10 mins of this you will see the air bubbles streaming up the clear tube and you can keep forcing more fluid into the adjuster. you will need to refill the clear tube a few time and use cable ties to make all the connections oil tight.
these next pics explain it better

i left the upside down assembly over night just to make sure all the oil was out.

Now to attach the two parts together , the shock will have oil filled to its brim and the adjuster and pipe will be filled to their brims and still some fluid will be in the clear pipe.
remove clear pipe and the excess oil will spill out and then quickly screw the pipe into the shock its self, for the brief moment you point the pipe down, no oil will actually come out, vacuum forces will hold it in

I cleaned everything up and am pleased to say that they adjuster works so much better than before, on the very first click i now can see the preload starting to operate, before nothing happend for 6 or 7 clicks, the knob felt sloppy and inactive, now its tight from the first turn. The preload can be seen to move out by about 15mm, which is the spec. Ive done a little video of the preload in operation.

video link

Just on a side note , I fitted a neoprene shock tube when i got the bike new and when i took it off for this job the shock was remarkably clean underneath , just a small amount of water staining. No solids or mud or grit at all, i dont have a hugger. Ive refitted the tube with its velcro and top and bottom cable ties. Ive got an even better fit than before as the shock is off the bike

Offline VirginiaJim

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Re: Preload rear adjuster, advice please?
« Reply #16 on: January 18, 2014, 10:24:14 am »
Excellent!  Good work.  Thanks for posting the results.  :goodpost:
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