Servicing your R11XXRT
or K1200LT Rear Shock Preload Adjuster
My riding buddy Roger told me he was
considering a new rear shock on his LT. It seems his preload adjustment
wasn't working like it used to. I brought him to my house and we refilled
his preload circuit in about 15 minutes the other day. Now he has the full
range of preload just like when his bike was new.
The hydraulic preload adjuster on your LT or RT 'can' cause a problem with
ride height. I've found several RT rear shocks that have lost their original
range of adjustment. What happens is the hydraulic jack oil in the preload
circuit seems to evaporate just a little over time. I've refilled 3 of them
and restored the full range of adjustment in each case.
The easiest way to test for this is to back off the adjuster knob till you
feel the resistance go away. That is the point where the hydraulic adjuster
ceases to adjust anything. If the point of no resistance isn't up near the
top (soft) end of the adjustment knob, turn the adjuster FULLY counter
clockwise and remove the adjuster from it's mounting bracket. Unclip the
hose retainers. While holding the adjuster upside down, remove the banjo
fitting at the adjuster and keep the hose end vertical so no oil seeps out.
Ensure the adjuster is Fully counter clockwise all the way and stick a nylon
rod or something similar in the hole where the banjo fitting attaches and
push the piston all the way back. Keep the adjuster upside down during
this entire process.
Next you add jack oil to the adjuster piston
until it runs out. Re-install the banjo fitting (with new crush rings if you
can find them but I've never had one leak) and before you tighten the banjo
fitting, twist the adjuster knob clockwise about a quarter turn to eliminate
any air bubbles.
Check the adjustment range. If you were low on jack oil, it WILL be much
better. This may save some folks the price of a new rear shock. I found
hydraulic jack oil at my local auto parts store years ago for refilling my
floor jacks. This oil is totally separate from the shock absorber function.