2003 Ski-Doo ZX Series Factory Shop Manual, Page 312Get this manual
Section 07 REAR SUSPENSION Subsection 02 (SC-10 SUSPENSION)
gurgling noise, after completing one full compression and extension strokeRenew if any faults are presentAll Models Equipped with Gas Pressurized Shock NOTE: Gas pressurized shocks are painted light gray, purple or bare aluminumGas shock can be inspected as follows: Because of gas pressure, strong resistance is felt when compressing the shockWhen released, the shock will extend unassistedRenew as requiredIf an internal gas leak is suspected, between oil chamber and gas chamber, check shock as follows: Install shock in vise clamping on its bottom eyelet with its rod upwardLet it stand for minutesCompletely push down the shock rod then releaseRod must come out at steady speedIf speed suddenly increases particularly at end of extension, replace shockAll Types of Shock If gas shock is suspected to be frozen, proceed as follows: Place shock in freezer (temperature below 0C (32F)) for hoursPush down rod and note its resistance, compare to new shockIf shock is frozen it will be much more difficult to compress than the new one