2003 Ski-Doo ZX Series Factory Shop Manual, Page 319Get this manual
Section 07 REAR SUSPENSION Subsection 03 (SC-10 III SUSPENSION)
SHOCK ABSORBER INSPECTION
All Models Equipped with Hydraulic Shock NOTE: Hydraulic shocks are painted black or dark graySecure the shock body end in vise with its rod upwardIf suspecting an internal gas leak 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 shockHPG VR Shock NOTE: Gas pressurized shocks are light gray or purple painted, or bare aluminumGas shock can be inspected as follows: Because of gas pressure, strong resistance is felt when compressing shockWhen released, the shock will extend unassistedThe rod speed coming out will go slowfaster and slow again due to the VR zoneRenew as requiredFor the verification of stroke, install shock in vise keeping the rod upwardVerify the stroke compression when the rod is fully extendedThe feeling will be stiff for around first 25 mm (1 in), soft up to 25 to 50 mm (1 to in) and stiff after thatThis stiff, soft and stiff phenomenon shows the normal operation of shockAll Types of Shock If suspecting frozen shock proceed as follows: Place shock in freezer (temperature below 0C (32F)) for hoursPush down on rod and note its resistanceIf shock is frozen it will be much more difficult to compress than for the new one