2003 Ski-Doo ZX Series Factory Shop Manual, Page 168Get this manual
Subsection 08
Section 04 ENGINE (LIQUID COOLING SYSTEM)
COOLING SYSTEM LEAK TEST
Install special radiator cap (PN 529 021 400) included in engine leak tester kit (PN 861 749 100) on coolant tankInstall hose pincher (PN 295 000 076) on overflow hoseUsing pump also included in kit pressurize all system through coolant reservoir to 100 kPa (15 PSI)Check all hoses and cylinderbase for coolant leaksSpray soapwater solution and look for air bubbles
1, Pressure Cap
Check if the cap pressurizes the systemIf not, install new 90 kPa (13 PSI) cap (do not exceed this pressure)
6,7, Radiator and Radiator Protector
Insert radiator protector into radiator C-rail and crimp C-rail at rear endRefer to FRAME for radiator removal
5, Thermostat
To check thermostat, put in water and heat waterThermostat should start to open when water temperature reaches the following degreeIt will be almost fully open at 50C (122F)ENGINE All TEMPERATURE 42C (108F)