1999 Ski-Doo Factory Shop Manual Volume Three, Page 134Get this manual
Section 04 ENGINE Subsection 06 (LIQUID COOLING SYSTEM)
2, Coolant Tank
The coolant expands as the temperature (up to 90-100C (195-212F)) and pressure rise in the systemWhen the limiting system working pressure (cap) is reached (90 kPa (13 PSI)), the pressure relief valve in the pressure cap is lifted from its seat and allows coolant to flow through the overflow hose
COOLING SYSTEM LEAK TEST
Install special plug (radiator cap) (PN 529 021 400) and hose pincher (PN 529 009 900) on overflow hosePressurize all system through coolant reservoir to 100 kPa (15 PSI)Check all hoses and cylinderbase for coolant leaksSpray soapwater solution and look for air bubblesA30C0DA
TYPICAL
When the coolant level is low enough, lift the rear of vehicle to drain the radiators
DISASSEMBLY AND ASSEMBLY
3,4, Sender and Plug
Apply Loctite 592 (PN 413 702 300) thread sealant on sender and plug to avoid leaks
1, Pressure Cap
Check if the cap pressurizes the systemIf not, install new 90 kPa (13 PSI) cap (do not exceed this pressure)