1999 Volvo Penta "WT" Models Workshop Manual, Page 338Get this manual
Cooling System Components Hoses, Clamps, and Drain Plugs
For all modelsNo special tools requiredInspection Procedure: Examine all external cooling system components for leaks, wear, deterioration, and damageCheck all connections for tightnessInspect hoses for cracks, checking or deteriorationRepair Procedure: Repair or replace as required
Water supply hoses used for replacement must conform to S.A.E20R3, class D-2
Thermostat
All Models Except 7.4 Gi, GSi and 8.2 GSi: 160 (71 C) thermostat is standardF
7.4 Gi, GSi and 8.2 GSi Models: 140
F {64 C} thermo-
stat is standardInspection Procedure: Check for proper rating and style, corrosion, restricted movement, or broken spring