Leaks in raw water systems can cause extensive engine corrosion so they should be cured as soon as possible.
Rubber pipes deteriorate with age and lose both flexibility and elasticity. Temporary repairs to hoses can be carried out with insulation tape and a hose clip.
Heavy duty hose clamps are available in larger sizes and provide an even pressure around the hose. Include in any maintenance programme replacement of hoses and clamps after five or six years.
Most direct-cooled engines have a sacrificial zinc anode to minimise corrosion, fitted somewhere inside the engine block. This should be checked annually and renewed if more than 50% eroded.
