Westerbeke BTDA 15.0 Operator's Manual & Installation Manual page 54

Coolant from the engine, when heated during engine operation, will expand, lifting the spring-loaded
manifold pressure cap, and enter the recovery tank by way of the hose connecting the recovery
tank to the manifold.
When the engine is shut down and cools, a small check valve in the pressure cap is opened
by the contraction of the engine coolant, allowing some of the coolant in the recovery tank to
be drawn back into the engine's cooling system, free of air and wtthout loss. Periodically check
that the passage (figure 5.19.4) between the 90" fitting on the mannold and the filler neck in
the manifold is clear so coolant can flow in either direction.
FUNCTION OF MANIFOLD PRESSURE CAP
From Coolant Tank
COOLANT RETRACTION
to Coollnt Tank
figure 5.19.4: Manifold Pressure Cap
Westerbeke Generators
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15.0KWBTDA