Lafayette 3606 Engine VPB3800 - Caterpillar

Failure to keep the condensate drain valve functional can cause severe damage to the engine.
Illustration 1 g03161198
(1) Valve
(2) Plunger
(3) Valve seat The engine boost pressure forces the plunger to move down to the valve seat. The plunger must close against the seat at a pressure of 2.8 kPa (0.4 psi). The absence of boost pressure when the engine is stopped allows the plunger to rise to the open position. The open position allows condensation from the aftercooler to drain out.The plunger must be able to move freely in order to close the system when the engine is running. The plunger must be able to move freely in order to allow condensation to drain from the aftercooler when the engine is stopped. Residue from normal engine operation could cause the plunger to stick.
Remove the valve from the adapter. Check the valve in order to determine if the plunger moves freely. If the plunger does not move easily, clean the valve with solvent.
Reassemble the aftercooler condensate drain valve. See Specifications Manual, SENR3130, "Torque Specifications" for more information on the proper torques.