HOSE AS 3705988 - Caterpillar

Marine Engine:
3508B (S/N: S2A1-UP; S2B1-UP; S2D1-UP; S2E1-UP)
3512B (S/N: S2G1-UP; S2H1-UP; S2J1-UP; S2K1-UP; S2L1-UP; S2N1-UP)
3516B (S/N: B5G1-UP; S2P1-UP; S2R1-UP; S2S1-UP; S2T1-UP; S2W1-UP; S2X1-UP; S2Z1-UP)
3508C (S/N: TTA1-UP; TTB1-UP)
3512C (S/N: TTC1-UP; TTE1-UP; TTF1-UP; MRG1-UP; TTG1-UP; MKH1-UP; SLM1-UP)
3516C (S/N: TTD1-UP; PAG1-UP; TTH1-UP; TTJ1-UP; JTS1-UP)
Previously, the 7N-4885 Coolant Level Switch Gp was installed on either the right side or the left side of the expansion tank. Normally, the switch was installed on the serviced side of the engine. If the serviced side was the right side, the switch was mounted on the right side of the expansion tank.Note: If the engine was also equipped with the optional coolant level sensor, the sensor was installed on the right side of the expansion tank and the coolant level switch was installed on the left side.The outlet for coolant flow from the expansion tank to the water pump is at the bottom of the right side of the expansion tank. During engine acceleration, the coolant can be rapidly drawn from the expansion tank. This has sometimes created a venturi inside the coolant level switch's lower tube, which causes the switch to falsely detect a low coolant level. The occasional momentary condition creates a false low coolant level warning. For this reason, the coolant level switch is now only mounted on the left side of the expansion tank.Note: For engines that are equipped with the optional coolant level sensor, the sensor is not susceptible to a venturi.The coolant level switch has been mounted only on the left side of the expansion tank since 14July 2008.