Cooling System - Checking Excessive Coolant Loss: Overview

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SECTION GROUP NO.

26 5

DATE FEBRUARY 1988

RE: WATER PUMP, CHECKING

B230F/FT

700 SERIES


THIS BULLETIN APPLIES TO THE U.S. AND CANADA, AND SUPERSEDES SB 26-5, JULY 1987
REFERENCE: TP 30897/1 (English), Engine B230FT TP 31140/1 (English), Engine B230F TP 31003/1 (English), B200, B230 Engines


WATER PUMP, CHECKING

Water pumps are,sometimes replaced when, for instance, only a gasket is leaking. If excessive coolant loss is suspected, the cooling system should be pressure-tested to determine if the system is leaking and the location of the leak.

NOTE: If it is not verified that the system is losing coolant, a small discoloration around the drain hole for the water pump shaft seal is not evidence of active coolant leakage, and is considered a normal operating condition.

The water pump shaft seals are designed to operate utilizing the coolant as a lubricant. This will create a very small seepage of coolant through the drain hole during engine cooldown. An improved pump seal that will minimize this seepage has been introduced into production starting with coolant pump date code 645.