Cooling System - Water Pump Leak Inspection/Diagnostics

T-SB-0117-11

September 1, 2011

Water Pump Inspection and Diagnostic Tips

Service Category
Engine/Hybrid System

Section
Cooling

Market
USA





Applicability

Introduction

This service bulletin contains water pump leak inspection and diagnostic tips.





Warranty Information





Diagnostic Procedure





Water Pump Mechanical Seal

The water pump shaft is sealed by a mechanical type seal.





Temporary Leaks





If debris was trapped between the seal ring and mating ring an abrasion mark may have been left on the mating ring surface. This abrasion mark does not affect sealing performance due to the large sealing surface of the mating ring. Once the debris is no longer present the mechanical seal performance will return to normal operation. Water pump replacement is not necessary.

Inspection method:

NOTE:

Before performing this inspection, confirm that coolant is not leaking from a component other than the water pump. If coolant appears to be leaking from another component, inspect that component following the appropriate repair manual procedure.





1. Visually inspect the water pump and coolant level in the coolant reservoir. Replace the water pump if any of the following conditions exist:

A. The coolant level is below the "low" level and the water pump appears to be leaking.

B. Water pump pulley/bearing has excessive free play or does not turn smoothly.

C. Heavy coolant deposits are present on both the water pump and surrounding components (i.e. pulleys, engine block, timing cover, under hood).





If the above conditions do not apply or amount of deposits are in question, the leak may have been temporary and additional inspection is necessary.





2. A paper towel should be used to determine if a leak is current or was temporary due to debris that has now cleared.





3. Apply a dry paper towel to the coolant deposits around the weep hole. If the paper towel remains dry the leak was temporary and the water pump does not need to be replaced. If the paper towel becomes wet the leak is current and the water pump should be replaced.