5-87610-088-0 8-97105-012-5 Water Pump for Isuzu 4JB1 & 4JG2 Engines

5-87610-088-0 Water Pump for Isuzu 4JB1 4JG2 Engine

The 5-87610-088-0 / 8-97105-012-5 water pump is used for Isuzu 4JB1 and 4JG2 engine cooling system applications. It is also searched as 5876100880, 8971050125, engine water pump, coolant pump assembly or water pump with gasket for Isuzu 4J series diesel engines.

This page focuses on 5-87610-088-0 and 8-97105-012-5 as the main part numbers. Before ordering, the removed pump should be checked by old pump number, gasket shape, pulley area, mounting holes, water inlet outlet position and engine model.

Engine Cooling System Function

The water pump circulates coolant through the engine block, cylinder head, radiator and cooling passages. For Isuzu 4JB1 and 4JG2 engines, a worn or leaking pump can reduce coolant circulation and lead to overheating, coolant loss, belt noise or repeated temperature warnings.

When replacing this pump, the radiator, thermostat, fan belt, hoses, coolant condition and gasket surface should also be checked. A new water pump may still fail to control temperature if the rest of the cooling system is blocked, leaking or poorly maintained.

Application and Model Reference

The main engine references for this product are Isuzu 4JB1 and 4JG2. Bobcat 843 and 853 skid steer loaders are common machine references for this water pump group, depending on engine configuration and previous repair history.

Some public catalogs also list related Isuzu 4J engine references such as 4JA1, 4JG1, 4JH1 or 4JC1. These should be used as checking references only, because different engine versions may use different pump housing, gasket or hose port layouts.

Machine model names should not replace physical confirmation. For final fitment, compare the removed pump, engine nameplate, gasket profile, pulley area and inlet outlet direction before purchase.

Part Number and Reference Notes

• Main part numbers: 5-87610-088-0 and 8-97105-012-5.

• No-hyphen search formats: 5876100880 and 8971050125.

• Main engine references: Isuzu 4JB1 and 4JG2.

• Common model references: Bobcat 843 and Bobcat 853.

• Other catalog references should be verified by old pump and physical configuration before use.

How to Identify the Correct Water Pump

A similar Isuzu 4J series water pump may look close in photos but still use a different gasket shape, impeller housing, pulley area or hose port position. The safest method is to compare the removed pump from multiple angles before ordering.

• Check whether the old pump number matches 5-87610-088-0, 8-97105-012-5, 5876100880 or 8971050125.

• Compare the gasket profile and bolt hole layout.

• Check the pulley mounting area, shaft position and belt alignment area.

• Compare the water inlet and outlet direction with the old pump.

• Confirm the engine model and machine model before shipment.

Common Failure Symptoms

• Engine overheating during operation or after long idle time.

• Coolant leakage near the pump housing, gasket face or drain hole.

• Bearing noise, shaft play or abnormal belt noise around the pump area.

• Coolant loss after replacement caused by uneven mounting surface or gasket issue.

• Poor cooling performance caused by radiator blockage, thermostat failure, fan belt slip or pump impeller wear.

Troubleshooting Before Replacement

Before replacing the water pump, inspect the complete cooling system. Overheating may be caused by the pump itself, but it may also come from coolant blockage, radiator restriction, thermostat failure, fan belt slip, hose leakage or incorrect coolant mixture.

• Inspect coolant level, coolant condition and visible leakage points.

• Check radiator core blockage and radiator cap condition.

• Check thermostat opening and cooling fan operation.

• Inspect belt tension, pulley alignment and bearing noise.

• Check whether the old pump failed because of coolant contamination, rust, dry running or incorrect installation.

Installation and Maintenance Notes

• Drain coolant safely before removing the old pump.

• Clean the mounting surface and remove old gasket material before installation.

• Use the correct gasket and avoid excessive sealant that may enter the cooling passage.

• Tighten mounting bolts evenly according to service procedure.

• Check fan belt condition and pulley alignment during replacement.

• Refill coolant, remove air from the system and check for leakage after startup.

• Monitor operating temperature and recheck coolant level after the first running period.

FAQ

Q: What is 5-87610-088-0?

5-87610-088-0 is an engine water pump reference for Isuzu 4JB1 and 4JG2 cooling system applications. It may also be searched together with 8-97105-012-5, 5876100880 or 8971050125.

Q: Is 8-97105-012-5 the same product group?

8-97105-012-5 is commonly listed together with 5-87610-088-0 in Isuzu water pump references. Final confirmation should still be made by old pump number, gasket shape, housing profile and engine model.

Q: Which engines are common references?

The main engine references for this page are Isuzu 4JB1 and 4JG2. Some catalogs may mention related Isuzu 4J series engines, but configuration should be checked before ordering.

Q: Can this water pump fit Bobcat 843 or 853?

Bobcat 843 and 853 are common model references for this water pump group. Fitment should be verified by engine model, old pump, gasket shape and pump housing before shipment.

Q: What should be checked before ordering?

Check the old pump number, gasket profile, bolt hole layout, pulley area, water inlet outlet direction, engine model and machine model. Clear photos of the removed pump are recommended.