The Fuel Feed Hand Pump Repair Kit with part number BM1104-G001-01 is a verified direct-fit replacement for ISUZU diesel engines. This hand pump repair kit restores the function of the manual priming pump mounted on the fuel injection pump, allowing operators to manually prime the fuel system and remove air after fuel filter replacement or fuel system service.

The hand priming pump (also called feed pump or primer pump) is a manually operated piston pump mounted on the side of the diesel fuel injection pump. Its purpose is to draw diesel fuel from the tank and fill the fuel filter and injection pump with fuel while bleeding air from the system. The pump consists of a piston, return spring, one-way valves, and sealing elements. Over time, the return spring can weaken or break, and the seals can harden or leak, causing the pump to lose its priming capability.

• Hand pump will not build pressure when pumped — a broken or weakened return spring prevents the piston from returning, eliminating pump action.
• Hand pump operates but fuel does not flow — worn seals allow fuel to bypass internally, preventing fuel from being drawn from the tank.
• Fuel leakage around the hand pump — deteriorated seals allow diesel to seep from the pump body.
• Hard starting after fuel filter replacement — the hand pump cannot prime the fuel system, leaving air in the lines and preventing engine start.
• Pump handle stuck in the down position — a broken return spring prevents the handle from returning to the rest position.
• Air bubbles in the fuel system after priming — worn seals allow air to enter the fuel system during priming.

1. Preparation: Clean the hand pump and surrounding area thoroughly. Place a drain pan under the pump to catch any fuel spillage.
2. Disassembly: Remove the hand pump handle and the pump cover. Remove the old spring, piston, and seals. Clean all components with clean diesel fuel.
3. Inspection: Inspect the pump cylinder bore for scoring or wear. Inspect the piston for wear. If the bore or piston is worn, replace the complete hand pump assembly instead of the repair kit.
4. Installation: Install the new spring, seals, and wear components in the reverse order of disassembly. Lubricate the seals with clean diesel fuel before installation.
5. Assembly: Reassemble the hand pump. Tighten the pump cover to specification.
6. Testing: Operate the hand pump several times to verify it builds pressure and returns properly. Check for fuel leaks at the pump body.
7. Bleeding: Bleed the fuel system thoroughly to remove all air.
8. Final Check: Start the engine and verify proper operation.

• Every 10,000 km: Inspect hand pump for fuel leakage and proper operation. Check for air in the fuel system.
• Every 40,000–50,000 km: Test hand pump priming function. Replace the repair kit if the pump fails to build pressure.
• When fuel filter is replaced: Operate the hand pump to prime the fuel system. If the pump does not build pressure, replace the repair kit.
• When hard starting occurs after fuel system service: Inspect the hand pump and replace the repair kit if worn.

• Standard Packaging: Sealed bag + moisture barrier + neutral carton.
• Custom Packaging: Neutral box, color box, or customer-branded packaging.
• Suitable For: Diesel fuel system repair shops, ISUZU parts distributors, fleet maintenance centers, construction equipment repair shops.
• Supply Capacity: Stable batch supply with batch-level quality reports available.
• MOQ: No minimum quantity requirement