Water Pump Spanner 41mm 1/2in Drive for Older Opel Vauxhall

A 41mm water pump spanner with 1/2in drive, used on older GM-based engines where the water pump is turned to adjust camshaft belt tension. It suits older Opel and Vauxhall applications and is also used on selected Chevrolet and Daewoo vehicles.

Used for cam belt and timing belt work, this type of spanner helps when servicing engines that rely on water pump movement for belt tension adjustment. It is suited to vehicle maintenance, garage work and repair jobs on older engines in the listed size range, whether you are carrying out routine servicing or replacing timing components.

The 41mm head size matches the specified water pump fitting, while the 1/2in drive allows it to be used with common ratchets or breaker bars already found in many tool kits. It covers older 1.2, 1.3, 1.4, 1.6V, 1.6D and 1.8 engines as listed, giving a straightforward way to make the required adjustment without relying on makeshift methods. For regular timing belt work on these engines, having the correct size tool close to hand helps keep the job controlled and avoids unnecessary slipping during adjustment.

Opel Vauxhall water pump spanner specifications

• Size: 41mm spanner for the specified water pump adjustment fitting.
• Drive: 1/2in drive for use with compatible ratchets and related drive tools.
• Application: Used where the water pump is part of camshaft belt tension adjustment.
• Covers: Older Opel, Vauxhall, Chevrolet and Daewoo vehicle applications.
• Engine use: Listed for 1.2, 1.3, 1.4, 1.6V, 1.6D and 1.8 engines.
• OEM reference numbers: KM421A, J-42492.

A practical choice for timing belt and servicing work on older GM-based engines.