Symptoms
Coolant weeping from the pump's tell-tale hole, a wobbling pulley, bearing noise, or creeping temperature under load.
The fix, step by step
- Drain the coolant and remove the belts and fan.
- Unbolt the pump and clean the mating face.
- The Geba replacement for naturally aspirated U1300Ls (OM 353.960/.961/.962/.980) comes with its gasket.
- Refit, tension the belts, refill with the specified antifreeze, and bleed the system before a long run.
- OM 366 engines use a different pump.
Tools & part numbers
- Metric sockets and wrenches
- gasket scraper
- belt tension gauge
Where to buy the parts
Water pump OM352 / U1300L (Geba, new)Expedition Imports ↗Amazon ↗
Water pump, OM366Expedition Imports ↗Amazon ↗
Hunting a used or discontinued part? Search eBay Motors for Mercedes-Benz Unimog U1300L (435) parts →
Rated for a competent home mechanic with a decent tool kit. Confirm torque figures, fluids and procedures against the factory service manual for your VIN, support the truck on stands rather than a jack, and work at your own risk (disclaimer). Some parts links are affiliate links, which pay us a small commission at no cost to you.