whats the trick to changing the water pump belt on the M809?

[Andydieselpower]

Got the radiator out and have all of the belts off with the exception of the water pump belt. I don't see any adjustment to loosen this belt up? I walked the old belt off by using a screwdriver and wrenching the engine over. The new belt is tighter and will not install this way. Do I have to pull the water pump off? The belt system setup on this engine altogether seems kind of clunky for a combat type of repair. The M35 that I had a few years back was 3 times as easy. Let me know whats the trick???

Truck M812 NHC 250 Cummins with 7 belt accesory drive setup.

Thanks,
Andy

 

[papercu]

water

It has been a while since I changed one but you just loosen the pump, it is made to rotate(and not harm the gasket) so that so the belt will come off and back on.
The instruction are found in TM 9-2320 -260-20 Section 3-54 Water Pump Drivebelt Maintenance. Wayne

 

[Andydieselpower]

Thanks Wayne

I thought that might be the case but didn't know for sure. Thanks,
Andy

 

[DaveP]

if you dont want to lose to much coolant you should drain the system down at least below the water pump level before loosening the bolts around the pump. then after loosening the bolts just rotate it like papercu said. it is made off center so as you rotate it the pulley moves closer or further from driven hub. use care as the copper washer (or gasket) behind the pump is hard to locate should you damage it.