Cummins/Onan — Water Pump - Replacement
Repair & overhaul · Cooling system
From a Cummins/Onan owner's manual covering: GTA8.3, GTA8.3 CD1, GTAR 3. Check it applies to your exact model before use.
Applies to: Cummins/Onan GTA8.3 engine
Before you start
- The system must be filled slowly to prevent air locks. During filling, air must be vented from the engine coolant passages.
Procedure
- Drain the coolant.
- Remove the drive belt.
- Remove the water pump.
- Clean the sealing surfaces on the cylinder block.
- Install a new o-ring into the groove in the water pump.
- Install the water pump; torque 24 N.m [18 ft-lb].
- Lift the tensioner arm and pulley to install the drive belt.
- Fill the cooling system with a mixture of 50% water and 50% ethylene-glycol type antifreeze; coolant capacity (engine only) 10.9 liters [11.5 U.S. Qts.].
Tools required
- 10 mm wrench Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Water pump torque 24 N.m [18 ft-lb]
- Coolant capacity (engine only) 10.9 liters [11.5 U.S. Qts.]
- Maximum fill rate 18.9 liters/min [5 U.S. Gal./min.]
Source: Cummins/Onan owner's manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.