Onan 131-BRG Water Pump Bearing
The Onan 131-BRG Water Pump Bearing supports the pump shaft and holds it concentric in the housing so the impeller runs true and the shaft seal stays square to its bore. It carries both the belt or drive load and the hydraulic side load the impeller generates.
Bearings in a raw water pump almost always fail because the shaft seal let salt water in. The grease emulsifies, the races corrode, and the bearing goes rough and then noisy. Replace the shaft seal and the slinger at the same time, or the new bearing will follow the old one. This part is listed for Onan water pump 131-0257 (casting 170-3172) on MCCK 4.0 and 6.5 kW and MDJE 7.5 kW generator sets. Two are fitted per pump, so order in pairs when rebuilding.
Key Features
- Dimensioned to the Onan pump shaft and housing bore
- Carries the radial and thrust loads from the drive and impeller
- Keeps the impeller running true and the shaft seal square
- Direct replacement for the original bearing
- Fitted as part of a normal pump rebuild
Applications
- Raw water pump overhaul on Onan marine generator sets
- Replacing bearings damaged by shaft seal leakage
- Curing pump noise, drag or play at the impeller hub
- Full rebuild alongside the shaft, seal and slinger
Specifications
- Brand: Onan
- Manufacturer Part Number: 131-BRG
- Part Type: Bearing
- Fits: Onan water pump 131-0257 (casting 170-3172) on MCCK 4.0 and 6.5 kW and MDJE 7.5 kW generator sets
- Quantity Per Pump: 2
- Condition: New
- Shipping Weight: 1 lb
Frequently Asked Questions
Q: Why did my pump bearing fail?
Almost always because the shaft seal was passing water. Fix the seal and slinger at the same time or the new bearing will not last.
Q: How do I test a bearing without stripping the pump?
Take the belt off and turn the pump by hand. Roughness, notches or a rumble, or play felt at the impeller hub, means replace it.
Q: Do these need packing with grease?
They are supplied ready to run. Do not wash out or repack them unless your Onan service literature calls for it.
Q: How should it be pressed on?
Press only on the race that is being fitted, never through the balls, and support the shaft or housing properly.
Not sure this is the right part? Send us a Picture of the Pump Plate on your pump and the CLR Marine team will confirm the correct bearing.
CLRMarine
