Onan 131-0159 Water Pump Cam
The Onan 131-0159 Water Pump Cam is the eccentric insert inside the pump housing that squeezes the impeller vanes down as they sweep past it. That deliberate pinch is what closes each vane pocket and forces the trapped water out of the discharge port instead of letting it carry back round to the inlet. A flexible impeller pump does not work at all without one.
Cams wear at the leading edge and on the face the vanes slide across. A rounded or grooved cam lets water leak back past the vanes, which shows up as poor priming, low flow and a pump that will not lift water after layup. Corrosion under the cam and a loose or backed out cam screw are the other two faults worth looking for once the cover is off. This part is listed for Onan water pumps 131-0165 and 131-0267 on MCCK 4.0 and 6.5 kW, MDJE 7.5 kW and MDJ-A, B and E generator sets.
Key Features
- Eccentric profile machined to the Onan pump housing bore
- Forms the seal between the inlet and discharge sides of the pump
- Compresses the impeller vanes to expel water at the discharge port
- Clamped installation with the original cam screw, no pressing required
- Restores dry priming and rated flow when the old cam edge is worn
Applications
- Raw water pump overhauls on Onan marine generator sets
- Repairing a pump that primes slowly or will not lift water after layup
- Service alongside a new impeller and wearplate
- Correcting impeller vane damage caused by a loose or worn cam
Specifications
- Brand: Onan
- Manufacturer Part Number: 131-0159
- Part Type: Cam
- Fits: Onan water pumps 131-0165 and 131-0267 on MCCK 4.0 and 6.5 kW, MDJE 7.5 kW and MDJ-A, B and E generator sets
- Quantity Per Pump: 1
- Condition: New
- Shipping Weight: 0.1 lb
Frequently Asked Questions
Q: Do I have to replace the cam with every impeller?
No, but inspect it every time. Replace it whenever the impeller has been run dry or has lost a vane.
Q: Will a new cam alone restore flow?
Only if the cam was the fault. Check the wearplate and cover gasket at the same time, since all three share the sealing job.
Q: How do I check the cam for wear?
Look along the edge the vanes climb. A sharp, square edge is good. A rounded edge or a polished step where the vanes cross means it is worn.
Q: Does the cam screw need sealing?
If the screw passes through into the wet side of the housing it does. Use a fresh sealing washer or thread sealant as originally fitted.
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 cam.
CLRMarine
