Onan 502-0080 Water Pump Square Head Plug
The Onan 502-0080 Water Pump Square Head Plug seals an unused or service port in the Onan pump housing. Small as it is, it is a pressure boundary part, and a weeping plug puts salt water where it should not be and starts corrosion on the housing.
Look for a salt trail around the plug and for corrosion in the drive socket. If it did not come out cleanly, fit a new one on reassembly with fresh thread sealant, and clean the threads in the housing before it goes back. 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. Two are fitted per pump.
Key Features
- Correct thread form and head style for the Onan pump housing
- Seals the port against pump pressure and salt water
- Drive socket in good condition for easy removal at next service
- Direct replacement for a corroded or rounded original
- Inexpensive part to renew during any pump rebuild
Applications
- Raw water pump overhaul on Onan marine generator sets
- Blanking unused or service ports on the pump housing
- Replacing a weeping or corroded original plug
- Building a spares kit for seasonal pump service
Specifications
- Brand: Onan
- Manufacturer Part Number: 502-0080
- Part Type: Square Head Plug
- 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: 2
- Condition: New
- Shipping Weight: 1 lb
Frequently Asked Questions
Q: Can I use a hardware store plug?
Thread form and length have to match. A plug that is too long can protrude into the pump bore and foul the internals.
Q: How many are fitted?
It depends on the pump and the installation. Count what comes out of your pump before ordering.
Q: Should I replace it every service?
Not every service, but replace any plug that did not come out cleanly or that shows corrosion in the drive.
Q: Does the plug need thread sealant?
Yes, fit it with a suitable marine thread sealant unless your Onan service literature specifies a sealing washer instead.
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 square head plug.
CLRMarine
