Kit 72 Repair Kit for HM Unloader Valve – OEM Replacement Part
Part Number: 4080
Category: Pressure Washer Parts → Unloader Valve Repair Kits
Type: General Pump Kit 72 Repair Kit for HM Unloader Valve
The General Pump Kit 72 Repair Kit (Part #4080) is a genuine OEM replacement rebuild kit designed specifically for servicing General Pump HM pressure washer unloader valves. This comprehensive repair kit includes the essential internal wear components required to restore proper pressure regulation, bypass operation, and sealing performance without replacing the complete unloader assembly.
Key Features & Benefits
- Genuine General Pump OEM repair kit
- Designed specifically for HM unloader valves
- Restores proper pressure regulation
- Rebuilds worn internal sealing components
- Improves bypass operation
- Helps eliminate leaks and pressure fluctuations
- Cost-effective alternative to replacing the complete unloader
- Extends unloader service life
- OEM-quality fit and performance
- Ideal for preventative maintenance
Technical Specifications
Part Number: 4080
Manufacturer: General Pump
OEM Kit Number: Kit 72 (ZKHM)
Product Type: Unloader Valve Repair Kit
Compatible Unloader: General Pump HM Unloader Valve
OEM Replacement: Yes
Compatible Unloader Specifications
Designed for servicing the General Pump HM Unloader Valve with the following specifications:
- Maximum Flow Rate: 10.8 GPM
- Maximum Pressure: 3,000 PSI
- Maximum Temperature: 165°F
- Inlet: 3/8" FPT
- Outlet: 3/8" MPT and 1/4" FPT
- Bypass: Dual 3/8" FPT
Kit Contents
The General Pump Kit 72 includes OEM replacement components such as:
- Valve seat
- Valve guide
- O-rings
- Anti-extrusion rings
- Springs
- Washers
- Check balls
These components restore the internal sealing surfaces and pressure-regulating mechanism of the HM unloader.
Why Rebuild Your HM Unloader?
Over time, normal operation causes wear to internal seals, valve seats, springs, and moving components. Rebuilding with Kit 72 helps:
- Restore factory pressure performance
- Improve bypass operation
- Eliminate pressure fluctuations
- Reduce water leaks
- Extend pump and unloader life
- Reduce maintenance costs
Using genuine OEM replacement parts ensures proper fit, material compatibility, and dependable long-term operation.
Common Signs Service Is Needed
Rebuild the HM unloader if you notice:
- Pressure fluctuations
- Water leaking from the unloader
- Reduced cleaning pressure
- Inconsistent bypass operation
- Difficulty maintaining pressure settings
- Delayed trigger response
- Excessive internal wear
Common Applications
Ideal for servicing unloaders used on:
- Commercial pressure washers
- Industrial cleaning systems
- Fleet washing equipment
- Equipment wash stations
- Agricultural cleaning equipment
- Manufacturing facilities
- Contractor-grade pressure washers
- Mobile pressure washing trailers
Performance Benefits After Rebuild
- Restored pressure regulation
- Improved bypass performance
- Better pump protection
- Reduced pressure spikes
- Consistent cleaning performance
- Extended unloader service life
- Lower maintenance costs
- Reduced equipment downtime
Installation Notes
- Shut down the pressure washer and relieve all system pressure.
- Remove the HM unloader from the pump.
- Disassemble the unloader according to the manufacturer's service manual.
- Replace all worn internal components using Kit 72.
- Inspect the valve body and internal surfaces before reassembly.
- Reinstall the unloader and verify proper pressure adjustment.
- Test bypass operation before returning the system to service.
Important: Always use genuine OEM replacement components and follow General Pump service procedures to ensure proper operation and safety.
Maintenance Recommendations
- Inspect the unloader during scheduled maintenance.
- Rebuild the valve when pressure regulation becomes inconsistent.
- Keep inlet water filtration clean.
- Avoid prolonged bypass operation whenever possible.
- Monitor operating pressure regularly.
- Keep a spare Kit 72 available for high-use equipment.
