Description
The PAI MHV-4223 is an aftermarket water heater shutoff valve for Cummins 855-series (Small Cam through FFC) and Mack E6 diesel engines. The manual valve sits inline on the cab heater coolant supply, letting drivers stop hot coolant flow during warm months or for heater core service. Direct replacement for Cummins 212042 / 157098, Mack 25MF126 / 25152120, and International 288192 / 288192C91.
Signs You Need a New Heater Shutoff Valve
- Coolant leak at the valve body, stem, or hose connection
- Valve handle stuck or difficult to turn
- Cab heat remains on with the valve in the closed position
- Visible corrosion or weeping at the packing nut
Specifications
| Manufacturer | PAI Industries |
|---|---|
| Part Number | MHV-4223 |
| Part Type | Water Heater Shutoff Valve (manual) |
| Hose Connection | 5/8″ O.D. |
| Pipe Connection | 3/8″ NPT |
| Engine Compatibility | Cummins 855 (Small Cam, NTC, FFC, NT855, NTA855); Mack E6 |
| Country of Origin | United States |
| Warranty | 2-Year Unlimited Mileage (Genuine PAI) |
Cross References
This valve replaces or is equivalent to the following part numbers:
- Cummins: 212042, 157098
- Mack: 25MF126, 25152120, 4333-288192C91, 6635-V404P106
- International: 288192, 288192C91, 301803, 301803R91
- PAI: MHV-4223, 4223
Applications
This heater shutoff valve fits the following engines:
- Cummins 855 Small Cam, Big Cam I/II/III/IV, NT855, NTA855, NTC855, FFC (1968–1999)
- Mack E6 mechanical (E6-237 through E6-350) (1968–1992)
Representative trucks using these engines:
- Mack R-Model, RD, DM, CH, CL series (with E6 power)
- Kenworth W900A/W900B, Peterbilt 359/379, Freightliner FLC/FLD, International Transtar/9300 (with Cummins 855)
Verify your existing valve’s port size and orientation before ordering. Install with appropriate hose clamps and use thread sealant on the 3/8″ NPT pipe end.
