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The VIAIR 450P-RV EF is a 12-volt portable compressor kit designed for RV tires, including dually setups. Its strongest practical advantages are a 100-percent duty cycle at 100 PSI, long hose reach and chucks intended to reach difficult valve stems.
Official specifications
- Part number 45157.
- 12-volt motor with a maximum 23-amp draw.
- 100-percent duty cycle at 100 PSI.
- Maximum working pressure of 150 PSI.
- Approximately 45 feet of total hose reach plus a 40-inch twist-on chuck.
- IP54 ingress-protection rating.
- About 13 pounds, with a rugged carry bag.
- SAE quick-connect power lead with 40-amp inline fuse holder.
Match part number 45157 and verify the included hoses, chucks, power lead and current specifications.
Why reach matters
A compressor that cannot reach the inside dual or the trailer’s far axle is not useful roadside. Measure from the intended battery connection to every valve stem along a safe routing path. The supplied 45-degree and 90-degree chucks help with dually access, but valve-stem orientation still varies.
Use the correct pressure target
Check pressure when tires are cold and use the vehicle or trailer manufacturer’s specified pressure and load information. The maximum pressure molded on a tire sidewall is not automatically the correct operating pressure for the loaded RV. For motorhomes and trailers, scale weights and tire-maker load tables can be important.
Safe inflation routine
- Park away from traffic, set the brake and stabilize the vehicle.
- Inspect the tire and wheel. Do not inflate visibly damaged, overheated or separating tires.
- Connect the fused battery clamps with the vehicle and compressor switched off, following polarity instructions.
- Route cords and hoses away from hot exhaust, belts, fans and sharp edges.
- Inflate in short checks to the correct cold pressure; never exceed the lowest rated component.
- Allow hot compressor components to cool before packing the kit.
The automatic trigger lets the unit stop compressing when the inflation gun is released, which simplifies moving between tires and checking pressure. “Automatic” does not mean unattended—stay with the compressor and monitor the gauge, hose and electrical connection.
Our buying take
The 450P-RV EF suits larger rigs, higher-pressure tires and owners who want a complete long-reach kit. Smaller RVs may be served by a lighter VIAIR model. Choose by tire size, target pressure, fill-rate expectations and electrical access rather than by the largest PSI number.