Our office will be closed 9/7/2026 in observance of Labor Day. Orders placed during this time will be processed when our office opens 9/8/2026.
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Replaces old part number DS-3903927.
This item is a new replacement part shipped with a 12-month warranty.
O RING
Genuine Cummins Part
$9.79
WASHER
$4.87
RING SEAL
$0.83
PRESSURE REGULATOR PLUNGER - 4B3.9 / 6B5.9 / B5.9 / ISB3.9 / ISB5.9G / QSB3.9
$18.72
