The Melling Performance Engine Oil Pressure Relief Valve Spring (MPN 55070) is the calibrated coil spring that sets the relief point inside your oil pump. It holds the pump's pressure relief valve seated until oil pressure climbs high enough to overcome the spring's tension, at which point the valve cracks open and bleeds off the excess so the system stays within its target range. This is a Performance-grade spring rated at 70 PSI.
Note: This is the relief valve spring only; mounting hardware and pump components are not included. The spring measures about 5.0 in long, 3.0 in wide, and 0.5 in tall as packaged, and is made in the United States. It installs inside the oil pump's relief valve bore.
Signs this part may need replacing include erratic or low oil pressure readings, a relief valve that no longer holds its setpoint, or a tired spring found during an oil pump rebuild. These symptoms can have other causes, such as a worn pump, clogged pickup, or sensor fault, so diagnosis is wise; if a weak or collapsed relief valve spring is the cause, this replaces it.
Fits: 1957-2003 Buick, Cadillac, Chevrolet, GMC, and Pontiac applications across 262, 267, 283, 302, 305, 307, 327, 350, and 400 engines. See the Buyer's Guide tab for the full list.
Replaces / cross-references: Melling Performance manufacturer part number 55070, sold as Part Eazy SKU P1296MS-55070.
Will it fit my vehicle?
It is listed for 1957-2003 Buick, Cadillac, Chevrolet, GMC, and Pontiac models with 262, 267, 283, 302, 305, 307, 327, 350, or 400 engines. Check the Buyer's Guide tab to confirm your application.
What does it replace?
It replaces Melling Performance manufacturer part number 55070, the oil pump pressure relief valve spring. It is offered as Part Eazy SKU P1296MS-55070.
How do I know it's failing?
Erratic or low oil pressure, or a relief valve that won't hold its setpoint, can point to a tired spring. Other causes are possible, like a worn pump or clogged pickup, so diagnose before replacing.
Is it direct-fit?
It is a direct-replacement relief valve spring for the listed Melling oil pump applications and installs in the pump's relief valve bore. Mounting hardware is not included.
How does it work?
The spring holds the oil pump's relief valve closed until oil pressure overcomes its tension. The valve then opens to vent excess oil, so the spring rate sets the relief pressure point.
WARNING: These products can expose you to chemicals including lead and phthalates, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.
