• Pressure loss
  • Converter drain back


Relief Valve
Part No. 10000-01K

Low radius

Package Quantity: 10

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Sonnax now offers replacements 10000-01K and [10000-02K] for the various relief valves and drainback valves that are found in valve bodies. The design of the OE valves causes the separator plate and valve bore to wear. The result is leakage or valve sticking. The Sonnax valve is rounded so it seals against an unworn part of the separator plate and eliminates sticking problems.

The Sonnax valve is ideally suited for replacing the drainback valve on AXOD, AXOD-E, AX4N and AX4S units. The OE drainback valve frequently sticks in the bore. A common shop practice is to replace the OE drainback valve with a check ball. However, this practice requires shortening the spring. The Sonnax valve solves the sticking problem and is designed to work with the existing spring. No spring modifications are needed.

Although either part number can be used in multiple locations, it is suggested to use a relief with a radius close to original, maintaining the spring rate. On a severely worn plate or bore, the higher radius will allow for better plate contact and less bore hang-up.

  • Works with existing spring
  • No modifications needed
  • Material: Steel

Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.

Ford AX4N/4F50N Valve Body Layout

Ford AX4N/4F50N Valve Body Layout
  • 4F50N, AOD, AX4N, AX4S, AXOD, AXODE Relief Valve 10000-01K