This Racor water-in-fuel sensor for 500MA is a passive 2-wire probe for detecting water in the collection bowl of the Racor 500MA diesel fuel filter. The sensor corresponds to Racor/Parker part number RK21069 and is intended for the filter with item no. 17.667.01.
The sensor is mounted in the sensor port at the bottom of the filter's water and contaminant collection bowl. When the water level reaches the probe's metal tips, an external detection module registers the change in electrical resistance and activates the connected lamp or buzzer, depending on the selected alarm system.
The probe is designed as a single piece with two fixed, molded-in wires. The wire length is 21.6 cm, the sensor tips are made of stainless steel, and the connection thread is 1/2"-20 UNF. The installation uses an SAE J1926 O-ring port.
The sensor contains no internal resistor, amplifier, or complete alarm function. It must be connected to a compatible Racor water detection module for 12 or 24 V DC and must not be connected directly to a voltage source. Documented detection modules include, among others, RK14329 for 12 V, RK14321 for 24 V, and RK20726 for 12/24 V. The module is not included.
When mounting in the 500MA system, the specified tightening torque is 1.7-2.3 Nm. A loose fit or damaged O-ring can cause air intake or fuel leakage around the sensor. When the alarm is activated, the collected water must be drained from the filter bowl as soon as possible. The associated detection system normally resets when the water no longer touches the probe tips, unless the module used functions differently.
Compatibility and part numbers
Documented compatibility: Racor 500MA diesel fuel filter, item no. 17.667.01. The manufacturer part number is RK21069. RK33803 is documented as a redesigned alternative WIF probe, but this item is supplied as the RK21069 version.
Always check the filter model and original part number before purchasing.
Key featuresPassive water-in-fuel sensor for Racor 500MA
Manufacturer part number: RK21069
2 fixed wires
Wire length: 21.6 cm
Thread: 1/2"-20 UNF
Stainless steel sensor tips
Mounts in the filter bowl sensor port
Requires a separate compatible detection module
Tightening torque: 1.7-2.3 Nm
