Sensors & Switches

Oil Filter Differential Pressure Switch Repair & Overhaul

FAA & EASA certified oil filter differential pressure switch repair and overhaul.

About the Oil Filter Differential Pressure Switch

An oil filter differential pressure switch monitors the pressure drop across an engine or system oil filter, providing a warning or bypass indication when the filter becomes clogged with contaminants. It senses the difference between filter inlet and outlet pressure and actuates electrical contacts at a preset differential, alerting the crew or triggering maintenance action before flow is restricted or the bypass opens. Within the sensors and switches architecture it serves as a condition-monitoring device protecting the lubrication system. Repair and overhaul are driven by diaphragm or piston fatigue, calibration drift of the actuation setpoint, spring relaxation, contact wear and pitting, seal leakage between the pressure ports, and contamination that cause inaccurate switching, false indications, or failure to actuate at the specified differential.

Our Oil Filter Differential Pressure Switch Repair Capability

QTC repairs and overhauls oil filter differential pressure switch components to the original manufacturer's specifications under our FAA and EASA Part 145 approvals. Our engineers — including former OEM sensors & switches specialists — perform teardown, inspection, cleaning, component replacement, functional and leak testing, and certification, and develop repairs for rejected and beyond-economic-repair (BER) hardware.

View Differential Pressure Switches capability →

All Oil Filter Differential Pressure Switch Parts We Service

Click a part number for repair details and to request a quote.

Part numberMakeModel
21SN04-383A Pratt & Whitney PW2000/4000
21SN04-391 Pratt & Whitney PW2000/4000
21SN04-391A Pratt & Whitney PW2000/4000
21SN04-404 Pratt & Whitney PW2000/4000
21SN04-405 Pratt & Whitney PW2000/4000
21SN04-416 Pratt & Whitney PW2000/4000
21SN04-417 Pratt & Whitney PW2000/4000

Frequently Asked Questions

Does QTC repair oil filter differential pressure switch components?

Yes. QTC repairs and overhauls oil filter differential pressure switch components under our FAA & EASA Part 145 approvals. Our catalog lists 7 oil filter differential pressure switch part numbers. Request a quote to confirm capability and turnaround.

What aircraft use the oil filter differential pressure switch?

In our catalog, oil filter differential pressure switch part numbers appear on Pratt & Whitney. See the full parts list below.

What is involved in oil filter differential pressure switch repair and overhaul?

Our process typically includes incoming inspection, disassembly, cleaning, non-destructive evaluation, repair or replacement of worn elements, functional/leak testing, and certification with the appropriate airworthiness release.

Request a Quote for Oil Filter Differential Pressure Switch Repair

Send us your part numbers and condition. Our engineers respond with repair scope, turnaround, and pricing.