For chip detectors, first disconnect the electrical connector.
Removal of two-piece chip detectors. Disconnect electrical connector from the detector. Press
removable center insert in, turn counterclockwise and remove from the valve body. To remove valve body when
necessary, cut lockwire and unscrew, draining the oil.
Inspection. When removing plug or detector, care must be taken not to contaminate the magnetic
gap. Visually check the gap for metal accumulation. The metal deposits may be chips, flakes, and splinters, or in a
granular form. Presence of metal may indicate need for further investigation and corrective action; refer to applicable
Drycleaning solvent is flammable and solvent vapors are toxic. Use P-D-680 Type II Solvent in
a well-ventilated area. Keep away from open flames. Avoid prolonged solvent contact with
Cleaning. Clean magnetic plug or chip detector with drycleaning solvent P-D-680, Type I, or as specified in the
aircraft maintenance manual. Then wipe with a clean lint-free cloth.
Test. Prior to testing, visually check plug body for worn, stripped or damaged threads, and bayonet features as
applicable. Replace as required. If leakage was observed prior to removal of the center insert of a chip detector of this
type, or the still installed valve body leaks, replace with new seals or chip detector as necessary. Inspect plug or detector
magnet and gap. If deformed, or magnet is chipped or cracked, replace with a new unit. Test procedures are provided in
the following paragraphs.
Magnetic ability test. Use a standard steel paper clip, or equivalent, placed across the magnetic gap.
If test piece is held in place, the plug or detector is satisfactory for use. If the test piece is not held in place, replace plug
or detector with a new one.
Make certain that test piece is not magnetized.
Electrical test. This test is to check chip detectors and aircraft wiring. Test procedures are as follows:
Connect detector to aircraft wiring.
Ground body of detector to aircraft.
Warning light should not illuminate. If light comes on, break ground between body and
aircraft. If light continues to burn, wiring is faulty. If light goes out, replace chip detector.
If warning light does not come on, then temporarily place test piece across magnetic gap.
The light should come on. If light does not come on, recheck bridging connection and ground connection. If light still
does not come on check circuit wiring and components, including the light.
Installation for magnetic plugs and chip detectors without center insert. Replace seal if damaged or
deteriorated, screw plug in and torque as specified in the applicable maintenance manual and then lockwire. For chip
detector, connect electrical lead.
Installation for chip detectors with removable center insert. Replace seals it damaged or deteriorated.
Position insert in plug, plug in, and turn clockwise to lock in place. Attach or check electrical connection. Refer to
applicable maintenance manual.
Oil Coolers. Oil cooler types and general maintenance procedures are explained in the following paragraphs.
Reciprocating engine oil coolers. This oil cooler, as shown in figure 3-10, is either cylindrical or elliptical in
shape. It usually consists of a core enclosed in a double-walled shell. The core is built of copper or aluminum tubes.
Cooling air passes through the tubes while the oil flows around the outside of the tubes. This cools the oil for return to
the engine. A bypass route is followed by the oil when the core is blocked or oil is cold.