A steel ribbon-type oil level dipstick may be used to check the level of oil in the engine oil pan. The dipstick is located in a tube attached by a threaded adaptor to an opening in the oil pan. See Figure 21131 .
Oil Dipstick Mounting
Snap action dipsticks have locking tangs and an O-ring seal in the tee handle. A copper sealing ring between the adaptor and dipstick tube insures a tight seal.
Maintain the oil level between the full and low marks on the dipstick. Never allow it to drop below the low mark. No advantage is gained by having the oil level above the full mark. Overfilling may cause the oil to be churned by the balance shafts and crankshaft throws causing foaming or aeration of the oil. Operation below the low mark may expose the pump pickup causing aeration, loss of pressure and engine damage.
Check the oil level after the engine has been stopped for a minimum of ten minutes to permit oil in the various parts of the engine to drain back into the oil pan.
Dipsticks are normally marked for use only when the equipment the engine powers is on a level surface. Improper oil levels can result if the oil level is checked with the equipment on a grade, or if insufficient time is allowed for oil to drain back to the sump. For additional information, consult Service Information Bulletin "Oil Level Gage Calibration Inspection and Fabrication" (SIB 12-50-94).
The current dipstick adaptor has a thicker wall than the former adaptor and requires a copper seal between the adaptor and the nut on the oil gage tube assembly.
To determine if repair is possible or replacement is necessary, perform the following procedure. See Figure 21756 .
Flowchart for Repair or Replacement of Oil Dipstick Assembly
Precleaning is not necessary.
Remove oil dipstick assembly as follows:
Inspect oil dipstick assembly as follows:
Assemble oil dipstick assembly as follows: