John Deere Mikanix

317/320 Skid Steer Low Oil Pressure

Complaint or Symptom :

4024 / 5030 Engine has low or no oil pressure.

Problem or Situation :

Machine or engine is observed to have low or no oil pressure. When engine is warm, oil pressure in the main galley should be at minimum 15 PSI at Low Idle and around 50 (+ 15) PSI at Rated Speed, Full Load. Check oil pressure by removing a small pipe plug on left side of engine and insert pressure gauge.

When the engine is cold, oil pressure in the cold start galley should be at minimum 35 PSI at Low Idle and at least 65 PSI at High Idle. Check oil pressure by removing a small pipe plug on right side of engine and insert pressure gauge.

Solution :

1. Check engine oil level with the machine on a level surface. If low add appropriate amount of oil to bring level up to recommended level.
2. Remove front governor access cover. Use a mirror to inspect fuel rack retaining plate for the hardened roll pin.
 
 Also, note the amount of vertical movement at the front of the rack. If pin is in the plate, rack may have 0.5 millimeters vertical travel; if pin is missing, rack may have up to 2 millimeters vertical travel. If pin is missing

 remove timing gear cover and inspect oil pump for damage from the roll pin. Cases have been reported in the field where the hardened roll pin falls out, gets sucked into the oil pump, and damages the oil pump. If oil pump checks out OK, replace fuel rack per CTM301 (Which is a very lengthy and delicate process that should only be done in a certified John Deere Shop) and MAKE SURE the pin is located before engine re-assembly (or catastrophic failure could occur).
3. With timing gear cover off remove oil pressure regulating valve (PRV).
 
Is the PRV spring broken? If yes, replace PRV per CTM301. Make sure to use JDG1721-1 when installing PRV plug as this tool stakes the bore to ensure proper plug installation.
4. Inspect oil galleys for missing or improperly installed plugs. Check pipe plugs on both sides of the engine (see pics above for right and left) and galley plugs on both ends of the engine


 If any plugs are missing or damaged proceed with repair.

Photos and Information Courtesy of John Deere DTAC Solutions