Checking Depth Control Hydraulic System—Drawn

The purpose of this procedure is to determine if total hydraulic depth control system is functioning properly. Based on results found at conclusion of this test, it may be necessary to perform other diagnostic procedures in order to identify specific area which is malfunctioning.

1. CAUTION: Escaping fluid under pressure can penetrate skin causing serious injury. Avoid hazard by relieving pressure before disconnecting hydraulic or other lines. Tighten all connections before applying pressure. Search for leaks with a piece of cardboard. Protect hands and body from high pressure fluids.

   If an accident occurs, see a doctor immediately. Any fluid injected in skin must be surgically removed within a few hours or gangrene may result. Doctors unfamiliar with this type of injury should reference a knowledgeable medical source. Such information is available from Deere & Company Medical Department in Moline, Illinois, U.S.A.

   IMPORTANT: Warm hydraulic oil to normal operating temperature before performing system check.

   With machine unfolded, check all hoses, hydraulic fittings, and cylinder rod seals for external leaks. Repair all external leaks before continuing procedure.

2. Cycle machine up and down three times.

3. Fully raise machine and unfold wings.

4. IMPORTANT: SCV I lever must be placed in NEUTRAL position.

   Position tractor controls in NEUTRAL position. Disconnect depth control hoses from tractor.

5. Measure and record rod length of depth control cylinders.

6. Allow machine to sit idle for 30 minutes.

7. Re-measure and record rod length on depth control cylinders.

8. Compare your results below:

   1. If no cylinders have retracted or extended more than 6 mm (1/4-in.), hydraulic system is operating correctly.

   2. If any uneven retraction, more than 6 mm (1/4-in.), is measured between cylinders, or if any cylinder(s) extended more than 6 mm (1/4-in.), see your John Deere dealer.

9. Reattach hoses to tractor SCV I. With machine unfolded and cylinder depth stops added to each cylinder, place SCV I in CONTINUOUS and completely retract all cylinders.

10. NOTE: Observe that all cylinders are retracted solid against cylinder depth stops.

    Place SCV I lever in NEUTRAL position, and again check that cylinders retract solid against cylinder depth stops. If more than 3 mm (1/8 in.) gap exists on any cylinder, see your John Deere dealer.