Excavator:

311D (S/N: CLA1-UP; PNJ1-UP; DWR1-UP; AKW1-UP)

312D (S/N: SKA1-UP; JBC1-UP; FBJ1-UP; RHL1-UP; KES1-UP; HCW1-UP)

312E (S/N: GAC1-UP; MJD1-UP; PZL1-UP; WEY1-UP)

313D (S/N: KXD1-UP; LCE1-UP; LBR1-UP)

314D (S/N: BYJ1-UP; MFK1-UP; TXN1-UP; WLN1-UP; PDP1-UP; XHR1-UP; SSZ1-UP)

315D (S/N: BZN1-UP; CJN1-UP)

316E (S/N: DZW1-UP; YZZ1-UP)

319D (S/N: KRM1-UP)

Introduction

The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use the solution that is identified below.

Problem

The casting on some main control valves are bad due to the malfunction of the casting machine at the supplier. The bad castings can cause the control valves to leak oil.

Solution

The supplier has corrected the issue, however, some defective main control valves have been shipped. Check that the main control valves with the procedure described below.

Illustration 1

Right side view of main control valve

Illustraton 2

1. Inspect the O-ring between the housings on the main control valve for protrusion. If the O-ring is protruding, the valve should be reworked.

   If the O-ring is not protruding, perform Step 2

2. Stall the bucket, boom, or stick for 1 minute. Check for any oil leakage between the housings of the main control valve. If oil leakage is found, the valve should be reworked.

All resource from the website: https://avsmanual.com/i.caterpillar