Possible Coolant Leaks in Certain 3500 Cylinder Heads{1100, 1395} Caterpillar

Engine:

3508 (S/N: 68Z1-UP; 69Z1-UP)

3508B (S/N: S2A1-UP; S2B1-UP; S2E1-UP; 5PS1-UP; S2D1-UP; 6PN1-UP)

3508C (S/N: TTB1-UP; LLE1-UP; TTA1-UP; LLC1-UP)

3512 (S/N: 24Z1-UP; 65Z1-UP; 49Y1-UP; 51Y1-UP; 67Z1-UP; PTG1-UP; PTH1-UP)

3512B (S/N: 2AF1-UP; S2G1-UP; S2H1-UP; S2J1-UP; S2L1-UP; 3ZW1-UP; 4AW1-UP; PWG1-UP; 8RM1-UP; PTF1-UP; FFG1-UP)

3512C (S/N: LLA1-UP; TTC1-UP; LLF1-UP; TTF1-UP; MLM1-UP; SLM1-UP; R1A1-UP; MKH1-UP; E3W1-UP)

3516 (S/N: 73Z1-UP; ZAL1-UP; 8TW1-UP)

3516B (S/N: 7RN1-UP; S2P1-UP; S2R1-UP; S2W1-UP; S2X1-UP; S2Z1-UP; BCK1-UP; S2S1-UP; S2T1-UP; PBR1-UP; GZT1-UP)

3516C (S/N: TTD1-UP; PAG1-UP; TTH1-UP; TTJ1-UP; JTS1-UP; PES1-UP; SBK1-UP)

Excavator:

5130B (S/N: 2GR1-UP)

5230B (S/N: 7TR1-UP)

Off-Highway Truck/Tractor:

783B (S/N: 4WJ1-UP)

785D (S/N: MSY1-UP)

789C (S/N: 8WM1-UP; 2BW1-UP)

797 (S/N: 3TN1-UP; 2CS1-UP; 1AW1-UP)

785C (S/N: APX1-UP; 1HW1-UP)

789 (S/N: 54Z1-UP)

793D (S/N: FDB1-UP)

797B (S/N: JSM1-UP)

777D (S/N: 2YW1-UP; AGY1-UP)

784C (S/N: 2PZ1-UP)

777D (S/N: 8BR1-UP)

Generator Set:

3508B (S/N: ZAD1-UP)

3512 (S/N: 1KZ1-UP; FDR1-UP; 6WW1-UP; ZAF1-UP)

3512B (S/N: 1GZ1-UP; ZAH1-UP; ZAJ1-UP; PTM1-UP; 6GW1-UP)

3512C (S/N: SBG1-UP)

3516 (S/N: 1LZ1-UP)

3516B (S/N: ZAP1-UP; 8NW1-UP; FDX1-UP; GZY1-UP; ZAR1-UP)

3516C (S/N: SBJ1-UP)

Power Module:

3516B (S/N: BPD1-UP)

3516C (S/N: MHB1-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.

This issue affects cylinder heads on certain 3500 diesel product built between 15August 2008 and 28October 2008. These cylinder heads have been traced to a specific set of castings which can be identified by three raised dots located near the outboard machined rail of the head. Refer to Illustration 1.

Illustration 1	g01753074
(1) Three raised dots on the casting

Problem

Cylinder head castings that were poured using a certain pattern are susceptible to a water passage core shift. These conditions have resulted in a potential for penetration into the water jacket passage at the following locations:

• Though the drilled left hand side lifting eye hole. This is a 9.53 mm (0.375 inch) hole that is located 38.10 mm (1.50 inch) left of the injector bore.

• Through the right hand side 15.88 mm (0.625 inch) rocker shaft bolt hole on the top deck of the cylinder head.

Refer to Illustration 2.

Illustration 2	g01753094
Top view of the cylinder head Holes to check for coolant leaks (2) Lifting eye hole (3) Rocker shaft bolt hole

Penetration of the water passage by lifting eye hole (2) creates a coolant leak path into the rocker box and a subsequent oil dilution problem. Penetration of the water passage by rocker shaft bolt hole (3) may allow coolant in the engine oil or allow oil into the cooling system.

Solution

The steps below are recommended in addition to standard troubleshooting steps for the following problems on engines within this date range:

• A complaint of coolant in the oil

• SOS sample results with higher than normal levels of Sodium or Potassium

1. Remove the valve covers and look for signs of coolant buildup on the top of the cylinder head.

2. If coolant is observed on any of the cylinder heads, first inspect lifting eye hole (2) .

3. If no leaks are observed, remove the rocker arm shaft. Inspect rocker shaft bolt hole (3) for coolant leaks.

4. If any leaks are observed, remove the cylinder head and replace the cylinder head. Replace the contaminated engine oil.

5. If a leaking cylinder head is found, contact the Dealer Solution Network (DSN) as soon as possible in order to determine if parts need to be sent back to the Lafayette Engine Center.

Note: Pressurizing the cooling system could aid this troubleshooting process.

Note: For engines being worked on with factory fill oil, the oil contains a dye that glows bright green under ultraviolet light. If a flashlight is used to look at the oil, the oil will appear green in color. The green color is similar in appearance to coolant. If coolant is suspected in the oil, sample the oil and test for water.