Seizure of Thermocouple Threads in Some G3500C and G3500E Exhaust Manifolds{1408, 1900, 7498} Caterpillar

Generator Set:

G3516C (S/N: GSB1-UP; TJB1-UP; TJC1-UP; GZZ1-UP; RWA1-UP; DKR1-UP)

G3516E (S/N: GAS1-UP; SLY1-UP)

G3520C (S/N: MAD1-UP; GZJ1-UP; GZK1-UP; GZL1-UP; GZM1-UP; GZN1-UP; B9P1-UP; RLP1-UP; HAT1-UP; CWW1-UP; CWY1-UP; GHE1-UP; JBX1-UP; JBZ1-UP)

G3520E (S/N: GZG1-UP; GZH1-UP; HAL1-UP; SXY1-UP; GHM1-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

Some thermocouples have seized in some exhaust manifolds. This makes removal of the thermocouples difficult. Sometimes, the thermocouples break during removal. Sometimes, the exhaust manifold is damaged.

Solution

Before you install a thermocouple, lubricate the threads with a nickel based anti-seize compound. The anti-seize compound must also be formulated for use in high temperatures. Examples are listed in Table 1.