Installation of 7W1497 or 7W6555 Thermostatic Valve Group{1063, 1355} Caterpillar

Introduction

A thermostatic valve group must be installed into the coolant circuit between the aftercooler and the heat exchanger on G398 and G399 LEE in accordance with their standard rating. This is necessary to ensure that the air-fuel ratio does not change.

On G398 and G399 LEE the coolant temperature to the aftercooler must be controlled as follows:

A. For G398 LEE rated above 465 kW (625 bhp) at 1200 rpm or 440 kW (590 bhp) at 1000 rpm and for G399 LEE rated above 620 kW (830 bhp) at 1200 rpm or 525 kW (700 bhp) at 1000 rpm, the coolant temperature to the aftercooler must be 32° ± 4°C (90° ± 7°F).

B. For G398 LEE and G399 LEE at or below the above ratings, the coolant temperature to the aftercooler must be 54° ± 4°C (130° ± 7°F).

The 7W1497 Thermostatic Valve Group is installed to control the temperature of coolant to the aftercooler at 32° ± 4°C (90° ± 7°F).

The 7W6555 Thermostatic Valve Group is installed to control the temperature of coolant to the aftercooler at 54° ± 4°C (130° ± 7°F).

Installing Thermostatic Valve Group

Install the 7W1497 or 7W6555 Valve Group according to the following schematic.

1. Heat exchanger for aftercooler coolant.

2. Thermostatic Valve

A. Outlet

B. Bypass inlet

C. Normal inlet

3. Auxiliary water pump

4. Aftercooler inlet

5. Aftercoolet outlet