SUPPLEMENT FOR 768C TRACTOR & 769C TRUCK & 771C QUARRY TRUCK Caterpillar

1. Clean or replace the relief valve if the cooling system overheats or loss of coolant is observed.

2. Stop the engine, and allow the coolant to cool.

3. Slowly loosen the filler cap to release the pressure from the cooling system.

4. Mark the position of cover (1) so it can be installed in the same position.

5. Remove cover (1) and gasket (2).

6. Remove valve (3), plate (4) and gasket.

7. Clean and inspect all parts. Replace damaged parts.

9. Install the pressure relief valve in the reverse order.

10. Fill the cooling system to the correct level. See the Maintenance Guide.