Usage:
3406, 3406B Truck Engines ( 92U, 7FB)
Description of Change: A new water pump group is used on 3406B Truck Engines. The new pump group has three main improvements over the former pump group. The new pump uses a PTFE hydrodynamic oil seal for better oil control. A new double carbon seal (coolant seal) is used that is made of siliconized carbon which is less susceptible to damage caused by solids in the cooling system than the former carbon/ceramic seal combination. The new impeller is made of a fiberglass resin which has better integrity than the former impeller.
Adaptable To: The new 7C4957 Water Pump is a direct replacement for the former 7W7019 Water Pump. The 7C4957 Water Pump Group is in effect with 7FB83348. The new 8C3100 Seal, 7C4958 Seal Group and the 7C5479 Impeller are direct replacements for the former 8T1361 Seal, 4W3864 Seal Group and the 5N7438 Impeller respectively. The new impeller is in effect with 7FB66628. These components can be used as direct replacements for the former seals and impeller in other water pump groups. Refer to Illustration 1 for the location of the new components. A Remanufactured OR2400 Water Pump Group is also available which contains the new components.
Illustration 1. 7C4957 Water Pump.
In order to install the 8C3100 Seal (oil control), mount the seal on the shaft. Then install the shaft and seal into the pump together as a unit. Do not put oil on the new seal at installation, install dry. Use the FT2237 Seal Driver Assembly to install the shaft and seal. Refer to Illustrations 2, 3, 4 and 5 for information on fabricating the FT2237 Seal Driver.
Procedure To Fabricate FT2237 Seal Driver Assembly
1. The seal driver is fabricated from two pieces, the driver itself and the tube. Cut a 101.6 mm (4.00") long piece of 63.5 mm (2.50" dia.) tube as shown in Illustration 2.
Illustration 2. Driver tube.
2. Fabricate the driver from SAE 4140 Steel as shown in Illustration 3.
Illustration 3. Driver.
3. Weld the driver and tube together as shown in Illustration 4.
Illustration 4. FT2237 Seal Driver Assembly.
4. Install the seal on the shaft as shown. The seal must be installed correctly or oil contamination of the cooling system will result. Carefully insert the shaft with the seal installed into the driver as shown in Illustration 5. Install the oil seal dry. Install in the water pump.
Illustration 5. Installation of the seal and shaft with the FT2237 Seal Driver Assembly.