1983/01/10 Caterpillar

1693 Truck Engines

The 9L1471 Impeller Assembly is used in the water pump groups on 1693 Truck Engines. This impeller assembly has a ceramic seal which is held in position by adhesive. During engine operation, this ceramic seal can become damaged or worn out.

Formerly, the ceramic seals were not available for parts service. When a replacement of the seal had to be made, it was necessary to make a replacement of the complete impeller assembly.

An 8S7762 Ceramic Seal is available for parts service. This ceramic seal can be fastened to the existing water pump impeller with adhesive. The seal is 1.85 mm (.073") thicker than the seal used at the factory. Because of this, it will be necessary to machine the impeller to a new thickness before the new seal is installed. See Illustration 1.

Illustration 1. New dimensions for impeller.

To make sure the seal is located correctly and that even pressure is put on the seal while the adhesive cures (dries), make a fixture as shown in Illustration 2. The fixture can be made from steel or aluminum.

Illustration 2. Dimensions for fixture.

Use the procedure which follows to install a new ceramic seal on the water pump impeller.

1. Machine the 9L1471 Pump Impeller Assembly to the new dimensions shown in Illustration 1.

2. Make sure the new 8S7762 Ceramic Seal and the impeller assembly are free of oil, antifreeze, solvent, etc. Do not touch the finished side of the seal; fingerprints and/or oil decrease the performance of the seal.

3. Put adhesive on the surface of the impeller and on the side of the seal with round identification marks.

NOTE: Make sure adhesive does not get on the finished side of the seal or the fixture.

4. Put the seal in position on the impeller. Install the fixture into the seal and into the bore of the impeller.

5. Install a 1/2" - 20 NF × 2.75" bolt (part number S1599) and a flat washer through the impeller and into the fixture.

6. Tighten the bolt so that the seal is held against the impeller. Do not damage the seal.

7. Let the adhesive cure before the fixture is removed.

The only two adhesives which are recommended are 5P3321 Adhesive (Epoxy) or Depend #330 Adhesive. The Depend #330 Adhesive is available from:

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