VALVE GP-CONTROL 1248820 - Caterpillar

3204 And 3208 EnginesReference: Service Magazine, May 17, 1982. The article "Holes Added To Water Pump Impeller" tells how to add two vent holes to the impeller. The FT1783 Drill Fixture will make it easier to drill the vent holes in the water pump impellers. The drill fixture consists of a locating plate and a threaded T-bar. See Illustration 1. These two pieces can be fabricated according to the FT1783 drawings.
Illustration 1. Components of FT1783 Drill Fixture.To use the FT1783 Drill Fixture, put the impeller in position on the plate. A vane of the impeller must be against the locator. See Illustration 2. Use the T-bar to hold the impeller in position. The drill fixture and impeller can then be put in position in a vise as shown in Illustration 3. Use a level to make sure the plate is perpendicular to the drill. Use the two holes in the fixture as guides, when 6.35 mm (.250") Ø holes are drilled.
Drawings of the FT1783 Drill Fixture are available from your Division Service Manager.
Illustration 2. Correct position of impeller in the drill fixture.
Illustration 3. Drill fixture in position in a vise.