FIRE PUMP - Continued
This task covers Repair
Shop Equipment, Automotive
MS178/69 Cotter Pin
Maintenance and Repair,
Fire Pump Removed from Truck
(see TM 5-4210-220-12)
Volute Body Removed (see para. 2-13.3)
Pump is made of aluminum alloy. Sealing surfaces will be damaged if pry bars or wedges are used to
disassemble components. When reassembling, do not force components into position or use fastener to
bring parts together.
Measure the wearing diameter of the
impeller in several places. If dimension (A)
is less than 6.975 in. (177.17 mm) at any
of the several points the impeller must be
replaced. If the impeller is to be replaced, it
is recommended that the wearing ring
diameter also be measured. See para. 2-
13.2 for procedure.
Remove the cotter pin (1), nut (2) and
washer (3). It will be necessary to hold the
drive flange at opposite end of pump shaft
(4) while removing nut (2).
Remove impeller (5) from splined shaft (4).
To install, ensure the carbon seal springs
(9) are in place.
Carefully slide impeller (5) onto pump shaft
(4). Make sure to aline the roll pin (7) in the
impeller with the hole in the spring seat (8).
Install washer (3) onto pump shaft (4).
Thread nut (2) onto pump shaft and tighten
firmly. Aline slotted nut with shaft hole and
install new cotter pin (1). Bend cotter pin
legs over the nut and toward impeller (5).
Install volute body as detailed in para. 2-
2-98 (2-99 Blank)