Section II. PRIMER PUMP ASSEMBLY - TM-5-4210-213-350043

Section II. PRIMER PUMP ASSEMBLY

3-10. General

e. Inspection and Repair. Inspect all parts for

The priming system consists of a rotary vacuum pump

wear, defects, and damage. Replace or repair worn,

operated by a 24-volt electric motor controlled through a

defective, or damaged parts as necessary.

priming pump valve mounted in the pump compartment,

f. Reassembly

Refer to figure 3-9 and

a microswitch mounted on the priming pump valve, and

reassemble the primer pump assembly in the reverse

a master control switch mounted on the pump control

order.

panel. As the priming valve is actuated the microswitch

g. Installation. Install the primer pump assembly

starts the priming pump motor. The priming pump

(TM 5-4210-213-12).

motor drives the primer pump which sucks water into the

centrifugal type fire pump suction lines, priming the

3-12. Primer Valve

pump. After both the suction and discharge casings

a. General. The primer valve controls the primer

have been completely filled, water is then discharged

pump.

through the bottom of the primer pump, and the primer

b. Removal. Refer to figure 3-1 and remove the

pump must be manually shut off.

primer valve from the pump assembly.

3-11. Primer Pump Assembly

c. Disassembly.

Refer to figure 3-10 and

a. General. The primer pump primes the fire

disassemble the primer valve.

pump.

d. Cleaning. Clean all parts in an approved

b. Removal. Remove the primer pump assembly

cleaning solvent and dry thoroughly.

(TM 5-4210-213-12).

e. Inspection and Repair. Inspect all parts for

c. Disassembly.

Refer to figure 3-9 and

wear, defects, and damage. Replace or repair worn,

disassemble the primer pump assembly.

defective, or damaged parts as necessary.

d. Cleaning. Clean all parts in an approved

f. Reassembly.

Refer to figure 3-10 and

cleaning solvent and dry thoroughly.

reassemble the primer valve in reverse order.

g. Installation. Refer to figure 3-1 and install the

primer valve on the pump assembly.

Section III. FIRE PUMP ASSEMBLY

3-14. Pump Gearbox

3-13. General

The fire pump assembly consists of a main pump,

a. General. The fire pump gearbox contains

drive unit and relief valve. The main pump includes the

driving gears and bearings to transmit power to the fire

impeller, main shaft, main bearings and head, suction

pump.

and discharge pipes, and volute case. The drive unit

b. Removal.

contains driving gears and bearings for the main pump,

(1) Remove universal drive shaft (TM 5-

which is driven by the power takeoff unit on the truck

4210-213-12).

transmission. A series of vanes on the rapidly rotating

(2) Refer to figure 3-11 and remove the pump

impeller produce centrifugal force, which forces the

gearbox from the pump assembly.

water through the inside of the impeller, this increases

c. Disassembly.

Refer to figure 3-12 and

the pressure of the water and creates a vacuum which

disassemble the pump gearbox.

draws more water into the impeller. The relief valve

d. Cleaning. Clean all parts in an approved

bypasses water within the pump to prevent pressure rise

cleaning solvent and dry thoroughly.

when the hose lines are shut off.

e. Inspection and Repair. Inspect all parts for

wear, defects, and damage. Replace or repair worn,

defective, or damaged parts as necessary.

3-18