Operation in Humid Climates

TM 10-3930-633-12

(5) Clean spark plugs and check gaps.

closed building with some heat, if possible. If this

(6) Be sure terminal sockets and spark plug

is not possible, cover with a tarpaulin or similar

terminals are clean.

kind of material.

d. Lubrication. Make certain that tractor is

b. Cooling System. Add proper amount of

serviced in accordance with instructions of the

ethylene glycol antifreeze to cooling system. A

Lubrication Order LO 10-3930-633-12.

solution of 7 quarts ethylene glycol and 7

e. Fuel System.

quarts of water will afford protection at 350 F

(1) Drain the fuel filter often to expel

( 37 C). If antifreeze is not available, drain

trapped moisture and prevent icing.

radiator and cylinder block when ambient tem -

perature is expected to drop below 32 F (O 0 C).

(2) Fill the fuel tank at the end of each period

of operation to expel trapped moisture and

Never add water to the cooling system without

prevent condensation of water in the fuel tank.

subsequently checking the antifreeze solution for

adequate strength and adding antifreeze if

2-12. Operation in Humid Climates

necessary.

In tropical areas, if paint is chipped, or scratched,

c. Electrical System.

the affected area should be refinished immediately

(1) Test the specific gravity of the electrolyte

to prevent rapid formation of rust. Remove all

in the battery, using a hydrometer. Specific

loose paint with paint remover, sandpaper, or

gravity reading should be between 1.260 and

sandblasting equipment. Apply two coats of red

1.275 at 80 F (26.7 C).

lead primer and, when dry, apply finishing coat of

(2) Electrolyte lever of battery must be

paint.

maintained at inch above plates. Do not add

2-13. Operation in Dusty Conditions

water to a battery which has been exposed to cold

temperature except when engine is to be operated

Operators of tractors used in extremely dusty

immediately.

conditions should check the air cleaner daily to

(3) Remove battery and store it in a warm

insure that excessive build-up of dust or dirt,

place when shelter for truck is not available. The

which would restrict air flow, is not permitted.

Lubrication service intervals for all items should

efficiency of the battery decreases at lower

be reduced to one-half the normal period, or as

temperatures, a n d a completely discharged

short as 50 hours, depending upon the severity of

battery will freeze at 20 F.

(4) Be sure that wires and cables are in good

the service.

condition and that all connections are clean, dry

and secure.

2-4