Engine Cooling System; General; Radiator Cap; Removal - Hobart 140GT17P Operation And Maintenance Manual With Illustrated Parts List

6. Engine Cooling System

A. General
Cooling system device requires much more than maintaining the proper coolant level in the radiator.
During warm seasons and in warm climates, plain water can be used as a coolant if the system is
protected against rust by a rust inhibitor additive. During cold seasons and in cold climates, the sys-
tem must, of course, be protected against freezing. At no time should the system be operated for any
length of time on plain water, without a rust inhibitor or antifreeze. Draining, cleaning, and filling the
cooling system are covered in Para. 6, E through H.
B. Radiator Cap

(1) General

A pressure valve is built into the radiator cap. It is designed to open at a pressure of approxi-
mately seven pounds per square inch.

(2) Removal

To remove, turn the cap to the left (counterclockwise) to the safety stop. When all pressure is re-
leased, press down on the cap and continue to turn until the cap is free to be removed.
WARNING: HOT STEAM AND FLUIDS WILL SEVERELY BURN! WHEN RE-
MOVING CAP FROM A VERY HOT RADIATOR, DO NOT TURN CAP PAST
SAFETY STOP UNTIL ALL PRESSURE OR STEAM HAS ESCAPED. USE PRO-
TECTIVE CLOTHING. ALLOW ENGINE TO COOL BEFORE ADDING COOL-
ANT.

(3) Installation

When installing the cap be sure it is turned clockwise as far as it will go so that the pressure re-
taining valve will be functional.
C. Warm Weather Operation
During warm weather operation, if water is used in the cooling system instead of an antifreeze solu-
tion, keep the cooling system free of rust and sludge by adding a cooling system conditioner that is
compatible with aluminum. Instructions for use of the conditioner are printed on each can.
CAUTION: USE ONLY A CORROSION INHIBITOR THAT IS COMPATIBLE WITH ALUMINUM. DO NOT
USE INHIBITORS LABELED AS "ACID NEUTRALIZER".
D. Cold Weather Operation
(1) General
A permanent type, (Ethylene Glycol) antifreeze is recommended for use in the cooling system.
September 30/89 Revised
OM-2029
2-1
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