(1) Remove radiator cap, then open drain
3-20. Radiator Service
cocks on radiator and engine block.
a. Maintaining Water Level. Remove radiator cap,
(2) When engine and radiator is fully drained,
add water until it stands two inches below over flow,
close all drain cocks.
then install radiator cap.
(3) Fill system with clean water until it stands
b. Draining, Cleaning, Flushing, Neutralizing, and
two inches below the over flow. Install radiator cap.
Filling. Refer to TB ORD 651 (Use of Antifreeze
Solutions and Cleaning Compounds in Engine Cooling
3-21. Fan Drive Belt Adjustment
Systems) for instructions on cleaning, flushing, and
a. On Engine Model 687C-18-ES.
neutralizing radiator. Drain and refill as described
(2) Increase belt tension by turning setscrew
Loosen belt by turning setscrew
Note. Proper adjustment will allow belt to
depress from 3/4 to one inch at a point midway
between pulleys, while using a moderate pressure.
(3) When proper adjustment is attained tighten
the four capscrews and locknut.
b. On Engine Model D3S3TA.
(1) Loosen the two bracket retaining bolts
which hold idler hub bracket to timing gear cover (view
(2) Loosen locknut on adjusting screw and turn
adjusting screw clockwise until the two belts can be
depressed approximately 1/2 inch midway between
pulleys with a force of approximately 25 pounds.
(3) When adjustment is correct, tighten the two
bracket retaining bolts and locknut.
Figure 3-21. Fan drive belt adjustment (sheet 2 of 2).
Figure 3-21. Fan drive belt adjustment (sheet 1 of 2).