core passages inside the radiator are clogged with rust, sediment, and scale, flush the radiator with a recommended
inhibitor.
Note. Avoid extremely high water pressure when flushing the radiator, as it may distort the radiator core.
Clean the draincock with compressed air or water. When cleaning the draincock with compressed air, make sure that the
pressure does not exceed 90 psi and hold the nozzle 1 inch from the radiator. When cleaning with water, make sure that
the pressure does not exceed 80 psi and hold the nozzle 3 inches from the radiator. Clean the accumulated dirt and rust
from the mounting bolts, nuts, and lockwashers. Replace bolts, screws, and nuts if worn out, stripped, or damaged.
e. Inspection and Repair.
(1) Clean the radiator and plug the upper inlet and the overflow pipe. Tighten the radiator cap.
(2) Insert an air hose in the lower outlet pipe and caulk it securely with cotton waste.
(3) Immerse the radiator in a tub of water and apply 5 pounds' pressure.
Note. Do not use higher air pressure than 5 pounds per square inch, as it may damage the radiator core.
(4) Watch for air bubbles. When they appear, mark the point of origin.
(5) Solder the leak carefully. Do not use excess solder and do not permit the solder to leak into the radiator
core passages because it may obstruct or clog the water flow.
(6) If the radiator core is badly damaged, replace it with a new one. Always install new top and bottom gaskets
when disassembling or reassembling the radiator.
(7) Inspect the radiator hoses for worn, cut, swollen, or peeling rubber. Check the inside surface of the hoses
for breaks, cracks, and damage. Replace defective or swollen hoses.
(8) Inspect the hose clamps for breaks, cracks, corrosion, and damaged or worn clamp screws. Replace worn
or damaged hose clamps.
(9) Check the radiator plates for breaks, cracks, twisting, and warpage. Weld small breaks and cracks. Be
careful and do not apply too much heat when welding, as it may cause the plates to warp. Grind, clean, and
paint the welds. Replace the radiator plates if they are badly broken, dented, or if the mounting holes are
worn or elongated.
f. Reassembly (fig. 44).
(1) Coat the outlet elbow gasket with fast-drying gasket sealer and install the water outlet elbow (16) on the
bottom tank (17). Install and tighten the lockwashers (3) and screws (2).
125
