Section IV. REPAIR

Section IV. REPAIR

(7) If difficulty is experienced in cleaning tube-

3-26.

General

header fin-side area, repeat use of muriatic acid, heat and

flux. Dirt and oxides are washed away by brushing with

The step-by-step repair procedures included in this

this method In extremely difficult instances, an abrasive

chapter are effected after the unit has been removed from

blasting gun may be required.

the vehicle, vat cleaned, dried of all moisture and the leaks

(8) When repair area is absolutely clean and

located.

tinned, position radiator so that header is level and fin side

to be soldered is facing upward.

3-27.

Resolder Header Top Corners

(9) Begin heating and flowing solder about the

header and tube joints. If radiator has three or more rows

a. General. The most frequent location of leaks is

of tubes, begin heating and flowing solder about the

at the top corners of the radiator. When leaking, these

header and tube joints. If radiator has three or more rows

corners should be completely resoldered. Resoldering

of tubes, begin with innermost tubes. As solder flows

should include two or three additional tubes adjacent to the

around innermost tubes, withdraw torch slightly to control

leaky ones.

heat. Continue soldering outer tubes in a similar manner.

See Figure 3-10 for Illustration of resoldering tubes into

Repair Procedure (Tanks not Removed).

header from fin side.

WARNING

There is a danger to personnel from hot blowing

solder. Wear safety goggles, rubber shoes and

rubber apron while blowing solder.

CAUTION

To blow away hot solder, apply point of torch flame

to header and not the tubes. As the older solder

melts, use blast of air from air blow gun. Repeat

this process until all solder is removed.

CAUTION

Do not overheat fins If they are heated to red, they

will burn away. Apply only enough heat to melt

solder.

(1) After leak testing, raise radiator from test

Figure 3-10. Resoldering header from fin side.

tank and remove air pressure. Blow water from external

fins and place radiator in upright position with fin side of

(10) Continue air testing and repairing until all

header facing upward.

leaks are repaired. Wash thoroughly to remove acid and

(2) Heat and raise fins in the area to be

flux residue.

repaired if necessary. Heat fins slowing in repair area.

c. Reinforcements.

Tube reinforcements add

(3) Raise unbonded fins in repair area no more

structural rigidity to the tube-header junctions. These clips

than 1/2 inch Do not force fins but pry them only while

are formed from copper wire and can be placed around

solder bond is melted.

the tubes at the tube-header junctions and soldered in

(4) Clean entire area by heating and removing

place. They are more necessary around the corner tubes

hot solder from tube-header junctions with air blow gun.

where stress is greatest. The possibility of leaks occurring

(5) After solder is removed, flush and clean by

again is further reduced by use of these clips.

squirting muriatic acid on repair area. Use syringe type

squirt bulb made for this purpose. Apply flux with large

3-28.

Resolder Entire Header

flux brush and clean between tubes with radiator brush.

a. To resolder entire header, use the preceding

(6) Apply tinning mixture with swabbing brush

method for cleaning, tinning, and soldering (para 3-27).

and heat base of tubes along edge of header. Alternate

After cleaning and tinning, began at one end of header and

use of flux and tinning mixture will give best results.

flow solder continuously around each

Continue tinning until entire fin side of header is bright and

clean.

3-10