Core Repair; Cmcac Preventive Maintenance - Mack E7 Service Manual

5-101.bk Page 9 Friday, March 17, 2006 11:05 AM
200 ENGINE INSTALLATION & TESTING
Damage
Repairable All header tank-to-core separations
All header tank cracks
Bent cold fins
Tube plate cracks or welds not
exceeding 0.25 inch (6.35 mm) in
length
Tube cracks or weld separations
exceeding 0.25 inch (6.35 mm) in
length
Nonrepairable Internal fins damaged and
separated from tube plate
Tube blockage
Cold bar separations or openings
exceeding 0.25 inch (6.35 mm) in
length
Excessive cold fin damage (original
shape of fins distorted beyond
repair)
INSPECTION
1. Carefully inspect entire system to determine
exact location and extent of damage.
2. Inspect cold fins and cold bars that run
horizontally in cooler.
3. Inspect all brazed or welded joints in header
tank.
4. Make sure area to be repaired is free of
surface oxide and foreign materials such as
oil, grease, dirt, etc. Prior to repair, prepare
surface with a clean stainless-steel brush.
TUNGSTEN-INERT (TIG) WELD METHOD
TIG-weld using 1/16–5/32 inch diameter
AWS ER 4043 filler rod. Welds should exhibit
complete fusion without excessive overlap or
undercut.
MACK recommends pressure-testing the
CMCAC system after repairs are complete.
Core
Failures Repair Procedure
Tungsten-Inert (TIG) weld method
Tungsten-Inert (TIG) weld method
Straighten with small screwdriver or
pair of small needlenose pliers
RTV method or Tungsten-Inert
(TIG) weld method
Tungsten-Inert (TIG) weld method
No repair procedure is
recommended — replace unit
No repair procedure is
recommended — replace unit
No repair procedure is
recommended — replace unit
No repair procedure is
recommended — replace unit

CMCAC Preventive Maintenance

In case of engine and/or turbocharger failure,
perform the following steps to make sure CMCAC
system is free from debris:
1. Remove chassis-mounted cooler and flush
2. Shake cooler to remove large pieces.
3. Wash with hot soapy water. Rinse with clean
4. Carefully inspect cooler to ensure
Recommended
Perform pressure/leak test
Perform pressure/leak test
Perform pressure/leak test
Perform pressure/leak test
Perform pressure/leak test
Perform pressure/leak test
Perform pressure/leak test
Perform pressure/leak test
Perform pressure/leak test
inside with a safety solvent to remove oil and
other foreign debris.
water and blow dry with compressed air in
reverse direction of flow.
cleanliness. Do not use caustic cleaners.
System
Check
205218
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