TASK 70-21-27-110-001
1 . General
A.This cleaning process makes use of a mild organic bath (coconut oil soap), active when hot, used to dissolve light soils including oil sludge and baked oil varnish. The bath is safe for most metallic and non-metallic materials, including, but not limited to, Sump Housings, Heat Shields, Carbon Bearing Seals, Carbon Seal Rings, and Electrical Rotors and Stators.
2 . Equipment.
Subtask 70-21-27-110-002
B.The following equipment is required for the application of this process.
(1)Safety equipment and devices that are standard equipment in surface treatment shops such as: eye bath, emergency showers, and protective clothing.
(2)A cleaning tank made from stainless steel with a heating coil that is capable of heating the solution to 210°F (99°C). An ultrasonic cleaning tank may also be used per the requirements in TASK 70-21-15-130-001, Cleaning Method No. 15 - Ultrasonic Cleaning.
(3)A water rinse tank made from stainless steel (or a carbon steel tank with a polypropylene lining) and an air/water spray gun.
3 . Materials.
Subtask 70-21-27-110-003
C.Solution for removal of baked oil and carbon deposits:
 
Coco Oil Solution - Table 1
 
Solution
Concentration
Operating Temperature °F (°C)
 
Coco Oil Soap C04-028
1 part Coco Oil Soap to 7 parts water
180-210 (82-99)
4 . Procedure.
Subtask 70-21-27-110-004
NOTE:
In case C04-028 cannot be supplied, it is recommended to use one of the following cleaning methods: Refer to TASK 70-21-01-110-001, Cleaning Method No. 1 - Solvent Degreasing, TASK 70-21-14-110-012, Cleaning Method No. 14 - Manually-Assisted Detergent Cleaning, or TASK 70-21-22-110-801, Cleaning Method No. 22 - Light Duty Aqueous Cleaning.
D.Immerse the part in a tank containing the coco oil solution listed in Table 1. Maintain the solution at the specified temperature.
(1)Soak the part in the solution for 2 to 12 hours or until the oil soil becomes loose and can be removed with a stiff, non-metallic brush or rag.
WARNING:
PARTS WILL BE HOT. USE PROPER PERSONAL PROTECTION EQUIPMENT INCLUDING FACE SHIELD, GLOVES, PROTECTIVE CLOTHING AND PROTECTIVE SHOES.
E.Drain the part over the cleaning tank to allow the excess solution to drain back into the tank.
F.Rinse/flush the part with water and then drain. Repeat the process if necessary.
G.Dry using clean, dry air or oven bake at 250°F (121°C) for 2 to 4 hours to remove moisture.
H.Use an appropriate rust preventative if the material is prone to rust per TASK 70-60-00-620-001, Preservation of Engine Parts.
5 . Quality Assurance.
Subtask 70-21-27-110-005
I.Visually check for the removal of all traces of carbon coking residues from the part.
(1)Make sure that all loose contaminates are removed from any blind internal passages in the hardware. This can be accomplished by flushing the passages with a general solvent: C04-001, C04-002 , C04-003 , or alcohol C04-014 or C04-035 and filtering the flush solution. Examine the flush solution for visible particles. If visible particles are present, repeat the cleaning process and re-inspect the part.