TM-9-2815-220-34 Direct Support Manual for AVDS-1790-2C and AVDS-1790-2D Engines Download

I engine oil cooler elbows ( 17) and (22) from each engine cooler. Remove and discard gaskets (20). (2) Remove six assembled washer hots (3, fig. 3-261) and remove left and right bank timing access covers (8) from left and right bank oil cooler support frames (7 and 22). (3) Remove two assembled washer bolts (3) and remove upper access cover (4) from left bank oil cooler support frame (22). (4) Remove three assembled washer bolts(3) and remove upper access cover (19) from right oil cooler support frame (7). c. Clecini11g. (1) Refer to paragraph 3-36. External surface of coolers may be cleaned using oil cooler cleaning tool Part No. 11641959. Clean throughly and blow dry with compressed air at 15 psi pressure. (2) Flush oil cooler assemblies with I dry-cleaning solvent (P-D-680, Type II). Blow dry with compressed air at a pressure of 15 psi. d. Ins71ection. Refer to paragraph 3-37. (1) Oil Cooler Assemblies. Inspect oil cooler as- semblies for dented tubing or bent fins. Inspect gasket contact surfaces for burs and raised metal. Seal all oil cooler openings. Pressure check coolers by pumping engine oil (OE) into coolers at 400 psi hydrostatic pressure. Coolers must hold 400 psi for ten minutes without loss of pressure. Release pres- sure, drain oil, and flush with dry-cleaning solvent 01: mi neral spirits paint thinner. Identify leaking coolers for possible repair. TM 9-2815-220-34 (2) Thermostatic byps valves. Inspect engine and transmission oil cooler thermostatic bypass valves for stripped or damaged threads. Check op- eration of valve assemblies by immersing valve in warm water. Check temperature of water with an accurate thermometer. Gradually raise tempera- ture of water to temperature indicated on valve cover. Valves marked 148?F. must travel 1/4-inch between 90°F. and I SO�F. Valves marked 185°F. must travel 1/4-inch- . . betwcen l 10°F. and 185°F. Remove valve from water and clean with dry- cleaning solvent or mineral spirits paint thinner. Replace valve assembly when travel is less than 1/4 inch. (3)0il cooler hoses. Inspect oil cooler outlet and inlet hoses for breaks and abrasions in woven shielding. Test hoses at 400 psi. Replace hoses that do not pass pressure test. (4)0il cooler screens. Inspect oil cooler screens for bent, cracked or broken mounting brackets. Check for torn or broken screening. Replace screens that are unserviceable. Straighten bent screens to as near original shape as possible. e. Ra. Refer to paragraph 3-38. Refer to par- agraph 3-3 and table 3-29 \vhcn replacing studs. NOTE  not repair leaks in oil coolers by I soldering. Soldering is not an acceptable repair because of the ltigh operating temperature and pressure. Table 3·29. Engine Oil Cooler Standarcl Stud lde11tificntio11 fi. Nu. lld. o. ning h�lght 3·260 20 2 Refer to figure 3-141 oversize stud 1dent1ficat1on. f. Assembly. NOTE The left bank lower engine oil cooler elbow (22, fig. '3-260) on Models AVDS-l 790-2C and AVDS-1790-20, is shorter than the upper engine oil cooler elbow (17). The left bank upper and lower engine oil cooler elbows (17) and (22' ) are the same length on Model AVDS-1 790-2DR. I1e right ba11k upper and lower engine oil cooler elbows on all model s are the same length as the left bank upper engine oil cooler elbow (17). (1) I n stall two new gaskets (20, fig. 3-260) , two engine oil cooler elbows (17) and (22) and secure with six self-locking nuts (18) on each cooler. lnstall new spacer rings (7) on transmission oil cooler thermostatic Oow control v alves (9). Install valve assemblies . Cnstall new spacer rings (7) on two enne oil cooler thermostatic valve assemblies (8). Install valve assemblies. No. t'd Stu� site a length 12 5116-18 (116) x 5116-24 (13116) x 2-?4 (2) Install left timing access cover (8, fig. 3-261) on left oil cooler support frame (22) and secure with three assembled washer bolts (3). Install right access cover in the same manner. (3) Install right bank upper access cover plate (19) on right oil cooler support frame (7) and secure with two assembled washer bolts (3). (4) Install left bank flywheel end upper access cover (4) on left bank oil cooler support frame (22) and secure with two assembled washer bolts (3). 3·112. Repair of Engine Cooling Fan and Associated Parts a. Disassembly. Remove sixteen cotter pins (6, fig. 3-262), slotted nuts (18) flat washers (7) and machine bolts (8) attaching cooling fan hub to fan. Separate fan (16) from hub (17). NOTE The machined face of the fan is marked "TOP" to insure correct assembly. Change 3 3·169