ENGINE AR-PRIMARY 4591674 - Caterpillar

Drain the coolant from the cooling system to a level below the exhaust manifold, into a suitable container for storage or for disposal. Refer to Operation and Maintenance Manual, "Cooling System Coolant (ELC) - Change" for the correct draining procedure.
Illustration 1 g03723187
Illustration 2 g03723190
Tighten sequence for M10 bolts and M8
Remove bolt (7) from clip for dipstick (5). Remove the dipstick from the engine oil pan. Refer to Disassembly and Assembly, "Engine Oil Pan - Remove and Install" for the correct procedure.
Gradually loosen bolts (2) for exhaust manifold (3) in the reverse numerical order to the tightening sequence. Refer to the Illustration 2. Support the exhaust manifold as the bolts are removed.
Gradually loosen bolts (1) for exhaust manifold (3) in the reverse numerical order to the tightening sequence. Refer to the Illustration 2.
Remove exhaust manifold (3) from the cylinder head.
Remove gasket (6) (not shown).
Illustration 3 g03723189
If necessary, follow Step 2.a through Step 7.h in order to disassemble the exhaust manifold (3).
If necessary, remove cooling system pressure sensor (7). Refer to Disassembly and Assembly, "Pressure Sensor (Engine Coolant) - Remove and Install" for the correct procedure.
If necessary, remove check valve (8). Refer to Disassembly and Assembly, "Check Valve - Remove and Install" for the correct procedure.
Make temporary mark on elbow connection (9). Loosen locking nut (10) and remove the elbow connection from exhaust manifold (3). Remove O-ring seal (11) (not shown).
Disconnect tube assembly (19) from elbow connection (17) and elbow connection (16).
Remove O-ring seal (18) (not shown) and O-ring seal (20) (not shown) from the connections.
If necessary, make temporary mark on elbow connection (17) and elbow connection (16).
Loosen locking nut (12) and locking nut (15). Remove elbow connection (17) and elbow connection (16) from exhaust manifold (3).
Remove O-ring seal (13) (not shown) and O-ring seal (14) (not shown) from the connections. Installation Procedure
Table 1
Required Tools
Tool Part Number Part Description Qty
A - Guide Bolts
M10 by 150mm 2
Ensure that the exhaust manifold, connections, and the tube assembly are free from wear, damage, and restriction.
Illustration 4 g03723189
If necessary, follow Step 2.a through Step 2.k in order to assemble the exhaust manifold (3).
Install a new O-ring seal (13) (not shown) and a new O-ring seal (14) (not shown) to elbow connection (17) and elbow connection (16).
Install elbow connection (17) and elbow connection (16) to exhaust manifold (3). Align the elbow connections with the temporary mark.
Install a new O-ring seal (18) (not shown) and a new O-ring seal (20) (not shown) to the connections. Ensure that the O-ring seals are correctly located into the recesses of the connections.
Connect tube assembly (19) to elbow connection (17) and elbow connection (16) Tighten the tube nuts hand tight. Adjustment of the elbow connections will be necessary in order to obtain the correct alignment of the tube assembly. Failure to align elbow connections correctly may result in damage to the elbow connections,
Use a suitable tool on the elbow connections and tighten locking nut (12) and locking nut (15) to a torque of 140 N m (103 lb ft). Ensure that the tube