SEAT GP-SUSPENSION 2735422 - Caterpillar

The 28 mm (1.1") orifice in the outlet elbow is a restriction to the coolant flow. This slows the coolant flow rate to permit better venting (discharge of air in solution in the coolant, into the air chamber at the top of the radiator).
Formerly, an elbow without an orifice was used.
In certain heavy load applications, it was possible for the coolant to flow fast enough to prevent good venting. Too much air held in solution in the coolant some times caused water pump cavitation (reduction of water flow). The result was engine overheating.
Adaptable As: The new elbow is a direct replacement for the former elbow as shown in the charts. If an engine has a combustion gas leakage into the cooling system and/or if the radiator cap does not hold pressure, check for high operating temperatures and low cooling system pressure. High operating temperatures and low cooling system pressures are conditions which can cause water pump cavitation. If the operating temperatures are high and the cooling system pressure is low, it is Caterpillar's recommendation to install an elbow with an orifice.

Parts seat Caterpillar catalog:

1376715 SEAT-VALVE SPRING
120H, 120K, 120K 2, 12K, 12M, 135H, 140G, 140K, 140K 2, 140M, 160K, 3126, 3126B, 3126E, 322C, 322C FM, 324D, 324D FM, 324D FM LL, 324D L, 324D LN, 325C, 325C FM, 325D, 325D FM, 325D FM LL, 325D L, 325...

3214946

3214946 SEAT
307D, 308D

3166193

3166193 SEAT
307D, 308D, 308E CR

3166189

3166189 SEAT
307D, 308D, 308E CR

3166190

3166190 SEAT
307D, 308D, 308E CR

3276540

3276540 SEAT BELT GP
307D, 311D LRR, 311F LRR, 312D, 312D L, 312D2, 312D2 GC, 312D2 L, 312E, 312E L, 313D2, 314D LCR, 314E CR, 314E LCR, 315D L, 316E L, 318D2 L, 318E L, 319D L, 319D LN, 320D, 320D FM, 320D FM RR, 320D GC...

3054883 SEAT
311D LRR, 312D, 312D L, 313D, 314D CR, 314D LCR, 315D L, 318D L, 319D, 319D L, 319D LN

3054884 SEAT
311D LRR, 312D, 312D L, 313D, 314D CR, 314D LCR, 315D L, 318D L, 319D, 319D L, 319D LN

2155034

2155034 SEAT
308E SR, 311D LRR, 311F LRR, 312D, 312D L, 312E, 314C, 314D CR, 314D LCR, 314E CR, 314E LCR, 315D L, 316E L, 319D L, 320E, 320E L, 320E LN, 320E LRR, 320E RR, 321D LCR, 323E L, 324E, 324E L, 324E LN, ...

3698508

3698508 SEAT
318E L, 320D, 320D FM, 320D GC, 320D L, 320D LN, 320D LRR, 320D RR, 320D2, 320D2 GC, 320D2 L, 320E, 320E L, 320E LN, 320E LRR, 320E RR, 321D LCR, 323D L, 323D LN, 323D SA, 323D2 L, 323E L, 324D, 324D ...

2941679

2941679 SEAT
320D, 320D FM, 320D FM RR, 320D GC, 320D L, 320D LN, 320D LRR, 320D RR, 321D LCR, 323D L, 323D LN, 323D SA

2941680

2941680 SEAT
320D, 320D FM, 320D FM RR, 320D GC, 320D L, 320D LN, 320D LRR, 320D RR, 321D LCR, 323D L, 323D LN, 323D SA

3028813

3028813 SEAT GP-SUSPENSION
120H, 120H NA, 12H, 12H NA, 135H, 135H NA, 140H, 140H NA, 143H, 14H, 14H NA, 160H, 160H NA, 163H, 16H, 16H NA

2735425

2735425 SEAT GP-SUSPENSION
308D, 314D CR, 314D LCR, 320D L, 321D LCR, 328D LCR

1555958

1555958 SEAT GP-SUSPENSION
120H, 120H ES, 120H NA, 12H, 12H ES, 12H NA, 135H, 135H NA, 140H, 140H ES, 140H NA, 143H, 14H, 14H NA, 160H, 160H ES, 160H NA, 163H, 163H NA, 16H, 16H NA

1751503

1751503 SEAT GP
120H, 120H NA, 12H, 12H NA, 135H, 135H NA, 140H, 140H NA, 143H, 14H, 14H NA, 160H, 160H NA, 163H, 16H, 16H NA

1753583

1753583 SEAT GP-COMPANION
784C, 785C, 789C, 793C

1175277

1175277 SEAT GP-COMPANION
769D, 771D, 773D, 775D, 776D, 777D

9r5714

9R5714 SEAT GP-STATIC
416, 426, 428, 436

9k3742

9K3742 SEAT GROUP
920, 930

3579647

3579647 SEAT GP-SUSPENSION
836H