SWITCH AS-PRESSURE 2305771 - Caterpillar

1.1 Liter Family (3114, 3116) Of EnginesSUPPLEMENT: 02/26/90SERVICE MAGAZINE; MAY 15, 1989; PAGE 5; "New Valve Stem Seal Used On Inlet Valves And Added To Exhaust Valves" on 1.1 Liter Family (3114, 3116) Of Engines.The new spring retainers and the interim 9Y7355 Seats are also effective with 3114 (1ZG431) Industrial Engine, 3116 (4PG581) Industrial Engine and 3116 (4TF634) Vehicular Engine. The new seals are also effective with 3114 (1ZG433) Industrial Engine, and 3114 (2FG133, 2ZF93) Vehicular Engines, 3116 (4PG588) Industrial Engines, and 3116 (4TF745, 1CK671) Vehicular Engines.--------------- END SUPPLEMENT ---------------SUPPLEMENT: 10/09/89SERVICE MAGAZINE; MAY 15, 1989; PAGE 5; "New Valve Stem Seal Used On Inlet Valves And Added To Exhaust Valves" on 1.1 Liter Family Of Engines.Unde the topic "Adaptable To", add the following serial numbers for the interim engines: 3114 Industrial Engine: 1ZG4313116 Industrial Engine: 4PG5813116 Vehicular Engine 4TF634Add the following serial numbers for the new seals in the second list:
3114 Industrial Engine: 1ZG4333116 Industrial Engine: 4PG5883114 Vehicular Engine: 2FG133, 2ZF933116 Vehicular Engine: 4TF745, 1CK671--------------- END SUPPLEMENT ---------------SUPPLEMENT: 06/19/89SERVICE MAGAZINE; MAY 15, 1989; PAGE 5; "New Valve Stem Seal Used On Inlet Valves And Added To Exhaust Valves" in 1.1 Liter Family Of Engines.Refer to the third paragraph on Page 6. The last sentence should read: "Turning the crankshaft 180° counterclockwise (CCW) moves pistons 2 and 3 to TDC."--------------- END SUPPLEMENT ---------------Description of Change: A new valve stem seal is used on the inlet and exhaust valves in the 1.1 Liter Family of Engines. (Formerly, a seal was not used on the exhaust valve stem.) The valve spring sits on top of the new seal flange, and this requires a different spring retainer to maintain the same compressed spring length. See Illustration 1.
Illustration 1. The new valve stem seal assemblies with the new spring retainers now used on the inlet and exhaust valves.The former seal formed only an "umbrella" over the end of the valve stem guide. The former seal was not retained and thus it could slide up and down with the valve and become ineffective. The new seal seats directly on the head, and is held in this position by the force of the valve spring.
As an interim change, the new spring retainer was used with the FORMER seal. Since the new retainer was designed for use with the new seal that has a flange under the spring, a 9Y7355 Seat (Spacer) is required to maintain the same compressed spring length on these interim engines. See Illustration 2.
Illustration 2. The interim change where the new retainers are used with the separate spring seats on both valves, but the former seal was still used only on the inlet valve as shown.Adaptable To: The new spring retainers and the interim 9Y7355 Seats are effective with: (interim engines) 3114 Ind. Engine: 5EF482, 1ZG (not available)3114 Standby Generator Set Engine: 6AF4703114 Generator Set Engine: 5JG4733116 Ind. Engine: 2WG546, 4PG (not available)3116 Standby Generator Set Engine: 2SG6433116 Generator Set Engine: 1NJ5763114, 3116 Cat Vehicular Engines (not available) The new seals are