ELBOW 2686293 - Caterpillar

(74Z),
776B (6JC),
776C (2TK) Tractors;
777B (4YC),
777C (4XJ),
785 (8GB),
785B (6HK),
789 (9ZC),
789B (7EK),
793 (3SJ) 793B (1HL) Trucks;
994 (9YF) LoadersReference: Service Magazine; June 20, 1988; Page 1; "Troubleshooting Automatic Ether Starting Aid."Service Magazine; December 19, 1988; Page 4; "Cold Weather Readiness Checks."
Service Magazine;November 18, 1991; Page 5; "New Two Piece Piston Used In 3508 (99W), 3512 (96Z), And 3516 (54Z) Vehicular Engines."
Service Magazine; March 22, 1993; Page 7; "New Piston And Rod Group Has Lower Top Ring Position And Improved Ring Groove Cooling."
Reference: Service Manual, Automatic Ether Injection System, SENR4705-02.The purpose of this article is to again emphasize the important points about cold weather operation of the 3500 Engines in the above machines.
1. One of the most important points for the operation of 3500 Engines in cold weather is that starting assistance is needed at temperatures 13°C (55°F) and below for engines that have mechanical unit injection (MUI) fuel systems and one piece pistons..Cold starting presents the most severe rough combustion conditions. Rough combustion can produce white smoke and excessively high cylinder pressures. This can result in piston scuffing.
2. The proper use of the ether starting aid system will assist the 3500 Engines to start quicker in cold weather. This will limit the intervals of rough combustion.3. In machines equipped with engines that have MUI fuel systems and one piece pistons, ether is needed at temperatures of 13°C (55°F) and below to avoid engine damage from rough combustion. The proper use of the ether system will assist the engine to start quicker. This will reduce the duration and severity of white exhaust smoke and also minimize the potential of piston damage.4. In machines equipped with engines that have MUI fuel systems and two piece pistons, or engines with Electronic Unit Injection (EUI) fuel systems, ether is needed at temperatures of 0°C (32°F) and below to avoid engine damage from rough combustion. For temperatures between 13°C (55°F) and 0°C (32°F), the ether system will assist the engine to start quicker. This will reduce the duration and severity of white exhaust smoke.Maintenance of the MUI timing adjustment and the cylinder head valve adjustments will help provide the smoothest possible combustion as well as minimize peak cylinder pressures.
Check the ether starting system on a regular basis to insure the system is functional. Inspect all the ether line connections and the ether cylinder(s) seal. Also check to be sure the ether cylinder(s) contain ether. A full 7X-1062 Ether Cylinder Assembly weighs about 1047 g (37 oz) and an empty cylinder weighs 453 g (16 oz). Because the rate of ether consumption will vary depending upon the number of starts and the ambient temperature, it is suggested the ether cylinders be checked weekly until a specific maintenance schedule can be established.