1986/10/20 Caterpillar

Check Connecting Rods After Engine Failures Involving Hydraulic Lock{1218,1225}

Usage:

All Engines

Reference: Guideline For Reusable Parts SEBF8064, "Salvage Of Non-Serrated Connecting Rods."

Engines that experience failures from hydraulic lock in a cylinder may also experience bent connecting rods. Examples of failures involving a hydraulic lock in the cylinder may include aftercooler core leaks or cracked cylinder heads. Inspecting connecting rods during the first repair may prevent more severe failures caused by broken connecting rods.

Check connecting rods for bend, twist and pin bore to crankshaft bore distance on any cylinders that experience hydraulic lock. Also, use Magna Flux or a similar process to check the connecting rods for cracks.

Inspection for normal bend and twist should include the examples shown in Illustration 1.

Illustration 1. Example of twist and bend of a connecting rod.

Illustration 2 shows another type of bending damage associated with failures experiencing a hydraulic lock.

Illustration 2. Possible bending damage from hydraulic lock.

A close visual inspection should be made to determine any bending damage as shown in Illustration 2. Even if the connecting rod is only slightly bent, the pin bore to crankshaft bore distance may still be within specifications. For this reason the visual check is of increased importance and any questionable connecting rod should be replaced.

Inspection procedures given in the reference guideline should be closely followed to prevent failures from salvaged connecting rods.

Caterpillar Information System:

1986/10/20 Caterpillar Crankshaft Heat Code Locations{1202}

1986/10/20 Orifice Screen Assembly Now Used For The Timing Advance Mechanism{1251,1272,1288,1292}

1986/10/20 New Oil Pump Relief Valve Guide{1304}

1986/10/13 Remanufactured Final Drive Hubs And Housings (U.S. And Canada){4000,4002,4054}

1986/10/13 Water Level Switch Improved{1354,1350}

1986/10/13 New Piston Oil Ring Gives Better Oil Control{1215}

1986/10/13 New Service Tools Available{0600}

1986/09/29 Improved Damper Guard Used{1205}

1986/09/29 Use Correct Compression Seal Washer (Gas Seal) On 7000 Series Fuel Injection Nozzles{1254,1250}

1986/09/22 Improved V-Belts For Alternator{1405}

1986/09/22 More Flexible Lockwire Used With Nylon Seals For Sealing Critical Areas{1257,1264}

1986/09/22 Longer Adjusting Screw And Jamnut Available For Use In Valve Rocker Arms{1123,1105}

1986/10/27 Check Oil Drain Hole In OR2671 Or OR2621 Remanufactured Cylinder Heads If Head Used With Breather{1100,1300,1317}

1986/10/27 Stronger Oil Level Guide Used{1326,1300}

1986/10/27 New Indicator Instrument Group Available To Measure Crankcase Blowby And Radiator Air Velocity{0781,1200,1350}

1986/11/03 Custom Product Microfiche Library Is Now Part Of U.S. Product Parts Book Library {0374}

1986/11/03 New Jacket Water Heaters Have Longer Thermostat Life {1383,1450}

1986/11/03 High Loads Require Additional Oil Capacity {1318,1214,1215}

1986/11/03 Two New Cold Weather Fuel Heaters Available {1296}

1986/11/03 Nylon Seals Used On Lockwire To Seal Critical Areas; All Subsidiary Dealers Can Now Order Parts Service Seals {1257,1264}

1986/11/10 Caterpillar Antifreeze Now Used And Available From Parts Departments{1350,1395}

1986/11/10 New Fuel Ratio Control Used{1278}

1986/11/10 Adjust Bosch Solenoid If Replaced Or Reinstalled{1407,1453}

1986/11/10 Use Gas Detector Tubes That Have Expired Dates To "Break In" The Combustion Chambers For The Fuel Sulphur Analyzer Group{0651}