1996/12/02 Caterpillar

Check Turbocharger Seals If There Is A Sudden Increase In Crankcase Blowby {1052,1317}

Usage:

Challenger 75 (4CJ),
Challenger 75C (4KK),
Challenger 75D (5AR),
Challenger 85C (9TK),
Challenger 85D (4GR) Agricultural Tractors

If an engine in one of these machines is producing the correct power and running well, but SUDDENLY develops excessively high blowby, check the turbocharger shaft seals. The failure of a turbocharger shaft seal may allow inlet manifold boost pressure to be felt in the turbocharger oil drain line. This could result in excessively high blowby.

Many times when service personnel troubleshoot an engine that has excessive blowby, they assume the cause is piston ring and cylinder bore wear. This is usually a slow wearing process that results in a gradual increase in blowby. Usually, when a turbocharger shaft seal fails the result is a SUDDEN increase in blowby.

Caterpillar Information System:

1996/11/25 Procedure For Installing Steel Core Gasket At The Front Housing And The Flywheel Housing {1151,1157,1162}

1996/11/25 Inspection of Tire Stems When Using Calcium Chloride Ballast Prevents Tire Failures {4203,4231,4207}

1996/11/25 Dowel, Pin or Piston Limits Poppet Valve Movement In Relief Valve Groups {5072}

1996/11/25 Blade Lift Cylinder Improved {5102}

1996/11/25 Install Additional 8Y-6388 Louver Assemblies to Improve Defogging of Cab Windshield {7304,7309,7310,7451}

1996/11/25 Rotate 8Y-6388 Louver Assemblies in Heater Group to Improve Service Life {7304,7309}

1996/11/25 Special Instruction, SEHS9926, "Installation of Turbocharger Debris Shields" Available {7263,7154,7158}

1996/11/18 New Service Parts For The Front And Rear Drive Shaft Groups For Improved Reliability{4074}

1996/11/18 Measure Vibration Of Vibratory Compactor Drums With Hand Held Meters{7471,0783}

1996/11/18 Radiator And Oil Cooler Mounting Improved{1351}

1996/11/18 New Stud Available For Gear Pump Group{5073}

1996/11/18 New Brake Adjustment Procedure For Improved Inching Ability {3162,4115,4250}

1996/12/02 Special Instruction REHS0029 Available To Modify Radiator Support And Guard Group To Provide Cleanout Access For Radiator {1353,7272}

1996/12/02 New Retainer Screws Prevent Contact With Seat Back On Cab Recirculation Filter {7342}

1996/12/02 Ground Strap Relocated To Prevent Damage From Debris {7423}

1996/12/02 Overfill Of Hydraulic Tank May Cause Oil Leakage {7479,1460}

1996/12/02 New Front Park, Turn Lamp Is Available That Is Not Affected By Vibration {1430}

1996/12/02 Improved Relay Switch Assembly Used To Provide Increased Reliability {1423}

1996/12/02 New Drive Train Lubrication Updates {3251,3252,3253,7568,7581}

1996/12/02 New Assembly Procedure For Rotate Carriage Groups {6408,6405,6460}

1996/12/02 Improved Relay Switch Assembly Used To Provide Increased Reliability {1423}

1996/12/02 Improved Relay Switch Assembly Used To Provide Increased Reliability {1423}

1996/12/02 New Housings Are Available In Regulator Housing Groups {1393}

1996/12/09 Rotate Crankshaft On 3114, 3116 And 3126 Engines Using 9U-6943 Gear Shaft Housing Assembly Or 9U-7336 Gear Shaft Housing Assembly {1202,0701}