Improved Exhaust Valve Now Available{1105}
Usage:
3406, 3408, 3412 Engines in All Applications
Description of Change: A different method is now used to make the stem and head of the exhaust valve straight. In addition, a different heat treatment is used to prevent damage to the silicon material in the head of the valve. The method used to make the stem and head straight on the former exhaust valve some times caused hard spots and stress in the valve. Because of these stresses, failure of the valve was possible.
Adaptable As: The new 7N2271 Valve is a direct replacement for the former 4N5653 Valve which is canceled.
The new valve was "First Used" as shown in the chart that follows:
Caterpillar Information System:
1977/02/28 Lock Now Available For Connecting Rod Bolt Used In TU-FL0501 Air Compressor{1065}
1977/02/28 Clip Now Used To Hold Coolant Line For The Turbocharger{1052,1380}
1977/02/28 Hardened Washers Now Used Between The Bolt Heads And The Engine Front Support To Keep These Bolts Tight{1153}
1977/02/28 Modification To Holder To Machine Counterbore On Cylinder Block{0664,1201}
1977/02/14 Diesel Fuel Recommendation Expanded{1280}
1977/02/14 Test Used Fuel Nozzles Before You Install New Nozzles; Tips On Test Procedures{1254,0651,0336}
1977/02/14 New 5P7307 Engine Turning Tool Group Fits All Engines{0611}
1977/02/14 Correct Use Of Plugs In Drain Holes Of Hydraulic Pumps That Have Two Seals On The Shaft-Use A Plug In Drain Hole Except With Water Glycol Systems{5055,5073}
1977/01/31 Low Emission Truck Engines With Exhaust Gas Recirculation (EGR) Systems{1050}
1977/01/31 Transportation Notice Plate Is No Longer Needed For Pressurized Nitrogen Cylinders{7557}
1977/01/31 New Remote Control Switch Assembly For Electric Hydraulic Pumps{0621,0623}
1977/01/31 Improved Crankshaft Main Bearing With Higher Strength Aluminum Alloy{1203}
1977/02/28 Changes To Retainer Nut Torque And Assembly Procedures For Turbocharger Compressor Wheels{0374,1052}
1977/03/07 Relief Valve Added To Lubrication And Testing Group For Sealed And Lubricated Track{0651,0671,4175}
1977/03/07 Improved Shut-Off Solenoids For Engines Equipped With Sleeve Metering Fuel Systems{1259}
1977/03/07 Drains In New Fuel Injection Pump Housing And Governor Housing Prevent Possible Corrosion And Freezing Damage{1286}
1977/03/07 Use Insert To Repair Bearing Seat In Water Pump Housing{1361}
1977/03/07 Cooling System Orifice Changed For Better Flow Control And Air Removal{1380}
1977/03/21 New Spring Used In Fuel Ratio Control{1278}
1977/04/11 New Retainer And Improved Housing Keep Water Pump Bearing Tight; Repair For Loosened Bearing{1361}
1977/04/11 Improved Mounting For Expansion Tank{1354,1379,1380}
1977/04/11 New Shaft Assemblies Used For Forward And Reverse Clutch And Stronger Nipple Used At Oil Pump{3302,3306,3307,3310,3314}
1977/04/11 New Diaphragm Used In Brakesaver Control Valve{1159}
1977/04/18 Tools To Remove Wear Sleeves From Crankshafts{0621,7558}