1982/04/12 Caterpillar

New Spring Used In Accumulator Charging Valve Group For Brakes{4264}

Usage:

824, 824B, 834 Tr;
825B, 826B, 835 Compactors

SUPPLEMENT: 05/10/82

SERVICE MAGAZINE, APRIL 12, 1982, PAGE 4. In the article, "New Spring Used In Accumulator Charging Valve Group For Brakes," on page 4, change the subtitle to: "992, 992B, 992C, 988, 988B Loaders; 824, 824B, 834 Tractors; 825B, 826B, 835 Compactors."

--------------- END SUPPLEMENT ---------------

Description of Change: A new spring is used in the accumulator charging valve group for the brakes on the above machines. The new spring has a higher force at its assembled length. For this reason, less shims are needed with the spring to get the correct charging range.

With the former spring, more shims were needed. The use of more shims put too much compression on the spring. This limited the movement of the charging spool so that it did not move completely to the detent position. The result was a decreased pressure range that caused the system to make more charging cycles than were necessary.

Adaptable As: The new 4T2541 Spring is a direct replacement for the former 4J6808 Spring in the 4J4984, 5J2166, 7J2589 and 9J4693 Accumulator Charging Valve Groups. The 4J6808 Spring is still available for use in other applications.

Caterpillar Information System:

1982/04/12 Lock Screw For Threaded Crown On Hydraulic Cylinders No Longer Used{5000}

1982/04/12 Use Correct Part Numbers For Main And Connecting Rod Bearings{1230,1203,1219}

1982/04/12 New Clearance Specification Used In Torque Converter{3101}

1982/04/05 New Outer Duo-Cone Seal Groups Used In Service And Parking Brake Groups{4208,4251,4267}

1982/04/05 Lubricant Recommendations Have Been Changed For Vehicular Products{0680,0374,0375,3004,1318,5060}

1982/04/05 Use FT1631 Flare Nut Wrench For Connector In Bulldozer Lift Circuit{0610,0611,0623}

1982/03/29 Twisted Port Plate Can Cause Excessive Case Drain From Piston Pump Or Motor{5058,5070}

1982/03/29 Increased Clearance Between Hoist Cylinder Assembly And Rod{5102,7258}

1982/03/29 Multi-Piece Wheel Rims; Caution Must Be Used{4202,4201}

1982/03/29 FT1667 And FT1668 Beam Assemblies For Undercarriage Removal{0642,0643,4150}

1982/03/29 Location Of Sending Unit Changed To Improve Accuracy Of Water Temperature Indication{7453}

1982/03/29 Parts Book Changes{0374}

1982/04/12 Make Sure Hydraulic Pumps Are Installed Correctly{5055,5070,5073}

1982/04/12 Use Correct Size Bolt To Install 5P9736, 6V2156 Or 6V2157 Link Brackets{0644}

1982/04/12 Correct Position Of Shims In Blade Lift And Centershift Cylinder Groups{5102,5223}

1982/04/12 Use 6V4938 Seal Guide For Seal Installation On Hydraulic Cylinder Rod{0622,5458}

1982/04/12 Add Lubricant For Motor Shaft Bearing{5058,5200}

1982/04/19 New Brackets Used In Front Floodlamp Lighting Group{7309}

1982/04/19 Improvements Made To 6V3000 Sure Seal Repair Kit{0611,1408}

1982/04/19 New Relief Valve For Steering System Is Easier To Adjust{4322}

1982/04/19 New Broken Link Spring Used In Governor{1264}

1982/04/19 New Seal In Transfer Gear Group{3176,3159}

1982/04/26 Check Valve Prevents Release Of The Parking Brake{5220,4267}

1982/04/26 External Reinforcements Can Be Added To Main Frames{7051}