1994/07/08 Caterpillar

Improved Master Cylinder Available{4258,4259,5470}


RT50, RTC60 (4XG524-Up, 5PF694-Up) RT50 SA (8DJ496-Up) RT60 (5DG357-Up) Telescopic Material Handlers

SPECIAL NOTE: The RT60 (5DG357-Up) will have a hydraulic boosted brake system installed at production. With the hydraulic boosted brakes, the inching function is lost. Earlier production RT60's can be retrofitted with either the large capacity master cylinder or the boosted system. The retrofit of the boosted system will be explained in a separate article.

A larger capacity master cylinder is being installed at production on the above models. The new 6R-9050 Master Cylinder provides improved pedal feel and eliminates brake pedal bottoming. This master cylinder can be retrofitted to older lift trucks. See Chart for usage.

There are two different retrofit kits in the parts system. See Illustration 1 and 2 and the following charts for usage.

Illustration1. 8Q-2451 Kit. Reference parts: (A) Existing hole. (B) New hole. (C) 985525 Mounting bracket. (D) 897768 Brake Tube As. (bend to suit). (E) Boot & Actuation Rod (supplied with 6R-9050 Master Cylinder). (F) 909613 Yoke.

Installation: 8Q-2451 Kit

1. Move the truck to level ground. Retract the boom completely and rest the carriage on the ground.

2. Shift the direction control lever to neutral, engage the parking brake and turn the ignition switch to OFF. "Tag" the machine that the brakes are inoperative.

3. Raise the dash board up and prop open.

4. Remove the 909613 Yoke (F) from the existing master cylinder and save.

5. Remove the 897768 Pipe (H) from the 5P-4536 Elbow (G) on the master cylinder and push it aside.

6. Remove the 897768 Brake Pipe (D) and push it aside.

7. Remove the two 8T-4178 Bolts (2), two 8T-4121 Washers and the two 6V7744 Nyloc Nuts (3). Set these aside for reassembly.

8. Remove the 975139 Master Cylinder.

9. Drill a new 11 mm (.43 in.) hole as shown in Illustration 1.

10. Install the 6r-9050 Master Cylinder using the 5M-3062 Bolt in hole "A" and one each of the 8T-4178 Bolts, 8T-4121 Washers and 6V-7744 Nyloc Nuts that were set aside.

11. Connect the 897768 Brake Pipe (D).

12. Connect the 897699 Pipe (H).

13. Attach the 909613 Yoke (F) to the master cylinder actuation rod (E).

14. NOTE: DO NO USE BRAKE FLUID. Fill the master cylinder with 10W transmission oil. Bleed the brake system throughly.

15. Adjust the brake linkage and the actuation rod.

16. Test the operation of the brakes and check for leaks.

Illustration 2. 5I-0268 Kit. Reference parts: (A) New hole. (B) Existing hole. (C) 844272 Plate As. (D) Boot & Actuation Rod supplied with 6R-9050 Master Cylinder. (E) 909613 Yoke.

Installation: 5I-0268 Kit

Same as the 8Q-2451 Kit except for the following steps:

6. Remove the 6R-7823 Hose (6) or the 6R-9216 Pipe (6) from the master cylinder and push the hose or pipe aside.

7. Connect the 6R7823 Hose (6) or the 6R9216 Pipe (6) to the 6R-9050 Master Cylinder (1).

Caterpillar Information System:

1994/07/08 Brake System Servicing{4005}
1994/07/08 Avoid Damage to Boom and Attachment Control{5700}
1994/07/08 Alternator Circuit Breaker May Have An Intermittent Fault{1420}
1994/07/08 Improved Mounting Method For Hydraulic Quick Hitch Pins{5133}
1994/07/08 Ensure Brake Hose Is Clear Of Engine Oil Pan{4257}
1992/06/01 Improved Joystick Available For The RT80/RT100 Telescopic Material Handler{5700}
1992/06/01 Rolling Hose Pulley Modification Improves Hose Retention{6460}
1991/12/01 Checking The 838440 Joystick Group{5485}
1991/12/01 Service Parts Available for 838440 Joystick Controller Group. Procedure to Recalibrate the Joystick{5485}
1991/12/01 RT80/RT100 Gearbox Lubrication{3000}
1991/12/01 Test Harness For Calibrating 838141 Electronic Control Box{5485}
1991/11/01 Parts Book Correction{5725}
1994/07/08 New Retrofit Kit Available For Brake Pipe Arrangement{4257}
1994/07/08 Improved Transmission Oil Filler Tube Mounting{3014}
1994/07/08 Transmission Drive Shaft Group Replacement{3253}
1994/07/08 Extended Shuttle Valve Holder{4289}
1994/07/08 Improved Lubrication Of Attachment Coupler Bushing{5133}
1979/01/10 Check The Adjustment Of The Original Tachometer Before A New Tachometer Is Installed
1979/01/10 New 6V87 Gauge Measures Valve Stem Wear
1979/01/10 Caution: Do Not Change Orifice In Water Outlet Of Auxiliary Pump Group
1979/01/24 A New 6V29 Sleeve Metering Fuel System Pump Roll Pin Tool Is Used To Adjust And Make A Replacement Of Roll Pins In The Fuel Injection Pump Housing
1979/01/24 Ether Starting Aid Groups Are Now Available
1979/01/24 Current Chart For Dynamometer Adapters
1979/01/24 5P9705 Tapered Rod Tool Group Used For Removal And Installation Of Piston Pin Bearings In Tapered Connecting Rods
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