Technical Bulletin. Parts and Service News

Transcription

1 Equipment Affected: Part Number Affected: Technical Bulletin Tractors with Hydro-Vac Brakes Part Description, HYDRO-VAC (VACUUM BOOSTER). Discrepancy, The vacuum booster may not provide enough brake pressure on single-caliper brake systems. Possible failure With certain engine and differential combinations, single-caliper brakes may not prevent the tractor from moving with the engine idling, the transmission in forward, and the parking brake released. Parts shipped with bulletin Part Number Description Qty Hydro Boost/Master Cyl Assy-HD Hose Kit, Hydro Boost Bracket, Relief Valve C24 Bolt, 3/8-16 X 1½ Brake Line Front Master Cyl Brake Line Out, Control Value 1 TB T Technical Bulletin 1 TB Page 1 of 7

2 Kit Contents Refer to the parts shown below. The numbers indicate the steps in which each part is used Kit Contents, except Hydro Boost Assembly and Bolts 13 Page 2 of 7

3 Installation Procedures. 1. Remove the left side hood panel Disconnect the Hydraulic Lines between the hydraulic pump and the power steering unit. 3. Disconnect the brake fluid lines from the master cylinder. 4. Disconnect the Hydro-Vac actuator from the brake pedal bell-crank clevis. Discard the clevis bushing. The kit contains a replacement. 5. Remove the Hydro-Vac/Master Cylinder assembly. You will re-use 2 of the 3/8-16 X 1¼ bolts and all of the nuts and lock washers. Page 3 of 7

4 6 Hydro Boost/ Master Cylinder Assembly 6. Install the Pressure Relief Valve bracket and Hydro Boost/Master Cylinder Assembly on the same mounting plate as shown. Use the two 3/8-16 X 1½ bolts in the top holes Attach the brake actuator to the brake pedal bell-crank clevis using the bushing provided with the Hydro Boost assembly and install new cotter key. Page 4 of 7

5 NPT 8. Remove the Pressure Relief Valve from its original location.. Wrap the NTP threads of the two kit-provided tees with Teflon tape and install the tees as shown. Return 10 Pressure 10. Bolt the Pressure Relief Valve to the to the Relief Valve Bracket as shown. Page 5 of 7

6 3 11. Assemble a return hose and push-lock tee as shown above Flow Install the brake fitting tee and brake light switch in the rear port of the master cylinder. (This was on the front port.) 13. Connect the rear brake line to the brake fitting tee and brake light switch. 14. Connect the U-shaped kit-supplied brake line from to the front master cylinder port as shown. 15. Connect the pressure control valve and its adapter fittings to the brake line from the front master cylinder port. Important! The Flow arrow on pressure control valve must point towards the brakes. 16. Connect the second kit-supplied brake fluid line from the pressure control valve to the tee as shown. Page 6 of 7

7 Connect the return hose assembled in step 11 to the base of the fluid return tee. 18. Connect a hydraulic pressure hose from the hydraulic pump pressure side to the tee fitting on the pressure side of the pressure relief valve. 1. Connect a hydraulic pressure hose from the tee fitting on the pressure side of the pressure relief valve to the high-pressure nipple of the Hydro-Boost unit. 20. Connect a hydraulic pressure hose from the high-pressure out nipple on the Hydro-Boost unit to the fluid supply nipple of the steering gearbox. 21. Connect a hydraulic return hose from the fluid return nipple of the steering gearbox to the push-lock Tee fitting. Fasten it with a hose clamp. 22. Connect a push-lock hydraulic line from the fluid return nipple of the Hydro-Boost unit to the push-lock tee fitting. Fasten both ends with hose clamps. 23. Connect a hydraulic return hose from the tee fitting on the return side of the pressure relief valve to the reservoir. Fasten it with a hose clamp. 24. Fill the master cylinder with brake fluid that meets MIL-B-466A specifications and bleed the brakes. If you have a pressure bleeder, follow the instructions for that equipment. To bleed brakes manually, see the attachment. Warning Brake operations must be fully tested after completing the bleeding procedure. Do not use any vehicle that does not have properly functioning brakes. Time Required For Completion 2 Hours Page 7 of 7