1967-72 GMC/Chevrolet Truck HydroBoost Instructions
This system is intended for “off road use only”
1. Please carefully inspect the entire braking system thoroughly, and replace any marginal items. Installation of braided steel, high performance brake lines is highly recommended, though not mandatory.
2. Please carefully inspect the entire power steering system thoroughly, and replace any marginal items. This system will not function properly unless the power steering system is 100%
3. Disconnect the battery.
4. Disconnect the brake pedal rod connection at the brake pedal.
5. Disconnect the master cylinder from its mounting, and secure it approximately 6 inches forward (if brake line integrity / routing permits – otherwise remove the master cylinder).
6. If equipped with factory power brakes, remove the power brake booster to firewall attachment nuts, then carefully remove the brake booster from vehicle, (you may have to gently pry the unit loose of the firewall), remove the rubber firewall boot also.
7. Assemble the brake pedal rod adapter onto the hydraulic assist unit’s threaded pedal rod, and apply a small amount of grease to the brake pedal rod eyelet of hydraulic assist unit.
8. Install the hydraulic brake booster carefully into the firewall, with the hydraulic fittings facing downward, accumulator to the driver’s side, while aligning brake pedal / pedal rod interface as required.
9. Using the 4 supplied attachment nuts and washers, securely fasten the hydraulic assist unit to firewall.
10. (Bench bleed master cylinder if removed from vehicle in prior steps / or replaced), then connect the master cylinder to the hydraulic brake assist unit firmly, using the supplied chromed replacement nuts.
11. Adjust the pedal height to the stock height / your liking, by spinning the threaded assist unit pedal rod in / out of the pedal rod adapter – 10 threads minimum engagement.
12. Double check for appropriate thread engagement at pedal rod adapter, (10 threads absolute minimum) then tighten the brake pedal rod jam nut. (Do not overtorque!)
13. Connect the pedal rod to brake pedal securely.
14. Remove the existing high side power steering line, allowing the system to drain into a suitable container.
15. Connect the shorter pressure line direct fit 3/8 flare style 90 degree hose end to the power steering pump, and then connect the other end of this line to the inlet/driver’s side AN style fitting of the hydraulic assist unit.
16. Install the supplied AN-6 line adapter into the steering box pressure inlet port.
17. Connect the longer pressure line, 90 degree AN-6 female hose end, to the steering box AN adapter, then connect the other end (direct fit 3/8 flare style 90 degree hose end) to the outlet / passenger side port of the hydraulic assist unit.
18. Inspect the existing power steering low pressure return line, from steering box to ps pump, replace if marginal.
19. Cut the existing power steering return line approximately 3” - 4” from the ps pump push on hose nipple, install the brass “T” STRAIGHT INLINE using the supplied hose clamps.
20. Connect the chromed hose nut end of the return line to the hose fitting on the assist unit, then run the hose from the brake assist unit hose nipple to the remaining brass “T” perpendicular nipple – trim hose to length as necessary and clamp to the “T” securely.
Get pdf 1967-72 GMC/Chevrolet Truck HydroBoost Instructions
