2010 Hino 268 - Brake Pedal Soft / P3001 Code

Question

Working on a 2010 Hino 268 box truck. The driver complained the brake pedal went almost to the floor suddenly. The dash has an ABS light and a 'Brake' warning light with code P3001.

I checked for leaks at the wheels and along the frame rails but everything is bone dry. The master cylinder reservoir is full. When I pump the brakes, I get some pressure, but it fades away quickly. This truck has the air-over-hydraulic system. Could it be the power brake booster or the master cylinder internally bypassing?

DieselDan_77 · Accepted Answer

✅ Confirmed fix: On these Hinos, the P3001 code often points to the stroke sensor or a discrepancy in the hydraulic booster. In this case, it was the hydraulic brake booster (the power cluster) failing internally. The internal piston seal was bypassing, so the fluid wasn't being pushed to the calipers with full pressure. Replaced the booster assembly and the pedal is firm again.

FleetMech_Ed · Answer

It’s likely your ABS actuator block. If one of the dump valves gets stuck open, you’ll lose pedal pressure to that circuit without seeing an external leak. Try capping off the lines at the ABS module one by one to see which circuit is losing pressure.

2010 Hino 268 - Brake Pedal Soft / P3001 Code

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