Case IH 12525 – Vehicle Control Unit (VCU) or ABS/Brake Control Module: Left AoH stroke too long during single braking

The brake actuator or pedal is traveling further than its specified mechanical limit before building sufficient braking pressure during independent left brake application.

• Case IH Puma Series (170, 185, 200, 215, 230, and CVX variants)
• Case IH Maxxum Series (120, 125, 130, 140, 155)
• Case IH Vestrum Series

1. 1

   Check for air in the brake circuit (the most common cause of excessive stroke) and bleed if necessary.

2. 2

   Inspect for fluid leaks from the hydraulic control pipes, hub seals, piston seals, or delivery unions.

3. 3

   Test the electrical continuity of the End of Stroke Switch (Rear Left, S-085) on the AoH converter to ensure the sensor hasn't failed or shorted.

4. 4

   Inspect the brake control pumps (master cylinders) for internal wear, which can cause pressure bypass.

5. 5

   Verify tire pressures are correct, as incorrect pressure can cause unbalanced braking symptoms.

1. 1

   Park and secure tractor

   Park the tractor on a level surface, turn off the engine, and engage the parking brake.

2. 2

   Disconnect battery

   Disconnect the negative battery cable before beginning work.

3. 3

   Access AoH converter

   If accessing the main front AoH converter unit, safely lift the tractor and remove the front wheels (Prior operation: 44.511) using adequate lifting equipment.

4. 4

   Replace Brake Control Pump

   Disconnect the control pipes, the fluid tank hoses, and the pressure sensor connections. Unbolt and remove the worn pump body. Fit the new pump, secure it, and connect it to the control pedals. Reconnect all control pipes and sensor connections.

5. 5

   Reconnect battery

   Reconnect the negative battery cable.

6. 6

   Bleed brake circuit

   Bleed the air from the hydraulic service brake circuit completely, as any remaining air will immediately trigger the 'stroke too long' fault again.