Case IH 152 – TRANS: Front Suspension pressure control not able to increase pressure on the rod side.

The front axle suspension system uses a level control valve block equipped with PWM solenoid valves and pressure sensors to actively manage the ride height and cushioning of the front axle. When the controller commands the rod-side solenoid valve to open and increase hydraulic pressure on the rod side of the suspension cylinders, the rod-side pressure sensor (DA-R) fails to detect the expected pressure increase. This usually points to a failed pressure sensor reading incorrectly, a blown-out valve orifice, a stuck solenoid valve, or a wiring issue.

• MX Magnum
• Magnum 215
• Magnum 225
• Magnum 235
• Magnum 245
• Magnum 250
• Magnum 260
• Magnum 275
• Magnum 280
• Magnum 290
• Magnum 305
• Magnum 310
• Magnum 315
• Magnum 335
• Magnum 340
• Puma 170
• Puma 185
• Puma 200
• Puma 215
• Puma 230
• Puma 180-260 CVX
• Steiger
• Maxxum

1. 1

   Check Sensor Baseline Pressure: Using the Case IH Electronic Service Tool (EST) or the tractor's A-post display (navigate to the Trans FSUS view pressure page), monitor the rod and piston pressures.

2. 2

   Depressurize and Verify: Manually relieve the hydraulic pressure in the suspension system by tightening down the manual relief thumb screws. With the system completely depressurized, both the rod and piston pressure sensors should read below 40 psi (approx. 30 kPa). If the rod-side sensor still shows a high reading at zero pressure, the sensor has internally failed.

3. 3

   Inspect Valve Orifices: If the sensor reads correctly at zero pressure, the issue is likely mechanical. Check the internal brass orifices in the suspension valves, as it is highly common for these to back out and destroy themselves under pressure.

4. 4

   Electrical Testing: Check the wiring harness leading to the rod-side pressure sensor and the rod-side PWM solenoid for continuity, shorts to ground, or damaged pins.

1. 1

   Depressurize the System

   Locate the suspension level control block (often mounted on top of the rear axle housing or near the front suspension manifold). Locate the adjusting thumb screws on the solenoid valves and screw them in to manually release the oil back to the tank. You must depressurize the piston side and the rod side individually.

2. 2

   Replace the Pressure Sensor

   If the sensor has failed, disconnect the electrical connector from the rod-side pressure sensor (DA-R). Unscrew the sensor from the control block. Install the new sensor and torque to OEM specifications, then reconnect the harness.

3. 3

   Inspect and Replace Orifices

   If the sensor is good, remove the hydraulic lines attached to the front side of the suspension valve block. Look inside the ports to inspect the brass orifices. If they are missing, backed out, or chewed up, extract the debris and install new brass orifices. Reinstall the hydraulic lines.

4. 4

   Replace the Solenoid Valve

   If the sensor and orifices are intact, the rod-side PWM solenoid valve cartridge is likely stuck closed. Remove the retaining nut, slide off the electromagnetic coil, and unscrew the valve cartridge. Install a new cartridge and reinstall the coil.

5. 5

   Restore System and Calibrate

   Back out the manual relief thumb screws to close the manual release circuit. Start the tractor to allow the hydraulic priority valve to build system pressure.

6. 6

   Run Calibration

   Initiate the front suspension calibration procedure via the tractor's display or the EST to ensure the TRANS controller can successfully raise and lower the rod and piston sides.