Case IH 12687 – Trailer Brake Control Module (TEBS) or Suspension/Cab Control ECU: Pneumatic output - delivery port - rear right - leakage (e.g. while trying to hold pressure)

This fault indicates that the system has detected an air pressure loss at the rear right pneumatic delivery port. The system is attempting to hold a specific air pressure (either for trailer air brakes or pneumatic cab/axle suspension) but is registering a continuous drop in pressure, meaning air is escaping faster than the compressor or reservoir can supply it.

• Puma
• Magnum
• Steiger

1. 1

   Perform an audible and visual inspection for air leaks at the rear right delivery port using an ultrasonic leak detector or soapy water solution.

2. 2

   Conduct pressure testing by connecting a 0-150 PSI gauge to the delivery port and commanding the system to apply pressure to verify if it holds steady.

3. 3

   Inspect the valve body and port threads for cracks or failed pipe thread sealant.

4. 4

   Perform an internal leakage test by checking the exhaust port with the system pressurized but the port closed/released to identify worn internal seals or a scored valve bore.

1. 1

   Depressurize the System

   Safely drain all air from the pneumatic reservoirs to prevent injury before disconnecting any lines.

2. 2

   Clean the Area

   Thoroughly clean the rear right delivery port and surrounding valve block to prevent dirt from entering the pneumatic system during disassembly.

3. 3

   Remove the Leaking Component

   Disconnect the pneumatic lines from the delivery port. If the leak is at the fitting, remove the fitting. If the valve housing is cracked or internal seals have failed, remove the entire valve assembly.

4. 4

   Inspect and Replace

   If the housing is cracked, the valve cannot be repaired and must be replaced. If the leak is due to failed thread sealant, clean the threads, apply new pneumatic-grade thread sealant, and reinstall.

5. 5

   Reassembly

   Install the new valve or fitting. Reconnect the pneumatic lines, ensuring they are seated correctly and not kinked.

6. 6

   System Test

   Start the tractor, allow the air compressor to build full system pressure, and repeat the soapy water test on the repaired area to verify the leak is resolved. Clear the fault code using a Case IH Electronic Service Tool (EST).