BEARING AS 1127317 - Caterpillar

If the jump is within limits, but the jump is still objectionable, the customer may choose "Standard 1-Valve" configuration. "Standard 1-Valve" configuration effectively keeps the balance spool active at all times. If the jump is outside the specified limits, the following steps will help determine the root cause.Note: One preliminary item to eliminate is whether the bang occurs only when the ride control becomes active, or while the ride control is already active. If the bang occurs when going over bumps with the ride control active, the accumulator piston is hitting the stop. This issue could indicate excessive accumulator precharge if the bang occurs with an empty bucket when the boom travels up. This issue could indicate insufficient accumulator precharge if the bang occurs with a loaded bucket and the boom is traveling down.Note: All references to Left Hand or Right Hand locations are viewed from the position of the operator.
Illustration 1 g03353431
Ride Control Group (1) Ride Control On/Off Solenoid (2) Ride Control Rod End Solenoid (3) Ride Control Head End Solenoid (4) Balance Spool
Increase the "Ride Control Pressure Equalization Time" in ET. Increase the settings in increments of 3 to 5 seconds, and observe the response. You may need to set the equalization time to 20 seconds or more to eliminate the jump.
If the jump gradually decreases as the equalization time is increased, the Balance Spool may be faulty. Refer to Step 13.f below.
If increasing the equalization time has no effect, the Ride Control On/Off Solenoid Valve may be defective. Refer to Step 13.g below.
Normally if the ride control is working properly, the jump will be minimal and will not change with the equalization times beyond 3 seconds.
Adjust the accumulator precharge nitrogen pressure higher and/or lower as necessary. If the lift arms appear to react normally when the ride control is activated, the bang could be coming from the ride control accumulator. The accumulator piston could be hitting the stops. If the precharge pressure is too high, the piston could hit the stop with an empty bucket. If the precharge pressure is too low, the piston could hit the opposite stop with a full load. Also, the piston, seals, or accumulator bore is possibly worn. Hook a gauge into the accumulator oil line to observe the resulting pressure when ride control activates or when traveling over bumps.Note: The accumulator precharge may need adjusted based on bucket mass.
With the ride control configuration in "Improved 2-Valve" configuration, check to make sure that all three ride control solenoids are shifting properly. Ride Control On/Off Solenoid (1) should turn "OFF" when the ride control activates. After the equalization time, Ride Control Rod End Solenoid (2) and Ride Control Head End Solenoid (3) should turn on. If the solenoids do not activate in the proper sequence, you will need to determine the cause.Note: This step verifies that the electrical signal to the solenoids is operating correctly. This step does not determine if the spools are sticking, or if the ports are plugged.
Select "Standard