Applicable Systems
3CX Backhoe
Symptoms
Travel on both tracks stops; other functions work normally.
Possible Causes
- Travel pressure cut-off solenoid failed open (no signal).
- Final drive cross-over relief valve stuck open.
- Travel pump swashplate stuck at zero angle.
Troubleshooting Steps
- Step 1: Check travel solenoid LED on valve bank with key-on.
LED illuminates when travel lever moved; solenoid clicks. - Step 2: Measure travel pump control pressure.
Control pressure 2.8 MPa at travel command; swashplate moves. - Step 3: Inspect final drive oil for metal particles.
Oil normal color; no bronze or steel chips in drain sample.
How to Reset
Replace travel solenoid or pump; replace crossover relief valve if stuck.
Common Replacement Parts
- Travel Solenoid 332/D1183: Travel Solenoid 332/D1183
- Travel Pump 20/950631: Travel Pump 20/950631
Frequently Asked Questions
- Q: Can I tow the machine with dead travel?
Only short distances at < 3 km/h to avoid motor damage.
- Q: What cuts off travel pressure?
Solenoid opens signal line to pilot stage; no signal = no travel.
Source: JCB JS220 Hydraulic Manual
Category: Heavy Equipment