Travel and transmission
Why will the excavator not travel forwards or backwards?
Movement in only one direction narrows the fault more than total travel failure. First establish whether this is a tracked excavator with travel motors, a wheeled hydrostatic machine or an F/R gearbox. Each needs a different diagnostic approach.
Direction command
The fault may precede the hydraulics: joystick, pedal, F/R switch, position sensor, wiring, solenoid or controller. If no reverse command is produced, the remaining system may be sound.
Solenoids and control valves
Check the failed direction’s solenoid, supply, resistance to specification, control pressure, switching valve and contamination or sticking. Compare with the working direction.
Hydrostatic drive
Possible causes include swash plate or servo, control valve, pump, hydraulic motor, shuttle valve, internal leakage or brake.
Powershift and gearbox
If forward works but reverse does not, check reverse clutch-pack pressure, solenoid, F/R valve, clutch pack, seals and gearbox mechanics.
Tracked excavator: one side or both?
For one affected track, compare pilot pressure, main flow, centre swivel, motor, travel relief, brake and final drive. The same directional failure on both sides more strongly suggests a common command or control problem.
Do not replace parts without measurements
No reverse can result from electrical, valve, pressure or mechanical faults. Replacing a motor or controller without checking command and pressure often leaves the cause unresolved.
What you can observe
One side or the whole machine? Forward or reverse? Does it try to move, load the engine, show faults or produce solenoid sounds? Did it happen suddenly or gradually?
Related problems
Further service support
Have a fault code?
Problem still there?
If these checks have not identified the cause or the fault returns, contact TSV Servis. The more initial information you provide, the sooner we can identify the next diagnostic direction.
What to send us
Send the machine model, S/N, transmission or hydrostatic type, failed direction, faults and comparison of forward and reverse control and working pressures.
Include the make and model, S/N or a nameplate photo, engine model if known, operating hours, exact code or display photo and when the fault occurs.
Also tell us what you have already checked or replaced and the results. Include a photo or short video of the symptom where useful.
+420 722 307 850 · tsvcz@seznam.cz