712MT OWNER’S MANUAL REVISED 3/4/22 Page 13 of 15
MICRO TRENCHER TROUBLESHOOTING GUIDE (continued)
D. Wheels fail to turn, but chain is rotating.
1.
Hubs are unlocked (most common).
2.
Sprocket key is sheared
3.
Wheel Drive Unloader Valve not properly
adjusted
4.
Wheel Control Valve not completely
activated
Lock the hubs
Replace key and other parts as needed.
See illustration on page 12.
Wheel Control Valve must be in
REVERSE position. Adjust wheel
drive on/off lever so valve spool is at
full stroke when lever is pulled.
E. Hydraulic fluid leaks in hydraulic system.
1.
Fittings are loose
2.
Worn or broken hoses
3.
Hydraulic fluid around chain motor or shaft.
Tighten fittings on hoses and adapters
Replace damaged hoses
Inspect motor for leaking shaft seal.
Rebuild or replace motor.
F. Foaming hydraulic fluid coming from breather hose.
1.
Air leaking into fluid (most common).
2.
Improper fluid used for climate.
Inspect and tighten fittings and clamps
on the pump intake hoses.
Verify that hydraulic fluid used had
antifoaming additives. Tractor
transmission/hydraulic fluid ISO 68 is
recommended for use in temperatures
above +32°F.
G. Boom does not lift, or does not lower into ground.
1.
Rock or debris is jammed in lift
mechanism.
2.
Boom pivot bushing seized.
Remove obstruction and inspect
machine for damage.
Disassemble, inspect, clean and replace
parts as required.
