712MT OWNER’S MANUAL REVISED 3/4/22 Page 12 of 15
MICRO TRENCHER TROUBLESHOOTING GUIDE
CAUTION!!
Always use extreme care when troubleshooting or making adjustments on trencher.
Stay clear of chain and auger when engine is running. Stop engine before disassembling any
component.
A. Entire hydraulic system does not operate and the engine is not under load.
1.
Low hydraulic fluid in tank.
2.
Hydraulic pump-to-engine coupler has
slipped.
3.
Main pump suction is leaking air into
pump intake.
Add hydraulic fluid until it is visible in the
sight gauge.
Check for wear and replace both coupler
halves and rubber spider as needed.
Check main suction hoses and fittings for
leaks and tighten fitting nuts.
B. Engine lugs down or dies, but tires and chain are not turning.
1.
Rocks or other obstructions are stopping
the chain.
2.
Trenching depth or speed too great for soil
conditions.
3.
Engine improperly tuned or maintained.
4.
Low oil alert causes engine to shut down.
5.
Engine losing power due to wear.
Reverse chain momentarily to free it from the
obstruction. Raise boom and stop chain. See if
obstruction can be removed from trench.
Adjust unloader valve setting. See illustration
on page 12
See engine manual and correct as needed.
This may occur when trenching on hills.
Level the trencher, check the oil and allow oil
alert to reset.
See engine manual.
C. Chain fails to rotate, but wheel drive works.
1.
Relief valve is stuck or broken.
2.
Chain motor is worn.
3.
Chain drive pump is worn.
Check relief valve. It may need to be serviced
or replaced.
Rebuild or replace motor. New motors are
available from Barreto Manufacturing.
Replace pump. New pumps are available from
Barreto Manufacturing.
