Takeuchi TB215R Workshop Manual

TROUBLESHOOTING
BOOM
6
5
BOOM 5G0AX001
When the control lever is pulled slowly, the boom drops temporarily.
1. Check the load check valve in the control valve.
a. Disconnect the control valve end of the hose con-
necting the control valve and the boom cylinder
together.
b. Connect the disconnected hose to the arm or
bucket block.
c. Operate the boom cylinder.
If the boom cylinder operates normally, it indi-
cates that the load check valve is faulty.
Before performing steps a to c above, set the ma-
chine posture as follows.
• Fully extend the bucket cylinder, fully retract the
arm cylinder, and rest the bucket on the ground.
When the spool first starts to pull, the oil pressure is
low and the flow rate is low. If the load check valve is
faulty, the oil will temporarily flow backward due to
the load applied to the boom cylinder. As a result, the
boom temporarily drops.
2. Check for leakage inside the boom cylinder.
If the oil flows from the head side (A) to the rod side
(B) due to a faulty boom cylinder piston or tube, the
boom temporarily drops because of the low oil pres-
sure and small flow rate when the spool first starts to
pull. Also, the cylinder will have insufficient drive
force. However, the amount of spontaneous drop will
also be large in this case.
• Check the cylinder.
“Boom cylinder is slow or lacks force, 5. Check
for boom cylinder.”
1
Check the load check
valve in the control valve.
Faulty
Repair or replace the housing
block.
Normal
2
Check for leakage inside
the boom cylinder.
Faulty
Repair or replace the boom
cylinder.

Takeuchi TB215R Specifications

General

Brand	Takeuchi
Model	TB215R
Category	Excavators
Language	English