DRESSTA TD-25M EXTRA, Service Manual

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HYDRAULICS
SECTION 10
Page 9
DRESSTA TD-25M EXTRA
GENERAL
4. SERVICE DIAGNOSIS
This portion has been prepared to serve as a guide in locating the source of problems that may be
encountered with hydraulic assy. In diagnosing problems it should be remembered that it is
possible for a given symptom to be caused by any one of a number of deficiencies. It is also
possible for a given deficiency to cause any one or more of various symptoms.
The following chart gives predominant symptoms and their primary causes, based on our
experiences. When a number of possible causes of a complaint are given, they are listed
in a logical sequence for checking and corrective action.
Tests given in TESTS AND ADJUSTMENTS are used to further pinpoint the problem.
Equipment Hydraulic System
COMPLAINT
PROBABLE CAUSE REMARKS
Noisy Operation, Oil Foaming
1. Low oil level Check level at sight gauge and fill as necessary.
Check for external leaks and tighten or replace
parts as necessary.
2. Oil viscosity too dense Use recommended oil. Refer to OPERATOR'S
MANUAL.
3. Dirty oil strainer in reservoir Clean.
4. Dirty reservoir pressure/vacuum relief valve Clean.
5. Air leakage into hydraulic suction lines
Apply shave cream to all suction connections, and
tighten where cream disappears.
Blade Lift Cylinder Drops
1. Faulty one of blade lift circuit assembly Refer to Paragraph 6, BLADE LIFT CYLINDER
DRIFT TEST.
Ripper Lift Cylinders Drops
1. Faulty one of ripper lift circuit assembly Refer to Paragraph 7, BLADE LIFT CYLINDER and
RIPPER LIFT CYLINDER DRIFT TEST
Blade Tilt Circuit or Blade Tilt/Pitch Circuit Weak or Slow
1. Internal leak in tilt or tilt/ pitch cylinder Refer to Par. 9, PISTON PACKING TEST.
2. Internal leak in tilt control relief valve Refer to Par. 5, RELIEF VALVE PRESSURE TEST.
3. Middle (blade tilt) section pump worn out Refer to SECTION 10A, PUMPS.
Blade Lift and Ripper Cylinders Weak and/or Slow Movement
1. Internal leak in main control relief valve Refer to Par. 5, RELIEF VALVE PRESSURE TEST.
2. Front section pump worn out Refer to SECTION 10A, PUMPS.
All Cylinders No or Slow Movement
1. Insufficient oil supply Refer to Noisy Operation Oil Foaming.
2. Pilot supply valve out of order Refer to SECTION 10B, PILOT PRESSURE
VALVE.
3. Rear pilot pump worn out Refer to SECTION 10A, PUMPS.