- Excavator: Medium Excavators 320C-330C
Introduction
Illustration 1 | g01051135 |
This Special Instruction describes the hydraulic adjustment procedures for excavators that are equipped with the long reach front. The adjusting procedures are necessary to prevent damage to the excavator. The long reach front typically differs from the standard machine in the following areas: counterweight, bucket, boom, stick, lines group, cylinder group and speed control.
Adjustment Procedure
Line Relief Valve
Hydraulic oil pressure can remain in the hydraulic systems after the engine and pump have been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic systems. To prevent possible injury, refer to the section, Testing and Adjusting, "Hydraulic System Pressure - Release" before any fitting, hose or component is loosened, tightened, removed or adjusted.
When possible, the bucket or attachment must always be lowered to the ground before service is started. When it is necessary for the boom to be in the raised position while tests or adjustments are done, be sure that the boom, stick and bucket or attachment have correct support.
The swing lock (if equipped) must be engaged before service is started.
Always move the machine to a location away from the travel of other machines. Be sure that other personnel are not near the machine when the engine is running and tests or adjustments are being made.
Line Relief Valve Pressures     | ||||
Machine     | 320C L     | 322C L     | 325C L     | 330C L     |
Boom Lower     | 37200 ± 1000 kPa (5400 ± 145 psi)     | 37200 ± 1000 kPa (5400 ± 145 psi)     |
36750 ± 1450 kPa (5300 ± 210 psi)     |
18633 ± 981 kPa (2700 ± 140 psi)     |
Boom Raise     | 37200 ± 1000 kPa (5400 ± 145 psi)     |
37200 ± 1000 kPa (5400 ± 145 psi)     |
36750 ± 1450 kPa (5300 ± 210 psi)     |
36750 ± 1450 kPa (5300 ± 210 psi)     |
Stick Out     | 37200 ± 1000 kPa (5400 ± 145 psi)     |
37200 ± 1000 kPa (5400 ± 145 psi)     |
36750 ± 1450 kPa (5300 ± 210 psi)     |
36750 ± 1450 kPa (5300 ± 210 psi)     |
Stick In     | 22555 ± 985 kPa (3300 ± 140 psi)     |
22550 ± 950 kPa (3300 ± 140 psi)     |
22550 ± 950 kPa (3200 ± 140 psi)     |
26871 ± 981 kPa (3900 ± 140 psi)     |
Bucket Close     | 19120 ± 980 kPa (2800 ± 140 psi)     |
19120 ± 980 kPa (2800 ± 140 psi)     |
19120 ± 980 kPa (2700 ± 140 psi)     |
13827 ± 980 kPa (2000 ± 140 psi)     |
Bucket Open     | 19120 ± 980 kPa (2800 ± 140 psi)     |
19120 ± 980 kPa (2800 ± 140 psi)     |
19120 ± 980 kPa (2700 ± 100 psi)     |
13827 ± 980 kPa (2000 ± 140 psi)     |
- Place the machine on a level surface.
- Start the engine and warm the hydraulic oil to a temperature of 55° ± 5°C (131° ± 9°F).
- Adjust the line relief valves for the bucket cylinder. Set the line relief valves for the head end and the rod end of the bucket cylinder at the correct pressure. Refer to table 1 for the correct pressure for your machine. Refer to Testing and Adjusting, "Line Relief Valve - Test and Adjust" for the adjustment procedure.
- Adjust the line relief valve for the head end of the stick cylinder. Set the line relief valve for your machine to the specified pressure. Refer to table 1 for more details about your machine. Refer to Testing and Adjusting, "Line Relief Valve - Test and Adjust" for the adjustment procedure.
- Adjust the line relief valve for the rod end of the boom cylinder. Set the pressure for your machine according to table 1.
- See the adjustment procedure that is offered by Young Corporation.
Adjustment Procedures
Cylinder Speed     | ||||
Machine     | 320C L     | 322C L     | 325C L     | 330C L     |
Boom Lower     | 3.7 ± .3 seconds     | 4.2 ± .3 seconds     | 4.5 ± .5 seconds     | 4.8 ± .5 seconds     |
Boom Raise     | 3.8 ± .3 seconds     | 4.0 ± .3 seconds     | 4.2 ± .5 seconds     | 4.4 ± .5 seconds     |
Stick Out     | 3.4 ± .3 seconds     | 4.0 ± .3 seconds     | 4.6 ± .5 seconds     | 4.9 ± .5 seconds     |
Stick In     | 4.7 ± .3 seconds     | 5.3 ± .3 seconds     | 5.8 ± .5 seconds     | 6.3 ± .5 seconds     |
Bucket Close     | 1.8 ± .3 seconds     | 1.7 ± .3 seconds     | 2.3 ± .5 seconds     | 2.5 ± .5 seconds     |
Bucket Open     | 2.5 ± .3 seconds     | 2.3 ± .3 seconds     | 3.9 ± .5 seconds     | 4.4 ± .5 seconds     |
Boom Lower and Boom Raise
- Place the machine in position (A), as shown. Refer to Illustration 2. The stick cylinder should be completely retracted. The boom cylinder should be completely extended.
Illustration 2 | g00623328 |
(A) The stick cylinder is retracted. The boom cylinder is completely extended. (B) The boom is 2000 mm (78.75 inch) above ground level. |
- Fully activate the boom down control. Measure the boom lower travel time from position (A) to position (B). Refer to Illustration 2. Compare the boom lower travel time to the specifications that are listed in table 2. If the boom lower travel time is not within specifications, proceed to Step 3. Reverse this step in order to measure the boom raise travel time. Measure the boom raise travel time from position (B) to position (A). If the boom raise travel time is not within specifications, proceed to Step 3.
- Adjust the boom speed to the correct specification by using adjustable boom valve (1) which is located near the main control valve. Refer to Illustration 3.
Illustration 3 | g01013103 |
(1) Adjustable boom valve |
Stick In and Stick Out
- Place the machine on a level surface.
- Start the engine and warm the hydraulic oil to a temperature of 55° ± 5°C (131° ± 9°F).
- Raise the boom completely. Retract the stick cylinder completely. Refer to "position A" in Illustration 4.
Illustration 4 | g00623848 |
(A) The stick cylinder is fully retracted. (B) The stick cylinder is fully extended. |
- Fully activate the stick in control. Measure the stick in travel time from point (A) to point (B). Refer to Illustration 4. Refer to table 2 for the stick in travel time from point (A) to point (B). If the stick in travel time is not within specifications, proceed to Step 5. Perform this step in the reverse order in order to measure the stick out time. Measure the stick out travel time from point (B) to point (A). If the stick out travel time is not within specifications, proceed to Step 5.
- Adjust the stick speed to the correct specification by using the adjustable stick valve (2) which is located on the back of the boom. Refer to Illustration 5.
Illustration 5 | g01013705 |
(2) Adjustable stick valve |