|
|
|
|
|
|
| Illustration 1 | g00721434 |
|
Relief valve locations (A) Main relief valve (B) Boom cylinder line (head end) (C) Boom cylinder line (rod end) (D) Stick cylinder line (head end) (E) Stick cylinder line (rod end) (F) Bucket cylinder line (head end) (G) Bucket cylinder line (rod end) (H) Swing (right) (I) Swing (left) (J) Left travel crossover relief valve for forward travel (upper valve) (K) Left travel crossover relief valve for reverse travel (lower valve) (L) Right travel crossover relief valve for forward travel (upper valve) (M) Right travel crossover relief valve for reverse travel (lower valve) (N) Pilot relief valve (O) Main control valve (P) Pilot filter (Q) Travel motor (right) (R) Travel motor (left) (S) Swing motor |
|
| Relief Valve | Specifications | Torque for Locknut | ||
|---|---|---|---|---|
| New Rebuilt (1) |
Service Limit (2) | |||
| (A) Main relief valve | 35000 + 500 – 1000 kPa (5076 + 73 – 145 psi) | 33000 kPa (4786 psi) to 35500 kPa (5149 psi) |
50 ± 10 N·m (37 ± 7 lb ft) | |
| 36000 + 500 – 1000 kPa (5221 + 73 – 145 psi) (Heavy Lift (if equipped)) |
34000 kPa (4931 psi) to 36500 kPa (5294 psi) |
70 ± 10 N·m (50 ± 7 lb ft) | ||
| (B) Boom cylinder line (head end) | 38000 + 2000 – 1000 kPa (5511 + 290 – 145 psi) | 36000 kPa (5221 psi) to 40000 kPa (5800 psi) |
20 ± 2 N·m (14 ± 1 lb ft) | |
| (C) Boom cylinder line (rod end) | 37000 + 2000 – 1000 kPa (5366 + 290 – 145 psi) | 35000 kPa (5076 psi) to 39000 kPa (5656 psi) |
||
| (D) Stick cylinder line (head end) | ||||
| (E) Stick cylinder line (rod end) | 38000 + 2000 – 1000 kPa (5511 + 290 – 145 psi) | 36000 kPa (5221 psi) to 40000 kPa (5800 psi) |
||
| (F) Bucket cylinder line (head end) | 37000 + 2000 – 1000 kPa (5366 + 290 – 145 psi) | 35000 kPa (5076 psi) to 39000 kPa (5656 psi) |
||
| (G) Bucket cylinder line (rod end) | ||||
| (H) Swing relief pressure (right) | 31400 + 1000 – 1500 kPa (4554 + 145 – 218 psi) | 29400 kPa (4264 psi) to 32400 kPa (4700 psi) |
117 ± 10 N·m (85 ± 7 lb ft) | |
| (I) Swing relief pressure (left) | ||||
| (J) Left travel crossover relief valve (forward) | 37500 + 1500 – 2000 kPa (5439 + 218 – 290 psi) | 34500 kPa (5004 psi) to 39000 kPa (5656 psi) |
92 ± 8 N·m (68 ± 6 lb ft) | |
| (K) Left travel crossover relief valve (reverse) | ||||
| (L) Right travel crossover relief valve (forward) | ||||
| (M) Right travel crossover relief valve (reverse) | ||||
| (N) Pilot relief valve | 4100 ± 200 kPa (595 ± 29 psi) | 49 ± 5 N·m (36 ± 4 lb ft) | ||
| ( 1 ) | A New specification is the performance that can be expected for a new machine. A “Rebuild” specification is the performance that can be expected after rebuilding the components of a system. |
| ( 2 ) | Performance beyond “Service Limit” specifications is an indication of the following problems: improper adjustment, wear, damage of relief valves and damage of pumps. |
| Required Tools | ||
| Part Number | Description | Qty |
| 9U-7400 | Multitach Tool Group | 1 |
| 8T-0470 | Thermometer group | 1 |
| Relief Valves | Pressure change With One Turn Of Adjustment Screw |
|---|---|
| Main valves | 14400 kPa (2100 psi) |
| Line relief valve | 11000 kPa (1600 psi) |
| Swing relief valve | 6800 kPa (985 psi) |
| Travel crossover relief valve | 3050 kPa (440 psi) |
| Pilot relief valve | 620 kPa (90 psi) |
Note: Pressure values in Table 3 are approximate values. Use a pressure gauge for adjustment.
Note: Normal operations of the engine and pumps are necessary for the pressure adjustments. If the results of the pressure adjustment are not correct, then the engine and the pump characteristic curve needs to be checked. Slow output flow from the pump is an indication of air in the hydraulic system. Make sure that no air is present in the hydraulic system. Refer to Testing and Adjusting, “Main Hydraulic Pump Air – Purge”.