Note: 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. Performance beyond Service Limit specifications is an indication of these problems: improper adjustment, wear, damage of relief valves and damage of pumps.
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| Illustration 1 | g02172657 |
Relief valve locations (1) Cab (2) Right swing motor (3) Left swing motor (4) Main control valve (5) Pilot manifold (6) Travel motor (right) (7) Travel motor (left) (A) Stick cylinder line (rod end) (B) Boom cylinder line (rod end) (C) Bucket cylinder line (rod end) (D) Signal relief valve (low pressure) (E) Signal relief valve (high pressure) (F) Stick cylinder line (head end) (G) Boom cylinder line (head end) (H) Bucket cylinder line (head end) (J) Right swing motor (right relief valve) (K) Right swing motor (left relief valve) (L) Left swing motor (right relief valve) (M) Left swing motor (left relief valve) (N) Margin pressure adjustment screw (rear pump) (P) Margin pressure adjustment screw (front pump) (R) Pilot relief valve (S) Right travel crossover relief valve for forward travel (upper valve) (T) Right travel crossover relief valve for reverse travel (lower valve) (U) Left travel crossover relief valve for reverse travel (lower valve) (V) Left travel crossover relief valve for forward travel (upper valve) (W) Differential relief valve (X) Differential relief valve (Y) Control valve for counterweight cylinder | |
| Relief Valve | Specifications | Torque For Locknut | ||
|---|---|---|---|---|
| New | Rebuild | Service Limit | ||
| Signal relief valve (low pressure) | 35000 + 500 - 1000 kPa (5076 + 73 - 145 psi) |
35000 + 500 - 2000 kPa (5076 + 73 - 290 psi) |
60 ± 10 N·m (45 ± 8 lb ft) |
|
| Signal relief valve (high pressure) | ||||
| Margin pressure adjustment screw (rear pump) | 1960 ± 50 kPa (285 ± 7 psi) |
1960 ± 50 kPa (285 ± 7 psi) |
28 ± 7 N·m (21 ± 5 lb ft) |
|
| Margin pressure adjustment screw (front pump) | ||||
| Boom cylinder line (head end) | 37000 + 500 - 1000 kPa (5366 + 73 - 145 psi) |
37000 + 500 - 2000 kPa (5366 + 73 - 290 psi) |
33 ± 10 N·m (24 ± 7 lb ft) |
|
| Boom cylinder line (rod end) | ||||
| Stick cylinder line (head end) | ||||
| Stick cylinder line (rod end) | ||||
| Bucket cylinder line (head end) | ||||
| Bucket cylinder line (rod end) | ||||
| Right swing motor (right relief valve) | 30350 + 500 - 1000 kPa (4402 + 73 - 145 psi) |
30350 + 500 - 2000 kPa (4402 + 73 - 290 psi) |
155 ± 29 N·m (115 ± 22 lb ft) |
|
| Right swing motor (left relief valve) | ||||
| Left swing motor (right relief valve) | ||||
| Left swing motor (left relief valve) | ||||
| Left travel crossover relief valve (forward) | 39250 + 1500 - 2000 kPa (5693 + 218 - 290 psi) |
39250 + 1500 - 3000 kPa (5693 + 218 - 435 psi) |
155 ± 29 N·m (115 ± 22 lb ft) |
|
| Left travel crossover relief valve (reverse) | ||||
| Right travel crossover relief valve (forward) | ||||
| Right travel crossover relief valve (reverse) | ||||
| Pilot relief valve | 4120 ± 100 kPa (598 ± 15 psi) |
16 ± 1 N·m (12 ± 1 lb ft) |
||
| Differential relief valve (rear pump) | 3300 ± 50 kPa (439 ± 7 psi) |
Differential relief valves should not be serviced. | ||
| Differential relief valve (front pump) | ||||
| Counterweight cylinder | 20600 + 1000 - 0 kPa (2990 + 145 - 0 psi) |
30 ± 2 N·m (22 ± 1 lb ft) |
||
| Relief Valves | Pressure change With One Turn Of Adjustment Screw | |
|---|---|---|
| Signal relief valves | Implement | 10600 kPa (1535 psi) |
| Travel | 7050 kPa (1025 psi) |
|
| Line relief valve | 6850 kPa (1000 psi) |
|
| Swing relief valve | 10000 kPa (1450 psi) |
|
| Travel crossover relief valve | 10000 kPa (1450 psi) |
|
| Pilot relief valve | 690 kPa (100 psi) |
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Note: Pressure values in Table 2 are approximate values. Use a pressure indicator for adjustment.