Procedure for Traction Circuit Relief Pressure Test
1.Make sure hydraulic oil is at normal operating tem- perature by operating the machine for approximately 10 minutes. Make sure the hydraulic tank is full.
CAUTION
Move machine to an open area, away from people and obstructions.
2.Drive machine to an open area, lower cutting deck, turn the engine off and engage the parking brake.
CAUTION
Prevent personal injury and/or damage to equip- ment. Read all WARNINGS, CAUTIONS and Pre- cautions for Hydraulic Testing at the beginning of this section.
3.Connect a 10,000 PSI (700 bar) gauge to traction cir- cuit test port for function to be checked (Forward or Re- verse: Fig. 22 or 23).
4.After installing pressure gauge, start engine and run at idle speed. Check for hydraulic leakage and correct before proceeding with test.
5.Operate the engine at full speed (2870 RPM). Make sure that transport/4WD switch is in the transport posi- tion.
6.Sit on seat, apply brakes fully and slowly depress the traction pedal in the appropriate direction. While pu- shing traction pedal, look at pressure reading on gauge:
GAUGE READING TO BE:
Forward: 3750 to 4250 PSI (259 to 293 bar)
Reverse: 4750 to 5250 PSI (328 to 362 bar)
7.Release traction pedal and stop engine. Record test results.
8.If traction pressure is too low, inspect traction pump relief valves (Fig. 24). Clean or replace valves as neces- sary. These cartridge type valves are factory set and are not adjustable. If relief valves are in good condition, trac- tion pump or wheel motors should be suspected of wear and inefficiency.
NOTE: Seal leakage across pilot directional valves PD1 and PD2 in 4WD manifold can also cause low for- ward traction pressure with reverse pressure meeting specifications.
9.When testing is completed, disconnect pressure gauge from test port.
2
1
Figure 22
1. Forward traction port 2. LH front tire
| 2 |
1 | Hydraulic System |
| |
Figure 23 | |
1. Reverse traction port | 2. RH front tire |
RIGHT | 2 | |
FRONT | ||
| ||
| 3 | |
| 1 |
Figure 24
1. | Forward relief valve | 3. Traction pump |
2. | Reverse relief valve |
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Groundsmaster | Page 4 | Hydraulic System |
