Tennant ATLV 4300 Service Manual page 159

Model 70160
Fault - Logic Troubleshooting
Diagram Action Step Comments
1 Inspect External Control Linkage for:
a. misadjustment or disconnection
b. binding, bending or breakage
c. misadjusted, damaged or broken neutral return spring
2 Inspect Servo Control Valve for: (if used)
a. proper inlet pressure
b. misadjusted, damaged or broken neutral return spring
c. galled or stuck control spool
d. galled or stuck servo piston
3 Inspect System Relief Valves* for:
a. improper pressure relief setting
b. damaged or broken spring
c. valve held off seat
d. damaged valve seat
4 Check Oil Level in Reservoir:
a. consult owner/operators manual for the proper type
fluid and level
5 Inspect Heat Exchanger for:
a. obstructed air flow (air cooled)
b. obstructed water flow (water cooled)
c. improper plumbing (inlet to outlet)
d. obstructed fluid flow
6 Inspect Heat Exchanger Bypass Valve for: (if used)
a. improper pressure adjustment
b. stuck or broken valve
7 Inspect Pump Bypass Valve for: (if used)
a. held in a partial or full open position
8 Inspect Inlet Screen or Filter for:
a. plugged or clogged screen or filter element
b. obstructed inlet or outlet
c. open inlet to charge pump
9 Check System Pressure:
a. See figure 60 for location of pressure gauge installation.
b. consult owner/operators manual for maximum system
relief valve settings
10 Check Charge Pressure:
a. See figure 60 for location of pressure gauge installation.
b. consult owner/operators manual for maximum charge
relief valve settings
11 Inspect Charge Relief Valve for:
a. improper charge relief pressure setting *
b. damaged or broken spring
c. poppet valve held off seat
12 Inspect Motor for:
a. disconnected coupling
13 Inspect Charge Pump for:
a. broken or missing drive key
b. damaged or missing o-ring
c. excessive gerotor clearance
d. galled or broken gerotor set
* System/Charge Relief Valve Pressure Settings for Eaton's
Variable Displacement Controlled Piston Pumps
Inlet Vacuum
Case Pressure
Charge Pressure
System Pressure
The high pressure relief valves are all factory preset and
cannot be readjusted.
The pressure setting and assembly number is stamped on
each high pressure relief valve cartridge.
Valve Identification Example:
110603-500
Relief Valve Assembly Number
17
6 inHg max.
25 PSI maximum
100 to 150 PSI Standard
200 to 250 PSI Optional
250 to 300 PSI Optional
5000 PSI maximum
3000 PSI continuous
5000
Relief Valve Setting