Usage:
Challenger 35 (8DN),
Challenger 45 (1DR),
Challenger 55 (7DM) Agricultural Tractors
- SUPPLEMENT: 02/03/97
Service Magazine; December 16, 1996; Page 2; "New Procedure To Calibrate Tensioner Warning Switch".
Replace Step 15 with the following:
15. If the circuit does not close when the tensioner is at full pressure, remove tensioner switch (1) and remove a 0.25 mm (.010 in) shim (2) (7B-8451).
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The tensioner warning switch must be recalibrated after replacement. Use the following procedure to recalibrate the switch.
NOTE: This procedure replaces the procedure in the service manual.
104-2330 Belt Tensioner Group.
1. Install new switch (1). Reuse shims (2) which were removed from the former switch.
2. Connect an ohmmeter or test light between the switch leads. An open circuit should be indicated.
3. Open tensioner fill valve (3) 1/2to 1 full turn and connect the charging hose. Make sure that the needle valve on the charging hose is closed.
4. Start the engine and run at low idle.
5. Actuate the implement hydraulic circuit in order to pressurize the charging hose.
6. Open the needle valve and allow the tensioner to fill for at least 10 seconds. The ohmmeter (or test light) should indicate a closed circuit. If the circuit does not close while charging the tensioner, proceed to Step 15.
7. Close the needle valve on the charging hose.
8. Place the implement control lever in the FLOAT position.
9. Open the needle valve on the charging hose a small amount in order to start a very slow "bleed off" of hydraulic pressure from the tensioner.
10. Observe and record the pressure reading when the ohmmeter (or test light) indicates that the switch circuit has opened.
11. Repeat Steps 5 through 10 two additional times. Record the pressures observed.
12. Average the three pressure readings. The average reading should be above 10 340 kPa (1500 psi).
13. If the average pressure is below 10 340 kPa (1500 psi), remove tensioner switch (1) and add 0.25 mm (.010 in) shim (2) (7B-8451).
14. Repeat Steps 5 through 12 until the average pressure recorded is above 10 340 kPa (1500 psi).
15. If the circuit does not close when the tensioner is at full pressure, remove tensioner switch (1) and add a 0.25 mm (.010 in) shim (2) (7B-8451).
NOTE: Add or remove only one shim at a time. If it is not possible to achieve the conditions specified using 0.25 mm (.010 in) shims, a 0.013 mm (.005 in) shim (119-9738), can be used to provide finer adjustment.
16. If the switch cannot be satisfactorily calibrated, replace belleville washers (4) (7S-9847) and repeat the calibration procedure.