SPRING 1873369 - Caterpillar

Illustration 5 g00336840
Use the following procedure in order to charge a belt tensioner that does not have trapped air. You may need the following procedure when you remove belts or when you install belts. Also, you may need this procedure when you change the track gauge. Note: When you use a new hose group, remove the air that is trapped in the hose. See "Fully Tensioning an Open System".
Verify that filler valve (1) and purge valve (2) are closed.
In order to connect the hose group, perform Step 1 and Step 2 in "Detension the Track".Note: If you cannot connect the hose group to the nipple, there may be a buildup of hydraulic pressure between the filler valve and the nipple. In order to release the pressure, see "Release the Pressure Between the Nipple and The Filler Valve".
Start the engine. Run the engine at LOW IDLE. Hold the implement control lever in the RAISE position.
Slowly open filler valve (1) by 1/2 turn to 1 turn. This allows the belt tensioner to fill. Continue charging the system until a system pressure of at least 17255 kPa (2500 psi) is indicated by the pressure gauge.
While you maintain the implement control lever in the RAISE position, close the hand valve on the hose group in order to isolate the pressure gauge and the belt tensioner.Note: Perform Step 6 through Step 8 in order to test for the correct nitrogen pressure in the accumulator. Step 6 through Step 8 must be completed whenever you detension the belt tensioner or you service the belt tensioner.
Place the implement control lever in the FLOAT position. Stop the engine.
Open the hand valve on the hose group by a small amount in order to relieve the hydraulic pressure from the belt tensioner.
Watch the pressure gauge closely. Observe when a sudden decrease in hydraulic pressure occurs. The last pressure value that was observed before the sudden decrease indicates the nitrogen pressure in the accumulator. The nitrogen pressure should be between 10000 kPa (1450 psi) and 14100 kPa (2050 psi).Note: If the amount of the decrease in pressure is greater than 1380 kPa (200 psi), the measurement of nitrogen pressure will be incorrect. Repeat Step 10 through Step 12 at a slower rate until the decrease is less than 1380 kPa (200 psi).
A low nitrogen pressure may indicate that an accumulator is damaged. The problem should be corrected before you operate the machine. Use the 9U-6740 Gas Charging Kit in order to recharge the accumulator.
Start the engine. Run the engine at LOW IDLE. Hold the implement control lever in the RAISE position.
The track tensioning mechanism contains a hydraulic accumulator which acts as a spring to maintain track tension.Check the accumulator pressure whenever the track is adjusted or repaired.
A rupture disc is used as a pressure release in the charging manifold for the track tensioner.Hydraulic oil pressure can increase because of low nitrogen pressure in the accumulator.In the event of tensioner overpressure, this disc will vent oil and relieve all track tension.Replace