SEAL-LIP TYPE 1688508 - Caterpillar

The probable root causes are listed below:
Low air pressure
Wiring
Control valve
Relay valve
Motor
Charge the air system.
Repair the wiring and/or replace the wiring.
Repair the control valve and/or replace the control valve.
Repair the relay valve and/or replace the relay valve.
Repair the motor and/or replace the motor.
The Air Starting Motor has a loss of power.
The probable root causes are listed below:
Low air pressure
Improper lubrication
Worn parts
Air leaks
If necessary, charge the air system. Check the air system for leaks. Check the air compressor for correct operation.
Check the lubrication system.
Inspect parts for wear. Replace any worn parts.
Inspect the vanes for damage. If the width of the vane is less than 32 mm (1.25 inch) at either end replace the vane.
Inspect the rotor bearings. If the bearings are loose or damaged replace the bearings.
Inspect the rotor for scoring. Attempt to remove the scoring with an emery cloth. If the scoring cannot be removed, replace the rotor.
Inspect the cylinders for cracks and/or scoring. If necessary, replace the cylinder.
Check for worn seals. Plug the exhaust and apply 205 kPa (30 psi) to the inlet. Place the unit in a nonflammable liquid for 30 seconds. If bubbles appear, replace the motor seals. The pinion does not engage the flywheel.
The probable root cause is a broken clutch and/or other parts. Replace the clutch.The pinion engages the flywheel but the flywheel does not turn.
The probable root cause is a broken shaft and/or gear teeth. Inspect the shaft and teeth for damage. Replace any damaged parts. The pinion incorrectly engages the flywheel.
The probable root cause is a dry pinion shaft. Remove the pinion and apply grease on the splines and the pinion.