* Low clutch fluid. The clutch fluid is responsible for transmitting the force from the clutch pedal to the clutch master cylinder. If the fluid is low, there won't be enough force to engage the clutch.
* Air in the clutch line. Air in the clutch line can also cause the clutch to slip. This can happen if the clutch fluid was not bled properly or if there is a leak in the clutch line.
* Faulty clutch master cylinder or slave cylinder. The clutch master cylinder and slave cylinder are responsible for actuating the clutch. If either of these components are faulty, the clutch will not engage properly.
* Worn clutch disc. The clutch disc is responsible for transferring the power from the engine to the transmission. If the clutch disc is worn, it will not be able to grip the flywheel properly and the clutch will slip.
* Faulty pressure plate. The pressure plate is responsible for holding the clutch disc against the flywheel. If the pressure plate is faulty, it will not be able to hold the clutch disc in place and the clutch will slip.
If you are experiencing a lack of pressure when engaging the clutch in your 86 b2000, it is important to have the vehicle inspected by a qualified mechanic to diagnose the problem and make the necessary repairs.