Hello, I have recently noticed on my 87' JDM BJ70 that while idling my clutch pedal feels hard to press. Once the vehicle is moving the clutch pedal moves much more easily. I had read other threads regarding clutch vacuum problems but I'm not sure how to properly diagnose. Is there a quick troubleshooting procedure that can be used to isolate this problem? I'm scared I'm going to press the clutch pedal through the floorboards one day! Thanks in advance.