Clutch causing vacuum leak (1 Viewer)

[87 HJ60]

I had a thread regarding hearing a mystery noise inside my Land Cruiser. I found out that the noise was being made whenever I step down on the clutch pedal. Seems like I have a vacuum leak somewhere. If i step on the clutch a few times quickly the pedal is hard to depress (vacuum depleted) .
Can someone explain to me how the clutch pedal system with the vacuum assist works.
Also just to refresh those that may not have seen my other thread. The noise is a high pitch squeal that sounds like "weeeeeeeee" when the clutch pedal is depressed; not all the time but sometimes.
I presume it's the clutch system that has the leak and not the brake system that's leaking the vacuum. btw I have a diesel so that means the vacuum reservoir supplies both the brake and clutch with vacuum.
Any input..?

 

[debushau]

A high pitch squeal when the clutch is depressed sounds like a bad throwout bearing on the clutch.

Sort of surprising that the clutch is vacuum assisted - a clutch is not exactly difficult to push with the standard master cylinder on an FJ60.

 

[87 HJ60]

It's not the throwout bearing. It's definitely a vacuum leak of some sort somewhere.