Why changing clutch master cylinder fluid makes my clutch grinding sound go away

[archyx]

I thought I had a bad throw-out bearing on my winter beater '90 Nissan Pathfinder 4WD 'cause every time I press the clutch pedal, it would have a LOUD sqealing/grinding sound, but no sound at all if you don't press the clutch pedal. It's 141k miles on factory clutch so I think it's due time for the t-bearing.

However, yesterday while I was doing some work in the car (changine brake master cylinder), I noticed that the liquid in the clutch master cylinder is like mud water. So I just use a syringe to sip all the dirt fluid out and pour Dot3 brake fluid back in. I did this about 2 times to make it look reasonably clean.

Then today when I drive the car, it never has that squealing sound any more. The first time ever it's so quiet for the past 2 months I owned it.

Why simply changing the clutch master cylinder fluid would make the sqealing/grinding sound go away?

[UKFan4Sure!]

That is amazing! I too have found that changing my engine oil sooner made my cars last longer. For example, I used to have a car I changed the oil every 75000 miles, I only lasted 76000 miles before the engine blew. Now I change the oil on my new one every 5000 per the owner's manual and darned if it hasn't lasted for 105000 now and seems to be OK! I think we may be on to something ...... :eek: :eyecrazy :rolleyes