Clutch fluid level

[cobrahunter]

Pretty basic question:

How often should I check/change my clutch fluid? Last time I know it was changed was when I had my clutch replaced about 3 1/2 years ago. Not sure if this is related, but going into reverse can be a real bi*ch. And when I'm WOT going from 3 to 4, the shifter doesn't go in completely, and I sometimes hear the gears grind for a split second. '98 Z28 has about 90K miles with original transmission.

[ggino85]

i would like to hear some ideas on this as well. a mechanic at a (questionable) shop was telling me that i dont want to drain the clutch fluid because it will stire up particles and cause the clutch/slave cylinder? to fail.