having some clutch issues need help

[mikey435]

okay guys so my 1990 zr1 #1330 was driving fine all day. on my way home from work the clutch pedal lost all pressure and went straight down to the floor! the car only has 80k on her. this happened to me once before and i changed slave cylinder and master cylinder and it worked. the ironic thing is that after i got the car home i got inside pumped the clutch about 25 times and had pressure and was able to drive it into my garage. ANY HELP FROM THE BROTHERHOOD WOULD BE GREATLY APPRECIATED I REALLY LOVE THIS CAR AND JUST WANT TO GET HER RUNNING RIGHT!

[scottfab]

I'd start by flushing the fluid.
If you had a bit of moisture build up and it
vaporized you'd have an air pocket that could condense back to
a water droplet.
How is the fluid level?
Another possibility is that a slow leak has lowered the level
to the point where it's sucking air.

[-=Jeff=-]

More questions to add to Scott's


When were the Master and Slave replaced? Are they Cast replacements or OEM?
Was the Clutch line replaced as well?
did you lose the pedal the one time only?

Let's start there before going any further in the Diagnosis

[mikey435]

I haven't checked fluid level yet but I will. The slave and master were replaced in may and they are cast. The reason I replaced both was I lost pedal once before and had heard of these being common problems on the zr1. But this was in may also clutch line was not replaced.

[-=Jeff=-]

okay this is a test Bill B had me try

if the car is parked uphill for a few hours (could be nose up on Stands/ramps in the garage)

After sitting for that time.. go out to car, depress Clutch, Start Car, then shift to reverse, it is not easy or will not go in then the Master is an issue

I had cast pieces as well, but felt the clutch was not 'right'

I bought new OEM type parts from Jim Jandik.. Much better operation of the clutch

[Hib Halverson]

Are there any leaks in the system?

[mikey435]

turns out fluid level was low and it was sucking air. flushed and bled the system and im now happily rowing the gears in the beast again thanks for all the help guys.

[scottfab]

Originally Posted by mikey435

turns out fluid level was low and it was sucking air. flushed and bled the system and im now happily rowing the gears in the beast again thanks for all the help guys.

I'd keep a close eye on it. Obviously there is a leak. Hopefully very slowwwwwwww.
I believe I'll be "rowing" a few gears here in an hour.
Nice cool fall morning for it.

[rkampf]

Any chance you can give a quick description on how to flush/bleed the system. Ive just had my clutch fail (very low mileage) and my reservoir is low. I'd like to bleed the system before trying anything more extensive.

[scottfab]

Originally Posted by rkampf

Any chance you can give a quick description on how to flush/bleed the system. Ive just had my clutch fail (very low mileage) and my reservoir is low. I'd like to bleed the system before trying anything more extensive.

Depending on how much of a hurry you are in you can do it similar to
bake bleeding (some one press while someone else crass open the bleeder
valve on the slave cyl.)
Or you can fill the master res and then crack the bleeder on the slave cyl and let it drip keeping the master cyl full.
Once the fluid goes clear you done. Close the bleeder.

The challenge you'll have is cracking loose the bleeder.
If it refuses to budge you'll likely have to clamp on a visegrip to loosen it.