Clutch pedal 'fades' ?

[Shagger]

All,

I need a bit of help here. I have a 1996 Mazda 626 with a manual transmission. The clutch pedal gradually 'fades' with every shift. I have to lift it with my foot so I can make those last few shifts into 5th gear. My suspicion is the Clutch master cyclinder is failing / failed? Any ideas on how I can test this theory?

Thanks!

 

[Steve S]

Change or rebuild the clutch M/C.

 

[javacontour]

Look for fluid leaks?

Pump it up?

 

[Shagger]

I don't see any fluid leaks...

What do you mean by pumping it up?

 

[aquariuscsm]

Yep,you`re losing hydraulic pressure. Probably time for a new slave,or master cylinder.

 

[USA1]

If you pump the pedal then hold it down, and your clutch fully disengages, it will indicate air in your system which may have entered through a leak in either cylinder or the line, connections etc. This is a hydraulically operated clutch, right?!

 

[labman]

I guess I always knew which was was bad because it was leaking externally. I guess you could disconnect the line from the MC and plug it. Then hold steady pressure on thepedal. If it slowly goes down, the MC is bad. If not, try the slave.

 

[Shagger]

Originally Posted By: USA1
If you pump the pedal then hold it down, and your clutch fully disengages, it will indicate air in your system which may have entered through a leak in either cylinder or the line, connections etc. This is a hydraulically operated clutch, right?!

This is a hydraulically operated clutch. The clutch does disengage, and I can start the car, shift a few gears, then lift the pedal with my foot and shift a few more times. So maybe I should bleed the hydraulic line for the clutch? Then if that doesn't solve it, install a new Clutch mc?

 

[javacontour]

Originally Posted By: Shagger
I don't see any fluid leaks...

What do you mean by pumping it up?


Does it work better if you pump the pedal a few times. I had a master cylinder that was failing in this fashion. If you pressed once, it wouldn't fully engage. If you pumped it a few times, I would work fine, for a while. Eventually it would need a few pumps to fully engage.

After I inspected the clutch master cylinder, I saw it leaking. (BTW, the leak was inside the car, not in the engine compartment.)

 

[stockrex]

flush it, use mityvac or something similar to change the fluid in it.
mine would boil when it was really hot back in kansas city ;-)

 

[Scott_Tucker]

It is likely your master cylinder is bypassing.

 

[Shagger]

Originally Posted By: javacontour
Originally Posted By: Shagger
I don't see any fluid leaks...

What do you mean by pumping it up?


Does it work better if you pump the pedal a few times. I had a master cylinder that was failing in this fashion. If you pressed once, it wouldn't fully engage. If you pumped it a few times, I would work fine, for a while. Eventually it would need a few pumps to fully engage.

After I inspected the clutch master cylinder, I saw it leaking. (BTW, the leak was inside the car, not in the engine compartment.)

Bingo! - The Clutch mc is leaking inside the car - ok! At least now I know that it is definetly the MC! Thanks to all! Now - who is not busy this weekend to come by and help me replace it?!?

 

[mechtech2]

Master cyl, slave cyl, or both.