Persistant clutch hydraulic leak

Son's 97 accord had an obviously leaking slave cylinder, so he
recently changed it. The master was changed a year earlier. Bled it
down and all is well, good clutch disengagement everything working
properly.

However, about every three weeks the resevoir drains down and has to
be replenished. Have carefully checked both the master and slave, no
fluid leaking. Checked the resevoir to master piping, no leaks.
Checked all the piping to the damper, no leaks. Checked the damper to
the slave, no leaks.

Has to be leaking somewhere. But where?

Frank

 

Look under the dash at the pedal pushrod where it goes into the firewall.
Any fluid there?

 

inside the car. when re-fitting a new master cylinder, pay attention to
the little drain hole at the bottom where it bolts on - make sure it's
not clogged with grease. it won't stop the cylinder leaking, but it'll
make sure it's visible and outside.

 

I second that. Same thing happened on my old Prelude - dealership ordered a
new master cylinder. After they went in, it was a bad washer. They
replaced the washer and I never had to pay for the master cylinder - leak
was fixed.

-Dave

 

First place I looked. Usually when they fail you get fluid passing by
the piston packing and oozing down the inside of the firewall.
Nothing there.

I'll have to check at different temperatures, maybe something is
opening up in either hot or cold conditions, or after heavy clutch
use. I've only checked it cold with someone both pumping and holding
the clutch pedal.

Frank

 

Well, brake fluid doesn't just disappear into nothingness the way brake
cleaner or acetone do. It's leaking SOMEWHERE.

You need to do some very close investigation here.

Have you re-checked the slave, including peeling back the dust boot to see
what's inside?

 

Yep, I know.

Second place I looked. Nothing in the dust boot and when the clutch
pedal is pressed nothing coming past the piston rod, tubing connector,
or bleeder valve.

I'll go after it when I get the car back. Probably Thanksgiving.
Until then, son will have to check and fill periodically.

Frank
Frank

 

Good luck.