You most likely have a leak in either the master cylinder or the slave
cylinder and therefore the pedal can't deliver any pressure because the
hydraulics are no longer sealed.  Sometimes they take a few days to leak
down and other times it can be quick.  Had it happen both ways.

If it is the master cylinder, there will be a puddle of fluid right
underneath the brake pedal.  The slave is on the left side of the
transmission.  You may see a puddle under it, or fluid on it, or the
fluid may be trapped inside the little bellows on the slave cylinder.

Having a clutch job done does not mean the hydraulics were checked and
replaced.  That is usually a whole separate job.

Topping off the brake / clutch fluid reservoir will not solve the
problem as there is now air in the lines.  You will have to bleed the
lines to get the air out before you would see any improvement.  This
improvement would be temporary if there is a leak at the slave or master
cylinder. My bet is on the slave cylinder.

When you find which one is leaking, it needs to be replaced.  Folks
disagree over whether to replace both the master and slave or just the
offending unit.  Some believe that when one fails the other has got to
be close behind, but I don't think there is any hard data to support
that assertion.  Just anecdotal data.  But if it has been a long time
since either was replaced, it can't hurt to do both.

I have never had a master cylinder fail, but have heard of others who
have never had a slave cylinder fail.

I have replaced the slave on one van or another a cumulative total of
about 6 times, and have done the job 4 times myself.  It isn't that bad
of a job although removal and installation of the cylinder is difficult
due to the strange design of the bracket on which is is mounted.

If you want to try it yourself, let me know and I'll send you some
materials on how to do it.

Sam

--
Sam Walters
Baltimore, MD

89 Syncro GL, Zetec Inside
85 Westy Weekender
85 Mercedes Benz 300D Turbodiesel - to become veggie oil powered

All incoming and outgoing email scanned by
automatically updated copy of Norton AntiVirus.