Bleeding dual booster brakes on Spider

[David Rubie <drubie@domain.elided>]

Hello all,

Finally got my new '75 spider home a week ago,
bit of a drama driving it around Sydney as it
had no useful brakes.  Didn't notice on the (very
brief) test drive that they were so bad...
(Details - 1975 Spider Veloce, Australian
delivered (Euro spec I suppose), RHD).
This is one of the models with 2 vacuum
boosters and a master cylinder under the
floor.  Symptoms:  The pedal was hard and
very low.  Pumping the pedal didn't bring it
back up.  The car did brake eventually but
pulled to the left.  Scary.

Anyway, The vacuum hoses to the boosters were
cracked/leaking so I replaced them.  This
encouraged brake fluid to come out into the vacuum
hoses from the stuffed boosters.

I pulled the (Benditalia) boosters and had
them sleeved/kitted and re-installed them.
Bought 2 bottles of brake fluid and bled out
the disgustingly dirty fluid from
the system.  Boosters hissed properly
when the engine was started, so they look
like they're holding vacuum.

I then bled the brakes, starting at the right rear,
left rear, right front, left front.  Pulled out
copious amounts of dirt, 2 different colours of
fluid and a lot of air from the installation
of the new boosters.  Didn't stop bleeding each
corner until a nice even flow of new fluid
minus bubbles came out.

Made sure nothing was leaking, then test drove it.

Now, much better brakes (stops in a straight line)
but pedal travel is still long and can be pushed
directly to the floor if enough force is supplied.

I then noticed the brake bleeder on the master
cylinder today.  I bled that (a nice big burp of
air, dirt and old fluid came out).  The brakes
now engage much earlier but the pedal still feels
awfully soft.

I think the master cylinder might be stuffed but
then again I don't know whether there is a special
trick to bleeding the brakes.  Anybody know?

Sorry about the long post!

dave.
brakeless in Sydney.

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