Brake Bleeding

["Rich Wagner" <drsavage@xxxxxxx>]

Hi gang,

Recently, a member wrote in asking about bleeding his brakes, which were
resisting the proceedure.  I recently rebuilt the rear calipers on my GTV6,
and learned something new.  Let me explain.

After installing the rebuilt calipers and reconnecting the lines, I filled
the fluid reservior, cracked open the bleed screws, and let gravity do its
thing.  After a few minutes, the calipers were full, and I began to see
fluid flowing through my clear bleed tubing.  I closed the bleed screws and
checked the pedal.  Not good.  Very soft.  I had previously bled these
brakes and learned a few tricks.  The most important for the GTV6 is: 
bleed both sides of a caliper simultaneously.  This is the technique
recommended by Alfa in the shop manual.  Previously, I bled the calipers
one piston at a time with acceptable results.  After I discovered this
technique in the manual, I tried it and it worked even better, resulting in
a VERY firm pedal.  Anyway, I put my wife in the driver's seat and began
the dance:  open the bleed screws; "pedal to the floor, honey"; close bleed
screws; "okay, up".  After doing both calipers, things improved a bit. 
Still not right, though.  No problem, repeat the process.  After a few
repititions, things were still improving.  I checked the reservoir, which
was now low, and refilled it with the fluid expelled during the bleed. 
This is typically not recommended, since you may be adding dirty fluid.  My
system had just been flushed, however, and so I was willing to risk it. 
Well, there's a second reason not to recycle the fluid.  After it comes out
of the system, its full of tiny, suspended air bubbles.  Well, the next
cycle of bleeding resulted in a pedal which was actually SOFTER! Try after
try, I couldn't get the pedal any firmer, and it wasn't too firm to begin
with.

I called Mark, my local Alfa guy, and he passed this tip on to me.  It was
passed on to him by an old Lucas mechanic, who had lots of experience with
Rolls Royces.  I'll pass it on to you.  He told me to use a board or
something else to depress the pedal as far is it will go, and leave it
overnight.  I have a lot of experience bleeding different kinds of brakes,
and this sounded like snake oil to me.  Mark could tell, and basically
said, "Humor me.  Try it."  I held the brake down with a board between the
pedal and the driver's seat, and left it overnight.  The next morning, I
pulled the board out and stepped on the pedal, knowing it would still go to
the floor.  It didn't.  It was perfect.  I should have known that the
correct technique would involve keeping your cool, walking away, and having
a glass of wine.  I suppose the old Lucas guy must have had a cup of tea. 
Cheers.


Rich
Manitou Springs, CO
'82 GTV6 Balocco

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End of alfa-digest V7 #252
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