Richard, while you hae found some other interesting troubles, I still
maintain that your problem has to do with your master cylinder. The fact
that it takes two pumps to get any pressure is VERY typical. You have an
internal leak in the m/c, the first pump seals it up enough for the second
pump to apply brakes. I have seen this countless times.
Patrick Bowen
-----Original Message-----
From: Richard B Gosling [mailto:Gosling_Richard_B@perkins.com]
Sent: Monday, October 16, 2000 9:45 AM
To: npenney
Cc: spitfires
Subject: Re: What's wrong with my brakes?
The continuing saga of Daffy's brake woes...
Today I checked the passenger side front caliper, after I discovered on
Friday
that the drivers side had pads that were binding in the calipers - the
metal
backing on the pads was a tiny bit to tall to fit in the gap in the
calipers.
The passenger side was even worse, one of the pads was jammed solid in the
caliper. This had the effect that it had hardly moved since installation 6
months ago, and the other pad had worn down substantially instead. I
actually
had to take the caliper off the hub to be able to get the pad free.
Woohoo, I thought, here we have a thoroughly good and understandable and
FIXABLE cause for all my brake problems. I could also see daylight between
the pads and the disc, which Nolan suggested was a good sign that there was
too much movement before the pads started their work. I ground a little
metal
of the top and bottom of the pad backing, and re-fitted - everything now
nice
and freely moving. Dropped the bonnet back down, went for a quick spin
round
the car park, B******S, brakes just as bad as before. On damp tarmac, they
would not even lock up with my foot on the floor - at least on the first
pedal
press, the second press was fine, as always.
So, I tried re-bleeding by brakes. Both rear wheels, nothing but clear,
bubble-free fluif. Front passenger wheel, several bubbles - could that be
the
cause of all my problems? Front drivers side - undo the bleed screw,
nothing
comes out, no fluif, no air, nothing. Remove the bleed screw completely -
nothing but a tiny dribble of fluif down the caliper. Blow through the
bleed
screw - flows freely, so no problem with the screw itself (but brake fluif
really doesn't taste good, does it??!) WHAT'S GOING ON HERE?? I should
mention I'm using an Eezibleed - air pressure from the tyre is used to
increase pressure in the fluif reservoir, so the fluif is literally blown
down
the pipes. Should I try the original method of bleeding, pumping the
pedal,
to see if I can blow the blockage clear?
Anyway, despite freeing up all my sticky brake pads, and re-bleeding the
system
to get some more air out, my brakes are still as crap as ever. Tomorrow I
will try unblocking the blockage in my front drivers side caliper by
pumping
on the pedal with the bleed screw removed (unless anyone advises me not
to..),
and I may try adjusting my rear brakes - i guess the handbrake does not
operate as low as it used to, so there is a little slack there that could
be
taken up. After that, I am stumped again - unless it really is the M/C,
but
the unerring repeatability of the first-press-little-braking,
second-press-fine thing does make this a less likely option.
The moral of my investigations today is, if you have to use a hammer to
install
your brake pads (yes, I confess, I did - not very clever!), you are not
doing
it right!! Has anyone else had to grind metal off their pad backings (i.e.
the pads have been a little too big), or have my calipers somehow,
mysteriously, got a hole that is too small?
Many thanks to all of you, particularly Nolan, who have advised me over the
last week or so. It is not over yet...
Richard and Daffy (all go, no slow)
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