Milano braking

["Bain, Bill" <Bill.Bain@domain.elided>]

Damian sez: 

>I am having an interesting brake issue. This is in regards to my 87
Milano. Under braking it will dive to the left very quickly (this really
sucks at 80mph) and then straighten back out. Now...my first thought is
warped rotor but there is no pulsing through the steering wheel. This
happened for a few days and now under braking it dives to the right.
Curiouser and curiouser. 

I'm starting to think my brake lines are geeked and needs to be replaced
(at the least) or a caliper rebuild is in order (ugh). Probably all of
the above, one doesn't want to mess around with brakes. 

I guess the odd thing is that it started diving to the left and now the
problem is that it is diving to the right. Darned little gremlins, can't
make up their minds. I guess I have my project for this weekend...

A couple thoughts here: 

If the car is pulling on initial application and then braking "straight"
the things I 'd check are (in order): 

1. Check the pad wear.  If you have unequal wear, there may be a stuck
caliper (or, more likely one side is stuck) or some such.  What happens
is that the caliper on the "good" side has more initial clamping force
and the car will pull in the direction of the side with more braking
force.  As the car slows the effect is less pronounced, so it feels like
it's braking "straight."  It strikes me as possible that in an extreme
situation where one pad in a caliper is not even or barely touching the
rotor, you could also build up enough heat in the other side to boil the
fluid under hard braking and exacerbate the problem further but that's a
surmisal on my part.

Generally brake lines with internal restrictions prevent the caliper
from releasing since the restriction acts as a sort of "one way' valve,
but if the line is restricted enough the caliper may not get enough
fluid to clamp properly.  Again, looking at the brake pads will tell
since if it ain't clamping, it ain't using up the pads.

2.  Since it was initially left and is now right, I'd be wary of
something "loose" in the front suspension.  Any slop will allow the
car's front end to become not quite parallel to the rear end and have
the effect of having the steering wheel turned slightly.  Often old
Spiders will "crab" on acceleration due to the rear trailing arm to body
bushings wearing out and the rear axle moving slightly under engine
torque.  It's the same idea.  I'd check the rear suspension too, but I'm
not quite as familiar with the deDion set up as some are so I can't tell
you where to look.

3. How's the alignment? 

Bill Bain 
AROC Atlanta 
'83 Spider (Only Alfa at the SCCA Autocross yesterday -- where was every
one else?) 
'87 Milano (rear caliper brake fluid leak has disappeared afterI bled
the brakes -- maybe the bleed screw wasn't quite tight?)
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