Novice Mechanics Screw Up
or
British Engineers Aren't as Stupid
as They Might Seem
I write:
>Did we do something wrong???
YES!
The final outcome of the caliper rebuild story. As you may recall,
Chuck and I bebuilt our front brake calipers last weekend and could not
get all of the air out of the system.
On Saturday we tried more bleeding. We followed everyone's advice to
try bleeding the rear brakes. No air came out. So back to the
fronts. We thought there must still be air stuck inside the calipers.
Isn't it stupid, we cursed, that the calipers are designed to have the
bleed screws on the bottom! How is the air going to get out if it all
rises to the top? We finally decide to take the calipers OFF the car
and bleed them while holding them upside down. We do the first one.
Wow! Look at all that air in there! Geez. What a stupid design! We
struggle to get this caliper back on the car. This is difficult
because the rotor is new, the brake pads are thick, and the pistons are
pushed out. After struggling for half an hour with this caliper and
finally succeeding in getting it on, I say to Chuck, "Are you SURE the
bleed screws are supposed to be on the bottom?" We somehow both
remember the bleed screws were on the bottom before we took eveything
apart. We even labeled the individual pistons when we took them apart
so we knew how to put them back together and we _thought_ we knew which
side of the car each caliper went on. But there's the picture in the
manual -- bleed screws on top -- we've reversed the calipers! Boy do we
feel stupid. Although it is not impossible that someone else, years ago,
did the same thing and actually got it to work. So after much practice
taking the calipers on and off, we were able to put eveything back
together quickly. The bleed actually works and Sunday we take the car
for a drive down to Pescadero.
I guess after this incident and the fact that we used up our first tub
of hand cleaner this weekend, we have been initiated.
So, advice to any novices out there: be sure to keep track of where
things go! Your life may depend on it!
(Another thing -- we also must have reversed the bleed screws on the
calipers and they both leaked until we switched them back.)
Lydia gregoret@cgl.ucsf.edu
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