>>1441624what causes brake squeel is un even or inconsistant contact
clean the wheel rim
most pads are mounted slightly too low and form a lip of un worn brake pad
remove brake pads and level their surface with sand paper or smooth concrete
re attach the brake pads so that they make the maximum possable contact with the wheel rim
it the wheel is out of true vertically or horizontally the pad will not have good or consistant contact
with that kind of thin steel side pull caliper brake
adjustment to in pad alinement can be performed by slightly twisting the arms
the normal alinement is toe in so the leading edge of the pad makes first contact
after this contact the brake arms and pivot points flext to bring the trailing edge of the pad into contact
only have as much toe is as to compensate for the flex of the arms
too much will result in un even pad wear
with cheep side pull caliper brakes the mounting point is secured by three bolts
these need to be adjusted so that the main spring is evenly aliened so the brake pads maintain the same distance from the rim as each other
and also that the two brake arms do not wobble about, yet are free to move
