Having spent more of my life in the flatlands of the midwest than I
would like to admit, I became accustomed to the idea of old cars having rust and corrosion on every single part.
As most of us know, 2002s and other cool old cars have a particular
problem with rust. Mostly, it's the body that people talk and worry
about, and rightly so as it's the most difficult and expensive to
repair. But rust affects the cars in other areas too.
Brakes are a particular problem area for the corrosion that happens
when you add water to metals then leave them exposed to the air. Then
throw in a little road salt here and there...
I'll start off with a simple caveat about brake fluid. It is
hygroscopic, which is a ten-dollar word that means the stuff absorbs
water. When brake fluid absorbs water, it becomes compressible, and
doesn't work as well. This means spongy, soft brakes on a car or
whatever that has sat for a while or has not had it's brake fluid
changed often. This also leads to a greater chance of corrosion in the
brake system.
How often should you change or flush your brake fluid then? If it's
dirty or looks like cola, soon! On a street car, yearly at least. On
a track car, where you want all those nasty bubbles gone, before every
event, sometimes even between sessions. There are certain
high-performance, high-temp fluids available that are great for racing,
but they are also costly. Don't bother with the silicone stuff; it
causes problems with seals for the most part. Just go ahead and use
fresh DOT-4 fluid and bleed it well and you'll be just fine.
An easy point to start with is to get all the fluid out of the
reservoir and clean the reservoir of any dirt and grit with paper
towels and q-tips. Then fill it with fresh fluid and bleed until no
more dirty fluid or air comes out of the bleeder screws.
Old-fashioned bleeding, with someone like a girlfriend or wife pumping
the pedal while you, the car guy, gets down and dirty opening and
closing the bleeder screw, works just fine. The fancy pressure
bleeders also work good, but they can be costly since you'll usually
need an air compressor to run them.
Whatever way you chose to bleed your brakes, don't forget to bleed your
clutch slave cylinder too. Lots of shops like to ignore this little
fella on the transmission, resulting in a clutch pedal that feels soft
and a clutch that may not disengage completely.
Then the hoses are another factor. Even though they are rubber and
waterproof, on old cars like our 2002s they deteriorate with time. If
you have erratic braking problems, especially up front, it may be that
the hoses have swollen shut on the inside. My younger brother has a
'76 '02 that the previous owners replaced the calipers and rotors on
but it still pulled and shook whenever the brakes were applied. He
took off the hoses and could not even put a needle through them! New
hoses made for a car that braked normally right away.
Back to rust. Those cute little bleeder screws are pretty fragile.
Not only do they rust, but if they are tightened too tight, they will
break off or the little hole in the bottom will be crushed shut. I
like to carry spares. Call me silly, but I like to coat the threads of
my bleeder screws with a small amount of anti-seize or teflon thread
sealing paste. They also come with little black rubber caps on them,
and those caps disappear awfully fast. This allows dirt to get into
the hollow center of the screw and prevents complete bleeding. Use a
small paper clip or drill bit to clear the center of any dirt.
But what if your bleeder screws are stuck tight? Of course, there's
WD-40 and Liquid Wrench to start with. Here I like to use a deep well
1/4 inch drive six-point socket on a small ratchet to loosen it
initially rather than a box or flare wrench. The more gripping power
on the screw, the better, and a six-point socket is less likely to
round off the flat sides than a wrench because it grips better. If
it's really bad, I like to use a hammer and small punch to gently tap
the sides of the screw prior to trying to loosen it. This works on
regular nuts and bolts too. If all this fails, it's time to go to a
torch to heat things up. If the screw breaks, you'll be busy drilling
it out and using an easy-out or something to remove it. Not fun.
The rust also affects the metal brake lines. They do rust out, especially
if near the sponge rubber that covers the lower part of the pedal box.
A regular auto parts store carries a selection of straight hard lines
that can be carefully bent with the right tools and some patience.
The rear wheel cylinders are mounted with two small bolts that thread
in from the backing plate. Yep, they are prone to rust, treat them
like bleeder screws, because they do break easily.
Speaking of rear wheel cylinders, the popular 320i rear brakes usually
have 19mm wheel cylinders, which work just fine on a 2002. There are
22 or 23 mm wheel cylinders available, and they will work even better,
but you will need a pressure limiter in the lines to avoid lockup.
Rear disc setups are nice, but you will need a proportioning valve to
adjust the brake bias, and you will need to buy a complete kit or have
someone fabricate mounts for the caliper.
On the backing plate there are also the brake shoe adjusters. Yes,
these rust too. Loosen them if you can, use antiseize paste, and
readjust them.
Rust happens to pedal boxes too. Keep the pedal shafts and linkages
cleaned and lubricated. And that foam rubber I mentioned earlier that
resides on the lower part of the pedal box is great for holding water
in contact with the metal if you live in a wet climate.
The biggest for last. That big nut that holds the rear hub on is a
36mm baby, and it is on there tight! I usually like to take out the
old cotter pin and have a local shop use their impact wrench to break
it loose. For five or ten bucks it's worth it. Then I finish the job
at home and stand on the longest breaker bar I can find to tighten it
to as close to 250 or so ftlbs. as I can. Don't forget to install a
new cotter pin just to make sure that nut stays put!
B
Happy Braking (breaking?)
You can email Vince Strazzabosco at: vstrazzabosco@yahoo.com
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