Parking Brake adjustment.

["David A. Leonard" <dleonar1@xxxxxxxxxxxx>]

Mike Wrote>>

Subject: adjusting parking brakes

hey, since it looks like we could use more posts,
I thought I'd ask an easy one:
how to tighten up the parking brakes.  I recall somewhere stating it
should only
take 4-5 clicks to fully set the brakes.  Mine sets in about 8-9.
I think I have to take off the cover in the console and tighten the
double nuts?
Is that all there is?  of course not.  so what else do I need to do?>>

Mike, I just did mine on my 88 735i

I didn't touch the console, all of the adjustment was done at the brakes.

The book sez you can adjust them through a wheel bolt hole, but in my
experience you really need to inspect the guts of the whole thing before
trying this.. though I can make a big project out of anything..

With this in mind:

Remove the rear wheels (obviously jack first)

Remove the brake calipers..inspect the pads.. you can just push the pads
back, and slide the whole thing off with the pads in it if the pads don't
need replacement.. I took the whole mess apart, and cleaned and greased the
slider pins and surfaces.

Undo the little allen screw that holds the rotor on..remove the rotors.

Inspect the parking brake drum shoes and make sure there is some shoe lining
left.

Assuming there is enough shoe left, and there doesn't need to be much, as
these brakes don't wear much if used for parking,  turn the adjuster gear in
the outward direction until you can just slide the rotor back on.

Put the car in neutral and pull up the brake to the point that you want the
brake to lock..I used five clicks.

through one of the wheel bolt holes, use a screwdriver to turn the adjuster
wheel until you cant't turn the rotor by hand..this will be the point where
the the brake begins to lock.  release the brake lever, and make sure that
the rotor can now turn.  If you want, turn the adjuster one or two clicks
tighter, then pull up the lever and it should become tight now at four
clicks.

Do the other side.. It is a little harder to feel how tight they are now
with the brake lever as you already have one side creating resistance..I
might just do the five clicks, tighten the adjuster to stop all turning,
release the brake, and turn the adjuster the same # of turns you did the
other side, and call it good.

Reassemble the brakes, I use "never sieze" on the little rotor allen screw
so it will come out in the future.  Mine came out easily at 230k miles, abut
it had been never siezed at 100k or so.  You probably broke it off trying to
get it out if it had never been out before.. Sometimes these things need
judicious hitting with a small punch before trying to turn them with an
allen wrench.  I saw a factory tech turning them out last week while hitting
the back of his allen screwdriver with a hammer.

There is a synthetic hi temp brake grease (NAPA) I like to use on the
caliper slide surfaces and pins.

The book suggests using the parking brake to stop slowly for 1/4 mile or so
from a slow speed in order to heat up the shoes and remove the glaze.

Go out and attempt to do some "bootleg parking brake turns " with your now
tight parking brake..it isn't very powerful, and you need some snow or ice
to lock the wheels...

Here is another ABS discovery I just made..after a bunch of ABS/years..

If you are sliding on ice or snow, and you want to get the wheels to
lock(sliding down a steep hill into traffic in freezing rain through a stop
sign comes to mind for me..with the ABS firing, and just wishing you could
get the damn wheels to lock..)  After adjusting my parking brake, I found
that if you can get the rear wheels to lock, the ABS computer thinks that
the car is going less than the 2.5 mph or so it looks for and shuts off the
ABS.. I think the system compares wheel speed to vehicle speed, and the
vehicle speed sensor is on the rear differential.

When it senses that the car is stopped.. no speed at the rear diff, and both
rear wheels .. it stops trying to modulate the brakes based on individual
wheel speed.. pretty cool, huh?

I'd like everyone to attempt this stunt and report in. Maybe its just my
imagination here, but I was able to repeat the experiment with consisten
results..Gary D.. help me out here..

Dave Leonard

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