[200q20v] re: misc (and brakes)

[Phil Rose]

Chris Miller said:
>The list has been very quiet; I'll assume that's because your cars are
>working so well.  Right?


Hmmm. Yep, and also because of spending much of the past couple of days
under my car doing long-delayed brake maintenance.

I finally got a new set of front brake rotors to replace the ones that
didn't survive my first few-dozen laps at Watkins Glen, a couple of weeks
ago. The new rotors are made by Zimmerman--a garden variety (not drilled,
not grooved) oem-type for the G60 brakes (with S4-type struts). I hope
these are at least equal to the (more) familiar Ate brand.

This was the first time I'd done brake work on an Audi. The job was pretty
easy, except for loosening the 92 lb-ft carrier bolts. For me, the 15"
breaker  handle was barely adequate--especially considering the difficult
angles. To me it seemed best to first remove the slide bolts and hang up
the "other" half of the caliper before trying to break loose those carrier
bolts. Then I cleaned and repacked the caliper slides, which were already
well-greased and moved easily. Rubber boots were OK, too.

I didn't have any new rotors available at the Glen when my old pads wore
through, but I put in a set of new pads just to get me back home. The pads
are semi-metallics ("Remsa" brand) and were the spares included  with the
car when I bought it 2 years ago.  I decided I'd continue with those pads,
but since they've now been used (lightly) for a few hundred miles with the
badly grooved rotors, I had to spend a few minutes sanding each pad surface
using medium grit emery cloth. This was done against the top of my
cast-iron table-saw--to assure good flatness. Was the hardest part of the
job!  Rotors, calipers and pads went together easily.

Today I did the brake fluid change I should have done _before_ the Glen
event. I put together a pressure-bleed "system" that allows it to be a
one-person job.  The basic approach has been described by various Qlisters
and typically involves a pressurized "feed bottle". At Chris Miller's
suggestion, I decided to simplify by eliminating the feed bottle, and
instead, the brake fluid reservoir would need to be topped up a few times
during the procedure. Here's what I did:

(1) I used a 25' coil of yellow plastic pressure hose ($6.99 at Pep
Boys)--these seem to be available everywhere--and I fitted it at each end
with an air-chuck that has a lever-actuated gripper (chuck with gripper is
about $6 each). This firmly holds to the tire stem and allows hands-free
operation.

(2) I fitted a spare brake-fluid reservoir cap with a metal, tractor-type
tire valve stem ($1.99 at Pep Boys) which is gasketed and has external
threads for a retaining nut. As a precaution, the fluid reservoir was taped
around (tightly against the master cylinder) with a couple of lengths of
duct tape.

(3) A spare tire was bled down to about 16-18 psi, and the hose was
connected to the tire and then to the modified reservoir cap. At this point
the reservoir is full of old fluid.

(4) I  attached a convenient length of tygon tubing to the (right-rear)
bleeder fitting, fed it to a waste bottle (Snapple "Lemon Iced Tea") and
loosened the fitting with an 11 mm wrench. It came loose pretty easily (all
fittings had the rubber bleeder caps and didn't appear corroded.) With that
initial 16 psi pressure,  the fluid flow is only moderate, but it took just
5-10 minutes to drain about 2/3 of the reservoir (old fluid), which is
roughly 8-10 ounces. At that point I shut down, and I topped up the
reservoir with fresh, Ate Super Blue  DOT 4 fluid. I reapplied pressure and
opened the bleeder and withing a few minutes the new (blue) fluid started
emerging. I let about 2  or 3 more ounces through and closed off the
bleeder. I topped up the reservoir and repeated the operation at the
remaining wheels (left rear, right fr, and left front). Altogether, I used
only a few ounces less than the full 1 qt container. I suppose that 1 qt
would be just about enough to also do the clutch, but I didn't get around
to that (yet.)

After bleeding the 3rd wheel. the ntire pressure  seemed to have dropped to
10 psi or less, so I decided I'd increase its pressure (using my bicycle
pump) back to about 16 psi. I may have been too conservative about the
starting psi and perhaps 20-22 psi would have been OK, in which case
there'd be no need to re-pressurize the tire. Better safe than sorry though.

I took some digicam pics and will send them to Chris, who may want to post
them on his website.


Phil Rose				Rochester, NY
'91 200q				mailto:pjrose at frontiernet.net