[s-cars] Help with RR caliper install?

[Fred Munro]

Hi Dave;

If the e-cam return spring seems weak, the cam shaft and/or mechanism needs
cleaning and lubricating; the cam should return to the stop without the
spring attached.

Too bad about CTC - maybe it got too expensive supplying new calipers at
rebuilt prices :o)

You don't need to fill the caliper prior to installation. I've found that
the MightyVac doesn't make a good bleeding tool - it pulls air around the
bleeder screw threads and gives a false positive for bubbles. I built a
pressure bleeder that works a lot better, I'll send you a .pdf write-up that
shows a photo of it via a separate e-mail Dave. Try the trusty old "have the
wife pump the pedal while you work the bleed screw" approach.

If you can move the cable by hand without grunting it is probably OK for
now. It should slide easily in the sheath; if it takes a bit of force it may
be starting to fail. The outer sheath typically breaks at the inboard
mounting block, allowing water into the casing and corroding the cable. I'd
hook it up and try it while the wheel is off to see if the cam returns to
the stop. Even if it doesn't I'd leave the cable on until it is replaced -
you never know when you will desperately need the e-brake. Just don't use
the e-brake unless you have to.

When the brake clearance is properly adjusted you should still be able to
turn the rotor fairly easily, otherwise the parasitic drag would eat into
fuel consumption and keep the brakes hot. To set the initial clearance, all
you do is pump the brakes - this moves the piston out. Be careful with the
e-brake cam cranking - I did that years ago during my first e-brake cam
cleanup job and locked the pads to the rotor. I had to drive the caliper off
the pads and screw the piston back into the caliper to restore clearance.

HTH

Fred Munro
'94 S4

-----Original Message-----
From: s-car-list-bounces at audifans.com
[mailto:s-car-list-bounces at audifans.com]On Behalf Of Dave Forgie
Sent: January 10, 2004 8:53 PM
To: s-cars
Subject: [s-cars] Help with RR caliper install?


S-gruppees: Sorry to be a pain but....I need some help/advise with my RR
caliper install.

The old caliper probably isn't/wasn't  that bad.  The e-brake cable
wasn't totally seized and I can push and pull it; however, it isn't all
that smooth.  I looked at the ebrake cam as per Fred Munro's post at
UrS4.com and it  was no where near as corroded as that.  But the return
spring sure seems weak.  In the meantime,  because I wasn't sure what I
would find when I tackled this today, yesterday after work I bought a
rebuilt caliper (its a Girling rebuilt by FENCO as a C8484).  Cost from
LORDCO (a local BC firm) was CDN$118 plus taxes (Fred: Canadian Tire no
longer stocks them, but if they did, the cost would have been $122).
Core charge was $117. (My RR wheel was quite "warm" when I got home last
night  because I had automatically (stupidly) used the ebrake on Thurs
morning. (Duh)  (Only 6 km one-way trip)

Here are my problems:

1.  I didn't fill the caliper with brake fluid (Pentosin DOT 4) first
because I knew I was going to use my MitiVac to bleed it.   So far I
haven't quite filled the little "cup" that comes with the MitiVac.  I am
still getting bubbles.  When will I know for sure when I have a) filled
the caliper and b) I have all the air bubbles out (the brake line
connection seems to be higher than the bleeder screw)?

2.  I am not sure if the ebrake cable is f*'d or not so, at this point,
I have not connected it to the caliper.  I am paranoid about the e-cable
causing the "new" caliper to stick "on" again.  I guess I don't know how
mch effort a push/pull it takes with good cable (i.e. I have no
reference to judge whether by cable is normal or screwed).  Should I
connect it and hope for the best or just leave it off for now? (I know
this means that I won't have emergency brake on the right side AND I
will have to adjust the RR brake by hand until the cable is replaced.

3.  Because I don't have the ebrake cable hooked up, I have been moving
the piston out to its running position by cranking the ebrake cam by
hand (okay, with a screw driver). At this point, the pads seem to be
touching the caliper but I can still turn the rotor relatively easily.
It seems like this is where I should quit (I don't want to over
"tighten" the pads onto the rotor - I won't have gained anything.) Any
BTDTs?

Thanks in advance to any and all who reply.  (I would like to finish
this "solution" one way or the other tomorrow (Sunday) if possible - now
I remember why I take my car to my trusted mechanic - he knows these
answers - but doesn't work weekends (and I need the car on Monday AM)).

Dave F (from now snowless but grey, wet and damp Vancouver)



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