Rear Brakes (LONG REPLY -detailed instructions)
SuffolkD at aol.com
SuffolkD at aol.com
Tue Aug 10 22:24:54 EDT 2004
To: "Derek Pulvino" <dbpulvino at hotmail.com>, 200q20v at audifans.com
From: Peter Schulz <pcschulz at comcast.net>
Subject: Re: Rear Brakes (LONG REPLY -detailed instructions)
the uneven pad wear on the inner and outer pads means the caliper sliders
are not working properly over their travel range.
This may/may not be due in part to a torn slider boot - you will have to
perform a visual inspection to be sure....the boots and caliper guide pin bolts
are available from the aftermarket and dealer sources, and the piston boot and
seal from the dealer (if necessary). ebrake mechanism seal is available from
NAPA part number 6405:<A HREF="http://www.napaonline.com/cgi-bin/ncommerce3/ExecMacro/NAPAonline/search_results_part_num.d2w/report?Search_Part=NO&ic_exact=YES&part_number=CR%2016X24X7">
part_number=CR%2016X24X7</A> price is $2.99 per seal.
Caveats..I am not a professional mechanic, this info is gained from BTDT and
numerous Quattro list references throughout the years ( Scott J for the
compression tool, Fred Munro for his info on the urs4 web page, Chris Miller, Mike
<A HREF="http://www.20v.org/brakere.htm">http://www.20v.org/brakere.htm</A> has pictures of the Lucas/Girling rebuild
instructions, the dissambled caliper and the tool used to compress the piston
-17mm 6 pt socket - 1/2 inch drive/breaker bar to remove wheel
- torque wrench
- Lisle piston or other piston retraction tool of your choice
- narrow 15/17mm open ended wrench ( to hold guide pin in place when
loosening guide pin bolt ( I use a Park bicycle cone wrench that I purchased at a bike
- 13mm 6 pt socket and drive ( caliper guide bolt)
- 11mm 6 pt deep socket ( brake bleeder)
- 11 flare nut wrench ( brake bleeder)
- needle nose pliers/vise grips
- container/pan to catch brake fluid
- plastic plug for brake hose to stop brake fluid drip
- brake bleeder and hose for bleeding
-14mm flare nut wrench for brake hose
- Dot 4 brake fluid
- plenty of rags
- 600 grit sandpaper
- brake cleaner
- brake grease ( I used hi temp synthetic)
Caliper removal, rebuild steps as follows:
Emergency brake off
car in 1st or Reverse
wheel chock placed
jack up car, set jackstand, remove wheel.
spray the brake hose and bleeder with your rust penetrant of choice.
carefully remove ebrake retraction spring with needle nose or vise grip
carefully loosen 14mm brake hose ( just to crack it a bit)
remove caliper guide bolts ( 13mm) x2
lift caliper free of the carrier
remove pads and note location of inner/outer pad
remove ebrake cable using pliers to lift it out of the ebrake lever cam on
remove brake hose from caliper by rotating the caliper off the brake hose.
plug brake hose to minimize lost brake fluid.
drain brake fluid from caliper into container
(WEAR EYE PROTECTION!!!!)
mount caliper in vise
use caliper retraction tool of choice to remove piston from caliper body (be
careful to not tear the boot. lubricate it if necessary with brake fluid)
carefully remove piston seal in the caliper bore
remove brake bleeder ( use 11mm deep socket wrench)
compress "cage" inside caliper body ( see website for a home made tool) this
relieves tension and makes it easier to remove the circlip
using either narrow circlip pliers or a pair of awls, remove circlip (WEAR
remove piston rod and other parts including "peanut"
remove the ebrake cam/shaft
clean inside of caliper with brake clean or other brake compatible solvent.
examine seal around ebrake cam - if there is corrosion on the ebrake cam
shaft, I recommend you replace the seal as it has failed with the NAPA
transmission seal BTDT.
clean clean clean - remove the grease from the ebrake shaft bore in the
caliper body, clean the parts///
clean the rubber seals with alcohol or brake fluid
lubricate the seals with clean brake fluid
polish the piston if necessary (600 grit)
remove corrosion from ebrake mechanism and polish with increasing grades of
put grease into ebrake piston bore
install new seal if necessary
install ebrake lever mechanism
install the small parts in reverse order of dis assembly - be sure to not get
grease inside the main piston bore.
compress the spring retainer and re install the circlip
lubricate and re install the piston seal
lubricate and pull the piston dust cover over the end of the piston and seat
the other end of the seal againstthe caliper body
gently turn the piston into the caliper body using a clock wise motion.
Ensure that the dust boot stays seated in its groove on the body.
If you have done very thing properly, you will see that the ebrake mechanism
will spring back with the assistance of the external spring.
clean and polish the caliper guide pins (if necessary)
clean and lightly lube the guide pin boots Reinstallation
reinstall the bleeder
reinstall the brake hose onto the caliper, tighten with 14mm flare nut wrench
reinstall the caliper onto the carrier.
grease and reinstall caliper guide pins
reinstall 13mm guide pin bolts (locktite blue recommended, torque spec in
Bentley, again use slim 15/17mm open end wrench on guide pin to prevent rotation)
reinstall ebrake cable
reinstall ebrake spring
check all connections.
use brake bleeder of choice and thoroughly bleed the caliper
AGAIN check all connections, bolts, etc
reinstall wheel, torque wheel bolts to 81 ft lbs
operate hand brake repeatedly to reset caliper
pump foot brake repeatedly with ignition on until pressure returns - if the
pedal stays "mushy", rebleed.
Done....now repeat for the other side.
Audience...feel free to make any corrections/additions..., and I will post to
the audifans knowledgebase.
At 09:24 PM 8/8/2004, Derek Pulvino wrote:
> Ok, I've got the Bernie method rear brake low pad indicator going. Looks
> like the caliper is going to need some refurbishment as well as on the driver
> side rear, the inside pad is worn, but the outside pad has much life left. I
> read through the information on rear calipers on Chris's site and it looks
> pretty straightforward. Any other btdt that I might want to be warry of
> before I jump in? Seal or boot kits recomended to purchase? Also looks like by
> cleaning everything up, I should get a functioning e-brake again, true?
> Can someone confirm that even though this sounds really ugly, it's not going
> to damage the rotor...as long as I don't let go like this for a long time?
1991 200 20v Q Avant Titan Grey
1991 200 20v Q Avant Indigo Mica
1990 CQ silver (awaiting S2 transplant)
1985 4000s Q....black and peeling CC
More information about the 200q20v