Rear Brakes (LONG REPLY -detailed instructions)

[SuffolkD at aol.com]

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)

Derek:

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">
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</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 
Sylvester, etc)

<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 
spring retainer

tools:
-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 
store))
- 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
- alcohol
- 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 
pliers. 
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 
caliper 
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 
rebuild procedure.
(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 
EYE PROTECTION!!!!) 
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 
sandpaper 
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 
lower vehicle 
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.

HTH

-Peter

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?
> 
> 


-Peter

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