[urq] Stopping Power: 100%- 50%- 10%- AAAHHHH!

[Maurits Jonkergouw]

The relatively small prop. valve (mounted beneath the master cylinder) does not leak so I ordered the Repair kit for Tandem Master Cylinder (P/N 183 698 181 B), just in case. 

Do you think this is an DIY job (do you have any R&R info on that?) or is it better (and less messy) to leave this to my local repair shop or Audi-dealer i.e. how complicated is it: could any non-Audi (but experienced) mechanic rebuild the Brake MC?

Thanks again.

Regards,
Maurits

  ----- Original Message ----- 
  From: "Ado Sigal" <a.sigal at bluewin.ch>
  To: "Maurits Jonkergouw" <urq at moregraphics.nl>
  Cc: "Audifans" <urq at audifans.com>
  Sent: Thursday, April 14, 2005 9:26 PM
  Subject: Re: [urq] Stopping Power: 100%- 50%- 10%- AAAHHHH!


  Same symptoms exhibited with my '86 GV, have a look at proportioning 
  valve first. It leaks around the cylindrical tension spring cover. After 
  examining the failed unit, I decided to use 90 Q one since it has all 
  internal components, so it can't ever leak, but it has to be mounted 
  vertically. Adopted original bracket and bent lines to suit and no more 
  worries. The original spare unit still sitting someplace in the garage.

  HTH, cheers,

  Ado

    ----- Original Message ----- 
    From: "Ado Sigal" <a.sigal at bluewin.ch>
    To: "Maurits Jonkergouw" <urq at moregraphics.nl>
    Cc: "Audifans" <urq at audifans.com>
    Sent: Thursday, April 14, 2005 9:26 PM
    Subject: Re: [urq] Stopping Power: 100%- 50%- 10%- AAAHHHH!


    Maurits Jonkergouw wrote:

    >In just a few days the brake pedal went from 100% to 50% the first 2 days, then it got 10% the 3rd day and today it went all the way to the floor while driving it in busy highway traffic... THE HORRER!
    >
    >I've already searched my audifans mailboxes and found several options: worn pads/rotors, boiled fluid, bleeding, bad bomb, bad master/slave cylinder, leaking/rotten hoses/lines.
    >
    >I did the bomb test with the engine off and the pedal becomes hard after 8~10 pumps accompanied with a loud metallic squirking noise, like it's dry or something. The brakefluid level is normal. After turning the engine the pedal went soft again to the bottom, but it returns normal, although slower then normal.
    >
    >I've quickly checked the hoses and lines and they are not showing any leaks, nor does the master cylinder. The pads/rotors are not worn either.
    >
    >My personal diagnose would be the bomb (I hope), but perhaps I'm wrong. Please share me your thoughts.
    >
    >Car had G60 conversion in mid 2001. No problems since, untill now after 60.000 km...
    >
    >Thanks in advance.
    >
    >Regards,
    >Maurits
    >
    >1986 GV (Swiss WR) 291.000 km
    >1985 CGT KV
    >1982 GL DD