Author Topic: bad brakes  (Read 4022 times)

0 Members and 1 Guest are viewing this topic.

Online Vettech

  • Supercharged
  • ******
  • Posts: 1382
  • The rocket sled in Steel Blue.
  • Location: Cecil Hills. N S W.
  • Mood: Electrofied.
  • Car: C3 78 + C4 87 + C4 90
Re: bad brakes
« Reply #12 on: February 15, 2017, 03:25:29 PM »
If they are the orginal seals and disks out of square, and as they sit off the disk by only a thou or two, then they will be wobled by the disk causing them to suck in air.
The replacement style are I think "O ring" type, and seal better than the square setion seals, used in conjuction with S/S sleeves, once bled are great. I had continual issues like you on a 78, once overhauled (s/s sleeves o/ring braided line) I never touched them again AND it now stopped on a dime.

Offline Chris Jurgeit

  • Newbie
  • *
  • Posts: 3
  • I'm new here
  • Location: Sydney
  • Mood: Always good
Re: bad brakes
« Reply #13 on: February 18, 2017, 11:47:21 AM »
I had heaps of trouble with my '68's brakes.  I'd bleed them, drive for a day or so, and the peddle got longer.  I did the usual - braided lines, new master cylinder, new front calipers (they were replaced because of seal failure and fluid leakage).  Back calipers 'seemed' ok.  No leaks in system, but still the long pedal issue persisted.  In the end I bit the bullet and bought new stainless piston-seal rear calipers and pressure bled the system again.  To date (six months) my pedal is good.  When I inspected the old rear calipers I found a hairline crack in the cast iron of one of them.  This was on the inside of the caliper and couldn't be seen unless the caliper was damp, then dry.  The moisture identified the crack, much like magnafluxing I'm guessing.  While I'm not 100% certain, I think the crack was letting air into the system, but not letting fluid out.  For what it's worth....