brake lines problem

[Ti Kan]

chris franz writes:
> Ok...So I changed the pads on my 86 4000q.    The back went well and the 
> front was ok except I lost a lot of brake fluid (had trouble speading the 
> caliper so I opened the brake line to relieve the pressure).   Added more 
> brake fluid and tried to pump the pedal to push the air out of the line.    
> Pumped for a while and figured I got it all so I refitted the line.   Now I 
> don't have any pressure in my braking system.   Pedal is pushed to floor 
> with little resistance.    I figure that I still have air in my lines but I 
> don't know the correct procedure for removing it.    Can some one tell me 
> what to do?    Thanks in advance.

Just pumping the pedal with the line open isn't going to purge the line
of air.  On the downstroke you'd push fluid out, but on the upstroke
you'd suck air back in.

What you need to do is a full brake bleeding procedure.  Starting with
the wheel farthest from the master cylinder and do all four wheels.
Without a pressure bleeder this would be a two-person job.  Get someone to
operate the brake pedal while you open and close the bleeder screw.
You should get a transparent glass jar and fill it with a bit of
brake fluid, then connect a piece of tubing to the bleeder screw, with
the other end immersed in the glass jar's brake fluid.  With the bleeder
screw closed, ask the pedal operator to pump the brake a few times, then
press down on the pedal and hold while you open the screw.  You should
see air bubbles float up in the jar from the tubing.  Close the screw then
ask the pedal operator to let up on the pedal.  Repeat this over and over
again until you don't see any more bubbles coming out of the tubing.
Check the brake fluid reservior and top up periodically while you do this
so you don't run out of fluid in the system.  Do all four wheels until
you get a firm pedal with all screws closed, and make sure that the pedal
will not sink to the floor over time when pressed.

-Ti
01 S4 2.7 biturbo quattro
84 5000S 2.1 turbo
80 4000 2.0
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