Re: Brake Bleeding Problems in 105 series

[ALLSTEELDA@xxxxxxx]

Ten years ago I had problems getting the brakes in my '67 GTV bled after
installing a new MC and rebuilding the calipers.  In the end, several method
were tired and here are some suggestions that have worked for me over the
years.

First, it is important to keep in mind that you may well have air pockets in
any high points in the system.  Addtionally, keep in mind that your M/C and
your Mity Vac? pump can't really pump much presure or create much vacum if
their is no brake fluid in the M/C or Calipers.  If I found my self in your
situation, this is how I would proceed.

1.  Perform a gravity bleed:  Raise the entire car, place it on jack stands.
Make sure you have a full fluid level.  Retain the brake pedal on the floor.
Open the right rear caliper bleeder, attach a clear hose and a vessel for the
old brake fluid and wait a few minutes.  If you are not getting any fluid.
Try the following:  A. Open the fitting on the end of the M/C until the fluid
drains out and re-tighten.  B. Open the brake light presure switch until fluid
drains out.  C. Open the rear brake proportioning valve until fluid drains
out.  By now, you should be getting fluid to the right rear caliper. If so,
allow the fluid to flow until now bubbles appear in the clear hose, close the
bleeder, pump the pedal (slowly!) several times, brace in a fully depressed
position and proceed to the other calipers (LR, RF, LF). Follow the above
proceedure. This should result in a nice, high, firm pedal. I like this method
and it almost allways works for me.  Additonally, you reduce the risk of
ruining your M/C because of the limited amount of fluid in it ( too much
friction for the seals).  Further, you don't have to worry about drawing air
through the bleeder threads with your Mity Vac.

If you try this and still haven't bleed the brakes completely (it does happen)
here are some other ideas.

2.  Make sure the bleeders on the calipers are at the very top so that no air
can lodge itself at the highest point of the caliper.  Sometimes you may have
to raise the rear of a 105 car higher than the front to accomplish this. At
times I remove the calipers (keep the brake lines attached however) and move
them around while gravity bleeding to dislodge any air.

3.  Perform a pressure bleed:  You will need to make or buy a tool for this.
I just used a spare cap from a M/C resevior, drilled a nice clean hole slighty
smaller than the diameter of my clear plastic tubbing I use for my Mity Vac.
I then suff the end of the clear plastic tubing into the hole in my spare cap
to form an air tight seal.  I then set-up my Mity Vac to force fluid under-
presure in to the resevior (rather than suck-it out). I pump-up the Mity Vac
to about 10 pounds of presure (Warning: don't use too much pressure you will
make a big mess when the presure overcomes the cap's seal!!) and bleed each
caliper using the same proceedure as the in the gravity bleed described above.
Snap-on makes a neat tool for this too $$$.

Please excuse my spelling!  I'm in a hurry.  Any other ideas out there!

David Alexander
Riverside, IL

------------------------------