Pressure Bleeding experience + questions

["Michel Drainville" <MDrainville@xxxxxxxxxxx>]

I finally found time to pressure bleed (flush) my brake system on my E30
(91 318).

I made my own system with a Audi cap and applied a pressure or 18-20psi. I
had the car on jackstand, and started by opening a rear bleeder. To my
surprise, nothing came out. So I tought that the bleeder was rusted or
blocked, so I continued to unscrew it to see some fluid coming out, but
nothing! I had the bleeder removed and 20psi of pressure on the tank and no
fluid was coming out. I didn't understand. So I put the bleeder back, and
tried another one. Same thing. I found that three out of four calipers
seemed to be blocked, the bleeders were ok, I was able to blow air through
them.
Even with one bleeder removed, I pressed on the brake pedal with a moderate
effort and no fluid was comming out!!.
So I took a rigid wire, and fished it into the caliper hole (with the
bleeder removed) and then slowly the fluid started to flow.
I proceeded to clean/unplug all four calipers, then I was able to pressure
bleed the system.

Even if the pressure bleeding was working, I found that the flow of fluid
was low. I was convince to see a healty flow, but instead, it was at the
limit of a drop by drop and continious flow. So I went to do the clutch
slave cylinder and holly s***, it squirted three feet with a very good
flow. The way I tought the brake bleeding would have happened.

To make a comparasion , the brake bleeding was like an old man with
prostate problem, and the clutch bleeding, well, like you after a couple of
beer.  :-)

So, does the flow of the caliper should have been like the clutch?
If yes, are my calipers or lines full of rust or deposits?

If no, is that a result of the ABS causing a restriction?

Beside of that, the brakes always worked fine for the last five years, and
even better today, since I installed Hawk HP+ brake pads and BMW rotors at
the same time. I went to try the Hawks, (not the HP wich are the OEM
replacement but the HP+ which are for street and track) and wow, compared
to my Metalmasters they brake like hell, with no fade. Even after many high
speed braking tests, it was still possible to lock the wheels. The real
test will be at the next driving school.

Michel.

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