Brake bleeding, rear wheels

["Meron" <phwomp@cosmoslink.net>]

To all, 
I have not been able to pressure bleed the rear wheel, here are the
details:
subject car is 86 5Kcstq wit ABS

-I rigged a pressure cap to allow compressed air into the MCylinder and
used 10-25 PSI for pressure 
-the strainer is removed from the MC
-the MC is full of pentosin
-the ABS is turned off with the ignition off
-the ABS is turned off with the ignition on
-the ABS is turned of with the car running
-the ABS is not turned off, car not running
-brake pedal pushed in (mechanically, via a bar between the seat and the
pedal)
-bled the  MC, plenty of pentosin from both lines
-bled the brake lines after the ABS hyd. unit, steady run of fluid but not
a gayser!
-moved the lever of the brake proportioning valve lever, no difference
-bled the brake proportioning valve, very little pentosin
-looked for a hight sensitive proportioning valve, did not find any
-looked in the Bentley for brake bleeding procedure, NOTHING Helpful
(looked in two books 85-89 and 89-92 no help
NO PENTOSIN at the rear with all the above steps!!!!!!!!!!!!!!!!!!!
front bleed OK (with car off and  ABS is normal position)

What am I missing guys and gals, must be something, I surly should be able
to pressure bleed the rear, right??
Car runs fine brakes work same as always

Avi Meron
86 5Kcstq with unbled rear calipers