Low Rear Brake Pressure

[Johannes]

Problem: Low rear brake pressure

How I know: Measured at the Brake Master Cylinder (200psi REAR PRESSURE).
(1500+psi TWO FRONT BRAKES PRESSURE FITTINGS)
Checked my friend's rear brake pressure, same m.c. and the result is 900psi.

Tried Solution:
1. Changed Master Cylinder to new one, re-measure brake pressure, still low for the rears.
2. Adjusted brake booster push-rod per specification, checked brake pedal in-cabin.

Video (to shorten things up)

SpY_qmNK5X4

[cotbu]

You seem to be approaching it in a scientific manner, but... you don't understand the system and what needs to be adjusted. Before I tell you what you should adjust, I'll try to explain too you what you've just did. Think of it as a global change, by adjusting the push rod sort of like adjusting fuel pressure to achieve a nice afr, whether it be at idle or wot. It's global so both are affected, tweaking certain areas of the fuel and timing maps would be a more specific change not affecting both areas at the same time. HTMS. anyway you need to adjust bias for the rears pressure to move up. Once that has been done, using the push rod too even the feel would most likely need to be done.

Did you upgrade the BMC or did you do an oem replacement?