I have confirmed I have the rear port on the P30 connected to the rear brakes. Tested pressure again. Got 800 rising to 900 when holding on the rear MC port. 500 steady at the rear output of the combination valve.
Did not have parts to test at the input of the valve.
Neil
You are within a couple shovels of paydirt. You got a 300 - 400 PSI drop between the master cylinder and the output of the combination valve. I don't know or care how that can even be possible. But you need to figure out which component has the evil in it - the line or the valve. Disconnect the line between the master cylinder and the combination valve and verify there isn't anything in it that would restrict flow. Then do the same between the input and output of the combination valve. Might need to replace the combination valve. Reassemble, bleed the rears one last time, and drive it.
GMCforum
Search
Help
Register
Login
Home
