Weird brake problem

[ScoobyDoo]

This is my first post on your site, nice site too I might add. Has alot of great info.

I have a 69 930 (1 ton) that is suffering from a weird brake problem and am unable to nail it down.

The problem is the rear brakes provide almost all of the braking and when its wet out the thing is just a nightmare to drive.

The master cylinder has been changed and all the lines bled many times so air is not the problem. It will also brake straight so a bad flex line is not really an option as well.

I took a picture of the booster master cylinder set up just in case what is on there is not what it should be.

Thanks a bunch


Jason