Hello everyone, ok heres the deal on my dad's 69 el camino. Looking for some help since hes been trying to figure this out for a while. It seems that the front brakes dont want to lock up, sometimes the braking power is good in the front and then it fades away. Heres a little history on what has been done.

Replaced front rotors with cross drilled from internet, calipers from autozone, replaced master cylinder and booster many many times, replaced front brake lines, proportional valve.

Everything bleeds properly, my dad was talking with someone and they mentioned that the pedal may need to be adjusted because of the rod in the master cylinder has to be in the proper position. The hole on the rod needs to visible when pedal is fully depressed. I never heard of this and was thinking that the hole should be centered when the pedal is depressed already from the mfg. Anyone ever heard about this before? Also when we push the pedal down fluid squirts out of the master cylinder fill bowl (with the cover off of course). Could it be the rotors or the pads causing the front end not locking up?? Any help much appreciated.

You didn't mention whether or not the proportioning vale was for disk brakes. Also, did you change the vacuum booster? Do you have 9" or 11" ? It's small details like these that will change the characteristics of the brake system.

sorry I didnt mention it. Yes the prop valve is for disk brakes, and I believe the booster is 11". Ill have to go out and measure. My dad just made a point that when bleeding the brakes is seems that there is more line pressure in the rear versus the front, not sure if that is normal or not.

Are the front and rear lines reversed at the m/c?

I had a similar problem recently and it turned out I sucked a little air into the master while bleeding and hadnt noticed, only the front effected do to slant of the master in the car. I had to pull the master off and bench bleed it al over again and reinstall. bungo now they work like a charm.Did you bench bleed the master before installing? sometimes thats all it takes.

on a stock 69 master the fittings should be two different sizes in the master so you cant get them backwards, unless you bought a different style or year.

on a stock 69 master the fittings should be two different sizes in the master so you cant get them backwards, unless you bought a different style or year.

Yes, in a perfect world. Having been in the repair business 36 years I have seen stranger things and this one more than once, all it takes is a little "ingenuity".

Strange how the world is seldom perfect under the hood of a 40 something year old car. You never know what your gonna find. stock it would have also had a hold-off valve piggybacked on the master for the front brakes too.

I thought about the lines being in the wrong place too, but we swapped them and it didn't change anything. We tried about 4 different m/c, we currently have a m/c and booster combo from a early 90's truck which is dual diaphram. Should help in stopping power versus the single diaphram, but still have the same problem. And each time we bench bled the m/c before install. Still don't see any air bubbles when pumping.