Hydraboost issue... or maybe just brake issue?

[I Have No Idea]

Hey guys,

Im coming to the final stages of my build on my 69 c10. I have been driving the truck for about 3 months on and off trying to work out any bugs before tearing the truck apart and having the chassis (roadstershop) powdercoated.

Let me first start by saying that everything is brand new on this truck, except the body. Parts that are on the truck now with the area im having issues.

CPP Hydrastop (hydroboost) system.
CPP Billet Proportioning valve
OEM GM LS Hydroboost power steering pump with the separate return.
CPP front disc assembly.
Bear ss4+ system without parking brake.
Lokar Billet brake pedal
Stainless lines and flex fittings at each wheel.


My issue im having is a very loud semitruck/train like squeal when braking slowly. Does not happen when they are aggressively pressed. Also the brake pedal seems to return kind of slow. Also if I come to a stop and then put the truck into reverse, I feel a chatter like they are dragging. If I apply pressure ever so slightly to the pedal it goes away.

I have put the truck in the air and spun the wheels and the brakes dont drag. With and without the vehicle running. The shaft that connects the pedal to the hydroboost unit is perfectly aligned and there isn't anything binding or pressure on the unit.

The brakes work flawlessly and I love every aspect about them except this. I have followed Baer's brake in/bedding/seasoning of the pads and rotors. and still nothing. I feel so bad driving this truck because of this. I have read almost everything on different forums and have gotten no where. I could really use some help here! hopefully I can get this figured out!