Of these pics, which might be a possible vacuum source?

[fordhombre]

Okay, I realized that the Edelbrock carb sits on a spacer between the Holly intake and the carb. There are male ends on both the carb and the spacer, and I tried connecting the brake booster's vacuum line to both of them, to no avail.

The brakes need some more bleeding I think, because it takes a couple of pumps on the pedal to build pressure, but it WILL build pressure without the engine idling.

So my question is...Where is another source of vacuum for the booster? I found an allan bolt dead-ending a spot on the intake. It's between the carb and distributor. It's shown in one of the pictures. Does this section of the intake allow water, fuel, or air? Could this possibly be a vacuum source?

I found no other lines coming from the intake that weren't fuel or water. There is nothing running to the transmission that I could find.

[68F250]

The allen head plug on the #5 runner is a vacuum source, you could connect it there but I don't understand why it's not working on the other two sources you already tried.

[fordman]

dude bleed the brakes first. on my stock 390 intake the brake booster hooks directly into the intake. my pvc vavle goes into the back of the carb. try that and see what happens it should work.

[QC]

Either one of those vacuum ports should work. Check the check valve where the vacuum hose attaches to the booster also.

[fordhombre]

Okay, everything seems to be working all right, but the brakes don't catch (and they still catch well) until the pedal is almost to the floor. Maybe it's my pedal linkage being too short?

[heep70]

Maybe it's my pedal linkage being too short?

Did you change things as far as pedal linkage?

How about adjusting the brake shoes?

[QC]

Did you just convert to power brakes, or is it stock? I think the hole in the master cylinder piston that the pushrod goes into is a different depth on the power brake m/cyl than the manual m/cyl.
If you don't have the correct pushrod/piston combo you won't get enough stroke.

[fordhombre]

Okay, I now hang my head in shame...

what was happening was the pedal-to-booster-rod bolt wasn't tightened, and that created about 2 inches of slack that the bolt would give way abling the pedal to move. So when I pressed down the pedal where it would normally begin braking 1/2 way or so, it was then braking at 3/4 the way depressed.

I guess I've made it a habit of trying to find complicated solutions to simple problems.... bad curse!