Just wondering your input on this. My 8" booster with 12" of vaccum doesn't cut it. The booster rod was in the lower hole ( power brakes ) on the pedal and the pedal was very hard, couldn't stop! I ended up shimming the booster to meet up with the upper hole ( manual brakes )and now I can lock up the front brakes! The problem is the pedal is around 3/4" higher and has more travel. Is this what would happen? I am thinking I have to adjust my rear brakes to make it a little better reaction? Would that be an idea?

Thanks

The upper hole is closer to the ideal 90 degree angle between the pedal and the push rod than the lower hole. This will allow you to place more force on the push rod and may explain why you are now able to lock up the front brakes. The pedal height is a mystery to me. The pedal should return to the top and rest on the stop using either hole, or do you actually have 3/4 inch of free play when using the lower hole? If you are using a proportioning valve it may need to be adjusted to apply more pressure to the rear brakes.

You know what happened. When I removed the brake switch stopper bracket from the top hole the pedal came up 3/4 inch more. I adjusted the switch back down the distance of the bracket. Now it is where it was. I also re adjusted the rod so there was no play. As soon as I touch the pedal I see brake fluid pop out of the master. Thats good so far. I remember when I was younger when I adjusted my rear brakes my pedal travel was less. Am I correct? I may give it a try if I'm right.

If the rear brakes are out of adjustment it would have an effect on your response. I think the rear brakes have automatic adjusters on them just like the front, but I am not at home at the moment to check my books. Perhaps someone else will chime in, if not I will check it tonight. The adjusters do tend to seize up and stop working. Do you have a four drum system or front disks and rear drums?

I'm going to check the rears tonight. I saw 1 adjuster hole on one side but not the other??? Disk in front drum in rear.

With disk front and drum rear usually people have the opposite problem, rears locking up. Do you have a proportioning valve in the lines to the rears? It may need to be adjusted.

With disk front and drum rear usually people have the opposite problem, rears locking up. Do you have a proportioning valve in the lines to the rears? It may need to be adjusted.

I believe there is a proportioning valve, if thats what I'm thinking of. It's mounted to the frame rail below the booster. I don't think it has an adjustment.

I don't think the stock porportioning valve has an adjustment knob on it, though it may be adjustable internally. Most aftermarket valves do have an external adjuster. My disk/drum system is not stock so I can't be of much help to you there, sorry.