What am I doing wrong with my brakes?

[65PlymSatellite]

I realized I failed to mention that the only thing I have not replaced regarding the brake system are the Brake Lines. The original lines are in place, and before I started fixing up the car, it sat un-driven for about 20 years. Before I did the front disc conversion, I rebuilt the 4 drums and blew air through the lines to make sure they weren't clogged. I wonder if there is some kind of residue or 20 year old gunk that's not allowing the proper pressure to reach each caliper/drum cylinder?

 

[65PlymSatellite]

Also, drove the car again this weekend. The way I would describe the pedal feel at a "panic stop" would be like applying the brake slightly faster than normal in a modern car. I don't jolt forward the way I would slamming the brakes in a modern car. It's as if there is a delay in brake fluid being sent wheels, and not enough brake fluid being sent. Maybe my pedal ratio is off, maybe I should switch to Manual Brakes. Currently not comfortable driving on the freeway.

 

[Kern Dog]

I re-bled this weekend, and pedal felt the same. There was no air in the system.

I have dealt with a few systems that seemed to have all the right parts but they still did not play well with each other.
You might consider putting pipe plugs in the brake line ports of the master cylinder. If the brake pedal action feels the same, the problem is in the master cylinder or booster. If the brake pedal action improves, the problem is somewhere further down such as the brake hoses, proportioning valve, wheel cylinders or rear brake shoe adjustment.

 

[65PlymSatellite]

I have dealt with a few systems that seemed to have all the right parts but they still did not play well with each other.
You might consider putting pipe plugs in the brake line ports of the master cylinder. If the brake pedal action feels the same, the problem is in the master cylinder or booster. If the brake pedal action improves, the problem is somewhere further down such as the brake hoses, proportioning valve, wheel cylinders or rear brake shoe adjustment.

Great Idea, going to try that next.

 

[miller]

Was wondering if I might need a Residual pressure valve.

Maybe a word game. Do you mean, what I call the distributor block, where the brake lines go from the MC? What block do you have on it now?

On my 64, converted to disc/drum, using the disc-o-tech method, all stock parts. Not familiar with the Willwood stuff. But, including stock parts, the MC alone needs to be the right one for (in your case) power disc/drum. Normal MC for disc/drum, the two fluid pots are different, larger one, at the rear is for disc brakes. Is that Willwood anything like that?
And, at the distributor block, I used the correct stock block for disc/drum.

Everything else is basic, to make it work. Good deal you put hard lines on! With the car sitting for that long, yeah, everything needs to be checked. Instance on mine was the Y block on the rear axle. Dang thing had a piece of trash, from the flex hose, plug up the port. Bang head!
How ever you do it, be sure fluid is getting from A to B.

 

[Dragon Slayer]

If the MC is a disc drum type, there is a residual valve inside the MC for the Rear brakes. None on the front disc. What is your proportioning valve? Stock Mopar type or adjustable after market. It reduces pressure for rear brakes. So what type of distribution block? Just a basic one or a Mopar type with pressure differential switch and maybe more like hold off/metering valve for front?

Any idea if any of the brakes are gripping? Rear or Front?

 

[65PlymSatellite]

This last weekend, I put a pressure gauge on my driver side caliper. I was getting about 950 PSI to the caliper. I called Wilwood’s tech line and was told this was ideal. I was made to believe that 1200 PSI was needed AT THE VERY LEAST! What do you guys think?

 

[65PlymSatellite]

If the MC is a disc drum type, there is a residual valve inside the MC for the Rear brakes. None on the front disc. What is your proportioning valve? Stock Mopar type or adjustable after market. It reduces pressure for rear brakes. So what type of distribution block? Just a basic one or a Mopar type with pressure differential switch and maybe more like hold off/metering valve for front?

Any idea if any of the brakes are gripping? Rear or Front?

I have an adjustable willwood distribution valve.

All brakes are gripping. Just doesn’t seem to be enough.

 

[Frank Mopar]

This last weekend, I put a pressure gauge on my driver side caliper. I was getting about 950 PSI to the caliper. I called Wilwood’s tech line and was told this was ideal. I was made to believe that 1200 PSI was needed AT THE VERY LEAST! What do you guys think?

What about rear pressure?

 

[65PlymSatellite]

What about rear pressure?

Didn’t get a chance to check the drums, will do soon.

 

[CoronetDarter]

I converted the Coronet to front discs, kept the back drums. Installed the correct mc with a Bendix type booster, set the pushrod gap to 0.2" (i thought). Had excessive rear brake drag. Troubleshot the issue on and off for 2 years. Turned out it was a pushrod gap. On the bench I recalced the gap, and while tightening the mc nuts I could see the pushrod engaging the piston through the weep hole. Wound up going old school and adjusted the gap using a film of brake grease on the pushrod end until there was no transfer to the piston. Took a long time but it solved the brake dragging.

 

[65PlymSatellite]

UPDATE:

Last weekend I replaced ALL the brake lines in the car with an Inline Tube kit. Weekend prior to that, the brake line to the rear driver wheel cylinder broke EXTREMELY easily with a slight wiggle. That convinced me to replace all the lines. After that, the brakes were still not right. This weekend I decided to pull of the booster and do some measuring. I found an old thread on here that measured an original booster push rod from the firewall, and my adjustable push rod was roughly 1 1/2" short. Also measured the push rod to the booster, and there was gap I was not happy with. About a 1/4". Adjusted that too. Took the car out, and saw a HUGE difference. Was able to smoke the tires at a panic stop when before, I wasn't even able to make them screech. Pretty happy with the results and I now feel safe driving the thing. I do feel like I might benefit from going to a smaller bore MC, maybe 1" opposed to the 1 1/8" that I have now. Though first I have to deal with a Carb issue. When I was driving, there was a backfire that managed to destroy my muffler and tailpipe. Carb had been "burping" for a while now, and I'm now forced to deal with it.

Thanks for everyone's time and advice.