Packard Forum Index » V-8 (1955-56)

I had a 56 400 I purchased in 1962. The seller warned me of the sensitive brakes and suggested I get used to them in the alley behind the garage. They were very sensitive! I adjusted to them, but did warn my wife the first time she drove it.
My question is WHY aren't they that sensitive today?

On my 400 (BEST OTHER) I did have original Packard lining on the front wheels. The TV had been rebuilt by Ed Strain. Any theories (or known fact?) as to why that sensitivity is no longer there?

They are oversensitive when there is something wrong! There is a diaphragm inside the power piston which is supposed to give pedal feel, and make some compensation for changes in engine vacuum. If that is breached, or the passages to it are blocked you get a sort of on/off braking experience. Also, on the types used in 55 and 56 with the small poppet valves controlling the vacuum, poor pedal feel can result then their little rubber seals begin to fail.

Ross, The brakes remained consistent from 62 thru 65. They never required much pressure to bring the car to a swift stop. I don't think anyone replaced the power piston in my current 400 because I've had it since 72, except when Ed Strain and you rebuilt it. It still doesn't explain why the current BTV is not as sensitive unless you and Ed modify it in some way?

Wheel cylinder size can effect pedal pressure.But usualy requires a large varation from stock or whatever was on the car that was so sensitive.

So could it be a vacuum issue?
Is there a certain reading you can check to see if you have a leak in the system? Hose, or the vacuum canister, or maybe the diaphragm?

OR,
Maybe you were more "sensitive" back them 🤔😉

Naah Mike, if my wife were here she could testify I am NOT sensitive. You and I are thinking along the same line though. I am wondering if I have a vacuum leak OR perhaps the wrong type of hose and it is collapsing (partially).
Will check that and report back. Need to verify the vacuum tank hasn't sprung a leak first.

I would think any kind of vacuum leak would make the pedal harder to push and you would hear the hiss or have a rough or fast engine. Is that what you mean by less sensitive or does the lining not grab like before so there is more pedal pressure required to stop the car.

In the 70s I had a car relined after asbestos was banned and those new linings stopped like crap compared to the older OEM lining. First time I stopped after leaving the shop I almost hit something because the feel was so different. I took the car back to have it checked but they assured me that was the feel and said get used to it. I did.

The problem there Howard is that I had new original Packard lining installed that I purchased from Joel (packards1).
Back in the '60's all you had to do was lay your foot on the pedal and the car would stop quickly. So if I'm running the same lining and same BTV why isn't the pedal feel the same?
There is a conundrum here and I would like to know the answer. I can live with these brakes - just wonder what is different??

My friend Chris, who sold me Best Other in 1972 had a favorite warning for Packard V8 owners. He said the car drove nice, but you had to keep all the windows rolled up in the summer. WHY??
Because if you didn't a fly might enter the car and land on the brake pedal sending you through the windshield.
Those of us who drove 55-56 Packards back in the day got a chuckle out of that.

There are no changes in the vacuum section of the TV as there is nothing to change. I would agree with Howard and that the difference is mostly in the brake linings. I scored a set of old stock asbestos shoes for one of my Studes and it now has a delightful easy pedal feel.

If you have a vacuum leak big enough to notice in the feel of the brakes, you will surely also notice it in the running of the car, particularly at idle.